# 280zx T vs. Prelude vtech



## Exile(SK-member) (Jul 23, 2004)

My friend has a 95 prelude vtech, he's pretty much stock except for a short ram and a lil fart cannon, lol. I'm bone stock. We're going to the track thursday how do I stack up agianst him. I pretty sure I can take him.


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## Marc Z31 (Jul 25, 2004)

before you go, spend $40 on a hallman boost controller, and bump that boost to about 10-12 psi. Unhook your exhaust BEFORE the cat too (the gains are huge and it's only 3 bolts) with those two things, you should be low 14's mabe high 13's. your friends lude will be lucky if he gets a 14. your competition will be stock LT-1 camaros, not rice junk. If you leave the Z alone, you will take the lude by a few tenths (like 1-3). spend 40 bucks and you will be very surprised.


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## chimmike (Oct 17, 2002)

has honda changed the program from vtec to vtech? I read honda vtech this and vtech that all the time.............................


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## Exile(SK-member) (Jul 23, 2004)

Is the hallman bc easy to install?? How much gain will I get from just unhooking the exhaust @ the cat, wont that be loud as hell?? And do I have to order it or can I go to autozone/advance. Cause I'm going to the track tomorrow.


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## Marc Z31 (Jul 25, 2004)

Unhooking the exhaust will not be as loud as you think, because a turbo acts like a muffler. The boost controller is extremely easy to install, and you can even make one yourself for about $5. it is a little difficult to tune, but it shouldn't take any more than 30 min. Drop a line to [email protected], he has this done to his 300ZX. All the boost controller does is trick the wastegate into thinking there is less boost than there actually is. One side of the boost controller has 12 psi, while the other side has the factory boost level. It is instaled in the vacuum line between the turbo outlet and the wastegate actuator (the round small canister mounted on the turbo) the gains from more boost are incredible. you will become a boost junkie for sure.


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## Marc Z31 (Jul 25, 2004)

chimmike said:


> has honda changed the program from vtec to vtech? I read honda vtech this and vtech that all the time.............................


V-tec is about the worst and most inefficient variable valve timing system ever made (exept the original system that honda jacked from porshe) Every other car company has a much better system. Toyota, mitsu, nissan, mercedes, GM, Ford, and especially BMW have much better systems. V-tec FEELS better, because it hits all at once, but it is this that makes it a poor system. Every other company's variable valve timing is ALWAYS changing, so you don't feel it, but it is working. The new i-Vtec is similar to the other car company's systems, but is still an inferior system. When you hear people talking about V-tec being the coolest, best thing since pistons, remind them that it's out dated and inferior, and all the really fast drag hondas are NOT V-tec. They use a V-tec head, and an aftermarket radical non-Vtec racing cam. When you ditch V-tec you drop a lot of valvetrain weight, and can spin the engine 800-1200 rpm higher, thus making more power with that large cam and heavy cylinder head porting.
Sorry, just a rant, I just think V-tec is total ass... ass and feet.


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## Exile(SK-member) (Jul 23, 2004)

Thanks for the info Marc ill be sure to post my slips up.


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## hondakillerZX (Aug 16, 2004)

i was going to do those things to my 300zx turbo too, i heard it was bad to run over 10 psi without an intercooler, please let me know if im wrong


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> i was going to do those things to my 300zx turbo too, i heard it was bad to run over 10 psi without an intercooler, please let me know if im wrong


 I run 15 psi with no IC. One good rule of thumb is no long distance boosting on the highway , the intake can heat up pretty dramatically , and engine knock can blow your headgaskets....... But for around town and just general ricer spanking , 13-14 psi is quite adequate. 14 psi is the supposed limit of the fuel system's capacity , but I ran 15 psi for a long time with no issues.


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## hondakillerZX (Aug 16, 2004)

cool man im going honda killing tomorrow i just got a boost controller. all they'll see is my emergency lights blinking (i love doing that to people after i smoke them they get pissed). oh yeah how long do u run your turbo at 15 psi with out it getting too hot? the heat will show up on my gauges right?


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> cool man im going honda killing tomorrow i just got a boost controller. all they'll see is my emergency lights blinking (i love doing that to people after i smoke them they get pissed). oh yeah how long do u run your turbo at 15 psi with out it getting too hot? the heat will show up on my gauges right?


 No , your gaskets would be long toast before the heat ever showed up on the guages. The turbo itself can take 15 psi ok , the stock fuel system and HG's can't do it for long without at least an IC and a fuel pump upgrade. 12-14 psi should be ok for short periods. 15 psi should be considered your _absolute_ limit.


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## KungFuGrandpa (Aug 23, 2004)

yeah i run my Z at 14 and it runs great with no problems either. I read that the stock comp and injectors could only hold up to 12.5psi and are only good up to 270hp at flywheel


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## KungFuGrandpa (Aug 23, 2004)

here is the site for the specs
http://www.z31.com/faq/turbo.faq.shtml


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## das280zx (Jul 17, 2003)

Marc Z31 said:


> V-tec is about the worst and most inefficient variable valve timing system ever made (exept the original system that honda jacked from porshe) Every other car company has a much better system. Toyota, mitsu, nissan, mercedes, GM, Ford, and especially BMW have much better systems. V-tec FEELS better, because it hits all at once, but it is this that makes it a poor system. Every other company's variable valve timing is ALWAYS changing, so you don't feel it, but it is working. The new i-Vtec is similar to the other car company's systems, but is still an inferior system. When you hear people talking about V-tec being the coolest, best thing since pistons, remind them that it's out dated and inferior, and all the really fast drag hondas are NOT V-tec. They use a V-tec head, and an aftermarket radical non-Vtec racing cam. When you ditch V-tec you drop a lot of valvetrain weight, and can spin the engine 800-1200 rpm higher, thus making more power with that large cam and heavy cylinder head porting.
> Sorry, just a rant, I just think V-tec is total ass... ass and feet.



Isn't v-tech not just variable valve timing, but also variable valve lift? You have to give them some credit for this as few cars actually have variable valve lift. Nissan doesn't even offer it in any cars in the usa, probably because it has engines that are big enough to make good power, but still.


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## morepower2 (Apr 19, 2002)

Marc Z31 said:


> V-tec is about the worst and most inefficient variable valve timing system ever made (exept the original system that honda jacked from porshe) Every other car company has a much better system. Toyota, mitsu, nissan, mercedes, GM, Ford, and especially BMW have much better systems. V-tec FEELS better, because it hits all at once, but it is this that makes it a poor system. Every other company's variable valve timing is ALWAYS changing, so you don't feel it, but it is working. The new i-Vtec is similar to the other car company's systems, but is still an inferior system. When you hear people talking about V-tec being the coolest, best thing since pistons, remind them that it's out dated and inferior, and all the really fast drag hondas are NOT V-tec. They use a V-tec head, and an aftermarket radical non-Vtec racing cam. When you ditch V-tec you drop a lot of valvetrain weight, and can spin the engine 800-1200 rpm higher, thus making more power with that large cam and heavy cylinder head porting.
> Sorry, just a rant, I just think V-tec is total ass... ass and feet.


Honda's vtec is one of the best variable cam timing systems avalible. Nissans VVL system is nearly a direct copy of it as is Toyota's system used in the Celica GTS, It changes duration, lift and lobe centers it is superior to BMW's Vanos even the advanced stepless vanos, Nissans CVTC, Mercedes, and Toyotas system that simply change the cam's lobe centers usualy only on the intake cam.

Now Honda does make crappy versions of vtec that only control the intake cam found on the latest D16 and D17 variants and the K20A found on the Base RSX. This crappy system is as good or better than what most of the other OEM's offer. The I-vtec system found on the RSX Type-S K20A2 is perhaps the most advanced variable cam timing system found in the automotive market, it can vary the lift, duration and the lobe center continuously.

VTEC gives the advantage of a mild cam at low rpm switching to a near race cam profile at high rpm. No other system ecept Nissan and Toyota's copys are even close in performance potential.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> I run 15 psi with no IC. One good rule of thumb is no long distance boosting on the highway , the intake can heat up pretty dramatically , and engine knock can blow your headgaskets....... But for around town and just general ricer spanking , 13-14 psi is quite adequate. 14 psi is the supposed limit of the fuel system's capacity , but I ran 15 psi for a long time with no issues.


On pump gas, I personaly would not go past 12-14 psi on a Z31. You live at hgih altitude and might be able to get away with more due to the low air density of where you live.

I don't know anything about the L28ET, I am not sure what the injector size is on it to esitmate what the highest stock safe boost might be. I'd say that 12 psi is proably perfectly safe and to determine what is really safe would require a wide band o2 sensor, you want to run an A/F ratio 11-11.5:1 or so on pump gas.

Adding a junkyard starion intercooler, exhaust and a boost dependednt fuel pressure regulator will make a big difference with some tweaking.


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> On pump gas, I personaly would not go past 12-14 psi on a Z31. You live at hgih altitude and might be able to get away with more due to the low air density of where you live.
> 
> I don't know anything about the L28ET, I am not sure what the injector size is on it to esitmate what the highest stock safe boost might be. I'd say that 12 psi is proably perfectly safe and to determine what is really safe would require a wide band o2 sensor, you want to run an A/F ratio 11-11.5:1 or so on pump gas.
> 
> Adding a junkyard starion intercooler, exhaust and a boost dependednt fuel pressure regulator will make a big difference with some tweaking.


I wonder if a Starion IC would be big enough , I was considering more like a Supra TT IC.


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Honda's vtec is one of the best variable cam timing systems avalible. Nissans VVL system is nearly a direct copy of it as is Toyota's system used in the Celica GTS, It changes duration, lift and lobe centers it is superior to BMW's Vanos even the advanced stepless vanos, Nissans CVTC, Mercedes, and Toyotas system that simply change the cam's lobe centers usualy only on the intake cam.
> 
> Now Honda does make crappy versions of vtec that only control the intake cam found on the latest D16 and D17 variants and the K20A found on the Base RSX. This crappy system is as good or better than what most of the other OEM's offer. The I-vtec system found on the RSX Type-S K20A2 is perhaps the most advanced variable cam timing system found in the automotive market, it can vary the lift, duration and the lobe center continuously.
> 
> VTEC gives the advantage of a mild cam at low rpm switching to a near race cam profile at high rpm. No other system ecept Nissan and Toyota's copys are even close in performance potential.


 I think most of the derision involved with V-tec is how much the ricers overrate it. They think it's the greatest thing ever , even better than a turbo........  V-tec _is_ a good system , one of the best ever. A lot of it's fame came from being showcased on the early model NSXs , I know of instructors in automotive classes that _still_ rave about how advanced V-tec is.........


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## morepower2 (Apr 19, 2002)

[email protected] said:


> I wonder if a Starion IC would be big enough , I was considering more like a Supra TT IC.


Just thinking a starion would be cheaper and more plentiful in junkyards.


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## chimmike (Oct 17, 2002)

[email protected] said:


> I think most of the derision involved with V-tec is how much the ricers overrate it. They think it's the greatest thing ever , even better than a turbo........  V-tec _is_ a good system , one of the best ever. A lot of it's fame came from being showcased on the early model NSXs , I know of instructors in automotive classes that _still_ rave about how advanced V-tec is.........



hate to bring it up, but isn't BMW's doube-vanos system better than all? I remember an article by Coleman in SCC last year where he talked about the double vanos and how it was better.


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## Zen31ZR (Mar 24, 2004)

chimmike said:


> hate to bring it up, but isn't BMW's doube-vanos system better than all? I remember an article by Coleman in SCC last year where he talked about the double vanos and how it was better.


 I was personally thinking that VVTLi was the best of all. And Porsche uses a variant too , not sure what it's name is.........


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## Zen31ZR (Mar 24, 2004)

chimmike said:


> hate to bring it up, but isn't BMW's doube-vanos system better than all? I remember an article by Coleman in SCC last year where he talked about the double vanos and how it was better.


 And don't get me started on Coleman again....................


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## morepower2 (Apr 19, 2002)

chimmike said:


> hate to bring it up, but isn't BMW's doube-vanos system better than all? I remember an article by Coleman in SCC last year where he talked about the double vanos and how it was better.


Double vanos moves the cam follower fulcrum and it can't get the same valve events VTEC can as far as making hp. For pumping loss reduction its better but not power production.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> I was personally thinking that VVTLi was the best of all. And Porsche uses a variant too , not sure what it's name is.........


The vvti system used in the celica GTS is nearly identical to VTEC. The VVTI system used in Lexus only changes the intake cam lobe center, its almost identical to Nissans VVL system. This is inferior to VTEC.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> And don't get me started on Coleman again....................


If you really think he can't drive you ought to meet him and go for a ride with him, odds are he'll make you crap in your pants.

I am a relativly sucessfull race driver and he can smoke me in fine car control. He can get used to a car so fast. I can only match him if I am very used to a car and corner.

I was with him last week and he drifted almost all the way around a 270 degree freeway onramp in a bone stock GA16 B13 sentra! A sustained drift. This is because he wanted to show me it was posible. He didnt practice or anything, it was like "hey check this out" picking the onramp at random after he was telling me that you could drift this car. This was an onramp with big curbs and a steel guardrail.

Entering the turn way too fast, I asked him if he was sure he knew what he was doing because I didnt think we were going to make it. He laughed, left foot braked it to get it sideways and did a smooth slide almost all the way around balancing it with the throttle.

Dave can outdrive many pro race car drivers and out drift all but the best pro drifters and he doesnt even practice drifting.


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## das280zx (Jul 17, 2003)

Cool, you know Dave Coleman! I met him once at a rally. He must be able to drive well because he placed very well when he raced the 510 beater rally car. I think to be a really good race driver, you have to be almost fearless. That is one of my problems. I am always afraid of breaking something.


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## Marc Z31 (Jul 25, 2004)

morepower2 said:


> The vvti system used in the celica GTS is nearly identical to VTEC. The VVTI system used in Lexus only changes the intake cam lobe center, its almost identical to Nissans VVL system. This is inferior to VTEC.


Honda's V-tec system is inferior to EVERY other car company. They really were behind until the I-vtec came out. the I-vtec is like every body else's systems that have been out for years and years. People think V-tec is better because you can FEEL it change, but everyone else's changes smoothly and efficiently. This is really a re-post, but v-tec really sucks compaired to everyone else's systems. Porshe and BMW DO have the best systems out right now. Honda ripped V-tec off of porshe anyway. At the time, it was better, but now it sucks.


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## morepower2 (Apr 19, 2002)

Marc Z31 said:


> Honda's V-tec system is inferior to EVERY other car company. They really were behind until the I-vtec came out. the I-vtec is like every body else's systems that have been out for years and years. People think V-tec is better because you can FEEL it change, but everyone else's changes smoothly and efficiently. This is really a re-post, but v-tec really sucks compaired to everyone else's systems. Porshe and BMW DO have the best systems out right now. Honda ripped V-tec off of porshe anyway. At the time, it was better, but now it sucks.


Tell me why its inferior using quantitive data. The Nissan VVL and Toyota VVTI as in the clelica GTS are almost direct copies. The Nissan VTC and CVTC, Toyota VVT, and BMW Vanos simply control only the lobe center of the cams which has limited control of the engines power charicteristics. BMW's new Vanos in one model moves the cam follower fulcrum so they can control lift and duration infinatly in a limited range so they can eliminate the throttle and pumping loss. They cannot run a real radical profile with lots of area under the curve at the full area postion.

VTEC can be felt because it is making a huge difference. Its switching from a small cam which has best low end torque, best fuel economy, low emmissions, smooth idle and good low speed driveablitly to a near full race cam at high rpm. The high rpm lobe has around 290 degrees of duration and about .490" lift. Thats more duration than a JWT C3 cam for instance. When the high rpm lobes are activated the power increse is huge, hence the jump you feel and hear.

The the other systems simply retard the intake cam at idle and low speeds to reduce overlap for low HC emmisions and idle smoothness, then advance the cam at mid rpm to improve midrange, then retard the intake cam at high rpm for better top end.

IVTEC is like combining VTEC with VTC, the engine also varies the phasing of the intake cam as well as having a high and low speed cam lobe.

BMW's advanced Vanos is like almost no cam at low rpm and a normal stock cam at high rpm.

The difference is that the other systems are like having an adjustable timing gear only on the intake which gives limited results, vs having a system that automaticaly kicks in a full race cam when you need it.

How is that inferior in any way? Even old VTEC gives more power with a smoother idle and better low speed capabilty than any other system other than the idential Nissan VVL and Toyota VVTI. IVTEC is even better.

No mass production engines can match the power per liter NA of honda engines. Having tuned Honda engines, I can say with confidence that a B seires and K series motor will kill an SR20 or any other nissan 4 banger NA any day. How is that inferior?


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## myoung (Apr 15, 2002)

wow Mike.. step away from the coffee 

Sounds like you wrote a book on it.... oh yea you did....lol


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> If you really think he can't drive you ought to meet him and go for a ride with him, odds are he'll make you crap in your pants.
> 
> I am a relativly sucessfull race driver and he can smoke me in fine car control. He can get used to a car so fast. I can only match him if I am very used to a car and corner.
> 
> ...


Not really so much that he can't drive , but that he makes an ass of himself in the Technobabble section of SCC. I don't want to start _that_ conversation again , it's just an opinion I've acquired over a number of years of reading SCC...... I suppose meeting the guy would be a lot different. You know him , I don't. so I can't really be an accurate judge of anything. None of us can. Untill you actually meet somebody , either him or any of us here , we are all just lines of words on a page........


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Tell me why its inferior using quantitive data. The Nissan VVL and Toyota VVTI as in the clelica GTS are almost direct copies. The Nissan VTC and CVTC, Toyota VVT, and BMW Vanos simply control only the lobe center of the cams which has limited control of the engines power charicteristics. BMW's new Vanos in one model moves the cam follower fulcrum so they can control lift and duration infinatly in a limited range so they can eliminate the throttle and pumping loss. They cannot run a real radical profile with lots of area under the curve at the full area postion.
> 
> VTEC can be felt because it is making a huge difference. Its switching from a small cam which has best low end torque, best fuel economy, low emmissions, smooth idle and good low speed driveablitly to a near full race cam at high rpm. The high rpm lobe has around 290 degrees of duration and about .490" lift. Thats more duration than a JWT C3 cam for instance. When the high rpm lobes are activated the power increse is huge, hence the jump you feel and hear.
> 
> ...


I had to import a smiley for this one......







and


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## hondakillerZX (Aug 16, 2004)

damn


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## ZUL8TR (Sep 2, 2004)

Personally I think VVT sucks in the first place. In my opinion its way too much of a crutch, or bandage to fix a problem that noone could engineer a better solution for.

How about DoD? General Motors has a fully functional (two, last I checked) line of cars in design with the DoD concept fully integrated and functional. The transition from economy and power is totally seemless and invisible to the user. Hot Rod magazine did a huge review on it a few months back (well, like eight to ten) in a full sized Chevy truck with the 6 liter V8, and a Malibu with the Series III 3800 both rigged with DoD.


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## Zen31ZR (Mar 24, 2004)

ZUL8TR said:


> Personally I think VVT sucks in the first place. In my opinion its way too much of a crutch, or bandage to fix a problem that noone could engineer a better solution for.
> 
> How about DoD? General Motors has a fully functional (two, last I checked) line of cars in design with the DoD concept fully integrated and functional. The transition from economy and power is totally seemless and invisible to the user. Hot Rod magazine did a huge review on it a few months back (well, like eight to ten) in a full sized Chevy truck with the 6 liter V8, and a Malibu with the Series III 3800 both rigged with DoD.


 Personally , I think Displacement on Demand is a crutch. GM is basically being forced to use it to make their huge displacement gas wasteful pushrod engines emissions compliant. They can't figure out the concept of efficient OHC engines , so they had to go this route instead.  Personally , I'll stick with my 19 yr old reliable OHC engine , and when a DOD malfunction puts most GM vehicles by the side of the road , I'll be motoring past them with a huge smile on my face. VVT is far superior to DOD , Variable Valve Timing and Lift responds directly to engine airflow requirements and makes quite seamless transitions. DOD simply reacts to whether you are cruising for a long distance on teh highway and suddenly decide to put your foot on the floor to pass the car ahead of you. Pretty lame , in my opinion.


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## das280zx (Jul 17, 2003)

actually, if you look at gm cars and trucks, they get pretty impressive gas-mileage numbers with those old pushrod engine. Chevy trucks are pretty well known as getting better gas mileage than most other trucks. The corvettes also get vert good hwy mileage.


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## James (Apr 29, 2002)

[email protected] said:


> Personally , I think Displacement on Demand is a crutch. GM is basically being forced to use it to make their huge displacement gas wasteful pushrod engines emissions compliant. They can't figure out the concept of efficient OHC engines , so they had to go this route instead.  Personally , I'll stick with my 19 yr old reliable OHC engine , and when a DOD malfunction puts most GM vehicles by the side of the road , I'll be motoring past them with a huge smile on my face. VVT is far superior to DOD , Variable Valve Timing and Lift responds directly to engine airflow requirements and makes quite seamless transitions. DOD simply reacts to whether you are cruising for a long distance on teh highway and suddenly decide to put your foot on the floor to pass the car ahead of you. Pretty lame , in my opinion.


ya, and when these cylinders are not firing, the pistons and rods and part of their crankshaft is still carrying mass and rotating...


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## ZUL8TR (Sep 2, 2004)

[email protected] said:


> Personally , I think Displacement on Demand is a crutch. GM is basically being forced to use it to make their huge displacement gas wasteful pushrod engines emissions compliant. They can't figure out the concept of efficient OHC engines , so they had to go this route instead.  Personally , I'll stick with my 19 yr old reliable OHC engine , and when a DOD malfunction puts most GM vehicles by the side of the road , I'll be motoring past them with a huge smile on my face. VVT is far superior to DOD , Variable Valve Timing and Lift responds directly to engine airflow requirements and makes quite seamless transitions. DOD simply reacts to whether you are cruising for a long distance on teh highway and suddenly decide to put your foot on the floor to pass the car ahead of you. Pretty lame , in my opinion.



Okay, well you're very much entitled to your opinion. My opinion is that they're going to make it work and it's going to rock. If they have sucess with the system we could very well see the Big Block muscle car come back, which is why I like it so much. I like HUGE and VERY powerful engine, I LOVE torque. Small rubber band econobox engines make no torque. Ya know what? The pushrod engine has worked for over 50 years now, and keeps getting better. I built a ZZ4 small block chevy thats all motor, cost me less than 4000$, gets 30mpg on the highway and makes well over 450rwhp and almost 500 foot pounds of torque. Call me old fashion, but I don't see any VTEC engines making that much, for a sililar price, and N/A. 

Before you reply please keep in mind, I'm not trying to start a huge pissing match between 4 bangers and V8s. Its played out and I'm not wanting to participate in that anymore myself. Several cars I drive are 4 cylinder powered; A 1990 240SX with a KA24E in it, a little parts fetching pickup with a Turbocharged 2.3 liter ford, etc. One other comment I might make, the car with the V8 gets better gas mileage in the city than my KA does, and the truck did before I built the turbocharged engine.

Personally I'd love to have a DOD equipped V8 with a 4340 crank, h-beam rods, and about an 8.5:1 compression forged set of pistons. Toss a pair of T60 turbos on that thing, or a huge T71 and watch the fun begin. Not only would it pass emissions tests in california, but it would likely make some upper tripple digit numbers, and get 40mpg on the highway. Thats what I care about anyway. :cheers:


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## James (Apr 29, 2002)

ZUL8TR said:


> Personally I'd love to have a DOD equipped V8 with a 4340 crank, h-beam rods, and about an 8.5:1 compression forged set of pistons. Toss a pair of T60 turbos on that thing, or a huge T71 and watch the fun begin. Not only would it pass emissions tests in california, but it would likely make some upper tripple digit numbers, and get 40mpg on the highway. Thats what I care about anyway. :cheers:


no beef on anything else except, that would NOT pass emissions in CA...


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## Zen31ZR (Mar 24, 2004)

das280zx said:


> actually, if you look at gm cars and trucks, they get pretty impressive gas-mileage numbers with those old pushrod engine. Chevy trucks are pretty well known as getting better gas mileage than most other trucks. The corvettes also get vert good hwy mileage.


 Yep exactly. _Highway mileage_. Strap a big hulking torque motor massing 5.7 and up liters to a set of 2:56 gears and a 6 spd tranny with a .65 overdrive ratio , and you better get good highway mileage. I'd be pissed if I didn't. But I'll bet pound for pound my 3.0 V6 gets better fuel mileage at 4000 rpm on the highway than any V8 ever will.


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## Zen31ZR (Mar 24, 2004)

ZUL8TR said:


> Okay, well you're very much entitled to your opinion. My opinion is that they're going to make it work and it's going to rock. If they have sucess with the system we could very well see the Big Block muscle car come back, which is why I like it so much. I like HUGE and VERY powerful engine, I LOVE torque. Small rubber band econobox engines make no torque.


VTEC engines don't make torque , aren't supposed to. Those are high rpm engines , which generally precludes any sort of reasonable torque band til you get half way around the tach. Torque is not the point of that engine , that engine was designed to run sustained high rpms. B16s and 18s can run well over 9000 rpm for extended periods of time , and if built properly can do the same at over 11,000 rpm.
Now the VG30 , on the other hand , don't tell me that engine does not make torque. The factory numbers will tell you that. 200 Hp , 220+ pounds of torque. Not too many small cube engines boast more torque than Hp. Add a little boost and torque goes nuts. You'll hit 500 lb/ft of torque long before you'll hit 500 Hp , with these engines. I like torque too , trust me , I was poking around under the hoods of big V8s long before a lot of you guys were out of diapers , but I like the sound and feel of a high rpm engine pulling me toward redline.....


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## hondakillerZX (Aug 16, 2004)

wat kind of system do the vg30et's have


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> What kind of system do the VG30ET's have.


 Not sure what you mean by that. If you mean type of cam system , it's just a single overhead cam (per head). This is old tech , mid-80's cars like this didn't have much besides sequential injection. Unless of course you want to buy a Ferrari or a Porsche........


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## morepower2 (Apr 19, 2002)

ZUL8TR said:


> Personally I think VVT sucks in the first place. In my opinion its way too much of a crutch, or bandage to fix a problem that noone could engineer a better solution for.
> 
> How about DoD? General Motors has a fully functional (two, last I checked) line of cars in design with the DoD concept fully integrated and functional. The transition from economy and power is totally seemless and invisible to the user. Hot Rod magazine did a huge review on it a few months back (well, like eight to ten) in a full sized Chevy truck with the 6 liter V8, and a Malibu with the Series III 3800 both rigged with DoD.


DOD sucks, high frictional losses and poor thermal effiecnecy for the deactivated cylinders always have cold quench issues when being brought back online.


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## morepower2 (Apr 19, 2002)

ZUL8TR said:


> Okay, well you're very much entitled to your opinion. My opinion is that they're going to make it work and it's going to rock. If they have sucess with the system we could very well see the Big Block muscle car come back, which is why I like it so much. I like HUGE and VERY powerful engine, I LOVE torque. Small rubber band econobox engines make no torque. Ya know what? The pushrod engine has worked for over 50 years now, and keeps getting better. I built a ZZ4 small block chevy thats all motor, cost me less than 4000$, gets 30mpg on the highway and makes well over 450rwhp and almost 500 foot pounds of torque. Call me old fashion, but I don't see any VTEC engines making that much, for a sililar price, and N/A. :


Dunno, my turbo SE-R makes 320 lb/ft of torque. My 300ZX makes 549 lb/ft of torque. Small engines can make lots of torque.


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> DOD sucks, high frictional losses and poor thermal effiecnecy for the deactivated cylinders always have cold quench issues when being brought back online.


 Seems to me Cadillac had such a system in the 80's with the 4/6/8 engine , which also deactivated sets of cylinders depending on throttle position and length of time at cruising speeds. Seems to me that system did not do very well either in practice nor dependability and was scrapped in favor of the Northstar project.


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## Marc Z31 (Jul 25, 2004)

I still think Vtec sucks. I am a member of SAE and am currently a student in mechanical engineering. The SAE meetings I attend are hosted by automotive engineers, and the guys from toyota, GM, ford, and nissan all have told me the same thing. Vtec was great, when it came out. It was a porshe system that had been made better and more reliable. Now, it is out dated and inefficient. Those thousand RPMs before the system kicks in are not making as much power as possible. To make the most power possible, the system would have to have several thousand sets of changes that would occor rapidly one after another. The same cam does not make the maximum power at different RPM's. If the valves were continuously changing, then maximum volumetric efficiency could be achieved. The systems that have NO cams are the most superior. Solenoids controlling valves would be the best means of variable valve timing. There would be an infinite amount of ajustability and the valves are not limited by cam lobe angles. They could open faster and close faster. We should be seeing some systems like these in the next few years from caddilac and other GM vehicles. 

BTW, the fastest car I have ever ridden in got an average of 30 MPG (45 HWY), and had pushrods. Twin turbo C4 corvette-1200+rwhp (pegged the dyno) Don't talk trash about pushrods if you can't beat them.


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## morepower2 (Apr 19, 2002)

Marc Z31 said:


> I still think Vtec sucks. I am a member of SAE and am currently a student in mechanical engineering. The SAE meetings I attend are hosted by automotive engineers, and the guys from toyota, GM, ford, and nissan all have told me the same thing. Vtec was great, when it came out. It was a porshe system that had been made better and more reliable. Now, it is out dated and inefficient. Those thousand RPMs before the system kicks in are not making as much power as possible. To make the most power possible, the system would have to have several thousand sets of changes that would occor rapidly one after another. The same cam does not make the maximum power at different RPM's. If the valves were continuously changing, then maximum volumetric efficiency could be achieved. The systems that have NO cams are the most superior. Solenoids controlling valves would be the best means of variable valve timing. There would be an infinite amount of ajustability and the valves are not limited by cam lobe angles. They could open faster and close faster. We should be seeing some systems like these in the next few years from caddilac and other GM vehicles.
> 
> BTW, the fastest car I have ever ridden in got an average of 30 MPG (45 HWY), and had pushrods. Twin turbo C4 corvette-1200+rwhp (pegged the dyno) Don't talk trash about pushrods if you can't beat them.


Well I am an automotive engineer for a major OEM working for their high perfomance OES department. Its not Honda but I am envious of their systerm having had expericance with it.

I bet the vette dosent make an average of 30 mpg city/hwy. Its probably data provided by the owner who is exagerating. Low compression turbo V8 has a poor BSFC off boost. A SBC has an obsolete combustion chamber design which doesnt lend itself to high BSFC's either unless he has some of the latest heads with canted valves, low surface to volume ratios and lots of quench, which means only a few NASCAR aftermarket heads.

No real automotive engineer would say that the Honda VTEC systems are obsolete. I don't even think you fully understand the mechanics and the control systems of the variable cam timing systems on the market. I don't think you have any real experiance tuning motors either. If you did you would not come to that conclusion.

The infinatly variable cam timing system you are talking about is vaporware. If it exsisted it would be the ultimate in varibable cam timing but it does not. The technology for it does not exisit for production motors. Engines with these systems only run in labs. Those that do can't manage at rpm over 5000, the solenoids don't respond fast enough to give more area under the curve than a cam will. The power consumed by the actuators is greater than the gain created by incresed VE and reduced pumping losses. It will be several years before these sorts of systems are production ready and since the industry is rejecting the proposed SAE 42 volt standard, it may not happen for even a longer period.

Where is your supporting data showing that VTEC is inferior to current production OEM varible cam timing systems? There is much published showing that it isnt. If you want to have much of a future as an engineer, you should not make bold statments unless you have quantitative data to support your statements.


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