# Redline question



## jbnismo (Jun 4, 2005)

Wats the redline on a b15 sentra the one with a Sr20 motor.. and can i use jdm sr20 parts and performance parts made for the RWD on a FWD??


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## chimmike (Oct 17, 2002)

redline on your engine is 6750, and no you can't use those parts.


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## sarsourus (Apr 8, 2005)

chimmike said:


> redline on your engine is 6750, and no you can't use those parts.


i was wondering, if jwt cracked the ecu, is it possible that we can get some horses outta there or a longer redline, because to think about it, they can reprogram the butterfly valves to open longer ad higher the redline?

isn't it possibly? i mean if the ecu was cracked in to it....


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## jbnismo (Jun 4, 2005)

wouldnt a camshaft or camgears make for a longer redline?


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## chimmike (Oct 17, 2002)

jbnismo said:


> wouldnt a camshaft or camgears make for a longer redline?



no. redline is controlled by ecu. what do you need a higher redline for? You need to learn to use what you have....


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## sarsourus (Apr 8, 2005)

chimmike said:


> no. redline is controlled by ecu. what do you need a higher redline for? You need to learn to use what you have....


but i mean if the ecu could be cracked in to and made the redline longer and butterfly vavlves open longer than i guess it would be more horsepower and i guess accelleration?, but what i mean is that you can take first gear longer and second gear too, by the time u reach 3rd gear you toped 80 and still going. it will make the car faster..

is it possible?


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## chimmike (Oct 17, 2002)

sar, he's not talking about your engine, he's talking about a totally different engine.

there will be no jwt ecu for the QR, so I would stop alluding to that if I were you.


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## sarsourus (Apr 8, 2005)

chimmike said:


> sar, he's not talking about your engine, he's talking about a totally different engine.
> 
> there will be no jwt ecu for the QR, so I would stop alluding to that if I were you.


but why weren't there be one? u mean jwt can't do it or its not worth doing one for it meaning no use?


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## pete? (Jul 6, 2004)

why do people have a boner for high red lines? the red line is determined by the engine....the ecu cut off is put there for safety. unless you have internal engine work it is not wise to raise your red line, the QR motor would shatter at high red lines because of the long stroke.

indy cars and sport bikes rev like crazy because of there extremely long throw, at the cost of TQ, but because they are insainly light, they can afford this. just because you can rev higher has absolutely nothing to do with having more power.


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## sarsourus (Apr 8, 2005)

pete? said:


> why do people have a boner for high red lines? the red line is determined by the engine....the ecu cut off is put there for safety. unless you have internal engine work it is not wise to raise your red line, the QR motor would shatter at high red lines because of the long stroke.
> 
> indy cars and sport bikes rev like crazy because of there extremely long throw, at the cost of TQ, but because they are insainly light, they can afford this. just because you can rev higher has absolutely nothing to do with having more power.


An answer well put..
thanx


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## pete? (Jul 6, 2004)

pete? said:


> indy cars and sport bikes rev like crazy because of there extremely *SHORT* stroke, at the cost of TQ, but because they are insainly light, they can afford this. just because you can rev higher has absolutely nothing to do with having more power.


just an FYI. i just cought a massive bluper i made. indy cars and sport bikes have a very *short stroke*, not long.
:balls: stupid pete and his fast typing


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## Loki (Jan 12, 2004)

chimmike said:



> redline on your engine is 6750, and no you can't use those parts.



My friend has a 93 Tsuru GSR2000 with the SR20DE and it redlines at 7500.. why is there a difference?


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## pete? (Jul 6, 2004)

he had a 93.........you have a 2000.......need i say more? do a search and find out the differances in the motors.


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## chimmike (Oct 17, 2002)

Loki said:


> My friend has a 93 Tsuru GSR2000 with the SR20DE and it redlines at 7500.. why is there a difference?


because it's a different SR20.


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## Loki (Jan 12, 2004)

chimmike said:


> because it's a different SR20.



so the GSR2000 SR20 is better? or what? it even says 40th aniversary on the valve cover.....


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## chimmike (Oct 17, 2002)

Loki said:


> so the GSR2000 SR20 is better? or what? it even says 40th aniversary on the valve cover.....


that "40th anniversary" crap was put there by your friend or whoever. 

neither one is any better, there are merely changes in the valvetrain and slight changes in the internals. The main differences are aftermarket support also.


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## Loki (Jan 12, 2004)

chimmike said:


> that "40th anniversary" crap was put there by your friend or whoever.
> 
> neither one is any better, there are merely changes in the valvetrain and slight changes in the internals. The main differences are aftermarket support also.



I will just take pic's of the car and engine and show them to you... I think you dont even know what a Tsuru GSR2000 is...


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## ReVerm (Jan 13, 2003)

Loki said:


> I will just take pic's of the car and engine and show them to you... I think you dont even know what a Tsuru GSR2000 is...


I think the reason Chimmike is suspicious is because Nissan/DATsun first set foot in Mexico in 1961. It didn't actually start selling cars in Mexico until 1966 (the first car sold in Mexico was a Bluebird sedan. The Sunny/Sentra series appeared later). 

Now, if your friend's car is a 1993 model, what would that "40th anniversary" emblem on the vavle cover refer to? The 40th anniversary of Nissan Mexicana's founding would be 1991, and the 40th anniversary of the first Sunny would be late 90's (1996 if they were on the same schedule as everywhere else). It certainly isn't the 40th anniversary of the SR series, as that didn't appear til the 80's. I'm not saying that it didn't come like that from the factory. I'm just curious about what that's talking about.

In any case, blindly raising the redline on any engine is not a very good idea. The first reason has to do with the order in which certain aspects of gasoline engines are designed. Most engine manufacturers will first tune the engine to produce the necessary output and reliability, then decide on where the rev limiter should kick in. Because Nissan's engineers (unlike GM and Audi's engineers, who sometimes do bizzare things that I don't understand) understand that it's best (for the driver) to have the engine produce peak output slightly before redline, there's actually a sharp dropoff right near the rev limiter. If you just blindly raise the rev limiter through the ECU without adjusting timing or lift, that power curve is just going to keep going down. You'll end up with an engine that revs really high but produces very little power.

The second reason is that SR20s don't like being over-revved. It's pretty common to see people accidentally downshift at the wrong time and peg 9000 rpms, only to witness the rocker arms drop and the engine blow. If you raise the redline, you are actually increasing the chances that a missed shift will destroy your engine.


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## chimmike (Oct 17, 2002)

Loki said:


> I will just take pic's of the car and engine and show them to you... I think you dont even know what a Tsuru GSR2000 is...



a Tsuru is a mexican b13...and that particular model has an SR20. it's essentially a B13 SE-R. And don't waste your time taking pics, I simply don't care.

What the hell is your point anyways? That SR20 is no different than the SR in the b13 SE-R, and no better than the roller-rocker SR20 in the b15.


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## Loki (Jan 12, 2004)

chimmike said:


> a Tsuru is a mexican b13...and that particular model has an SR20. it's essentially a B13 SE-R. And don't waste your time taking pics, I simply don't care.
> 
> What the hell is your point anyways? That SR20 is no different than the SR in the b13 SE-R, and no better than the roller-rocker SR20 in the b15.


dont worry i wont post pics for yourself alone....just cuss i want to thats all  shit its not my fault it says that shit and that it revs 7500...


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## chimmike (Oct 17, 2002)

WHAT THE HELL IS YOUR POINT? Just because it revs to 7500 doesn't make it better 

the roller rocker SR20 is rate at [email protected], 5 more than the 91-99 SR's.......it doesn't rev as high ONLY BECAUSE OF A DIFFERENT VALVETRAIN. So in essence, it's BETTER because it doesn't need 750 more rpm to make that power, it makes MORE power with slightly less rpm to fool with.

anyways, I'm still waiting for your point. What is it? Only that you think it's better because it revs higher?


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## asleepz (Feb 24, 2004)

Everyone knows if you can pop out 10,000RPMs you instantly get 50 more WHP


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## Loki (Jan 12, 2004)

chimmike said:


> WHAT THE HELL IS YOUR POINT? Just because it revs to 7500 doesn't make it better
> 
> the roller rocker SR20 is rate at [email protected], 5 more than the 91-99 SR's.......it doesn't rev as high ONLY BECAUSE OF A DIFFERENT VALVETRAIN. So in essence, it's BETTER because it doesn't need 750 more rpm to make that power, it makes MORE power with slightly less rpm to fool with.
> 
> anyways, I'm still waiting for your point. What is it? Only that you think it's better because it revs higher?


My point is just to piss you off by posting the pics thats all....dont get all grumpy!  

I really dont care how much it revs....i still always beat the crap out of it...but its the fastest 2.0 around cuss its so damm light...well except for the renault clio sports here....


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## T200Sx (Jan 17, 2005)

:wtf: who cares my buddy has a 1969 chevelle that makes more horsepower than any car on this forums and it dont rev that high...who cares how high a car revs its about power and even more the driver...


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## ReVerm (Jan 13, 2003)

T200Sx said:


> :wtf: who cares my buddy has a 1969 chevelle that makes more horsepower than any car on this forums and it dont rev that high...who cares how high a car revs its about power and even more the driver...


That isn't entirely true. In some cases, it isn't about power, or the driver. Sometimes it really _is_ about being able to rev high.

Even though a lot of people associate high revving engines with peaky output (like in the case of the Honda F and B series powerplants), there is an inherent advantage to having a relatively high redline. Engines that can rev high from the factory are much easier to tune for a nice usable powerband. Just look at all those EG series Civics that used to compete in the Group A touring car series. The only real advantage they had was a super wide powerband (thanks to a modified B series block that could handle 12,500 RPM), and they still held their own in a grid full of BMWs and turbo Primeras. And the competition sometimes had 100 ps (~98 bhp) of peak output on these Civics.

Around a road course, through a rally stage, or during an autocross, a wide powerband matters much more than peak power. No matter how good the driver is and no matter how quickly he/she can shift, there are times when there is just no way to make up for not being able to rev that extra 1000 rpms. 

I'm still against people blindly increasing the redline on any production engine. It's pointless and most of the time, fruitless. However, I still think it's important for people to realize that having a low revving engine that produces a lot of peak power isn't a good thing either. It's not all about one thing or another. You have to consider everything.


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## zellx2004 (Sep 30, 2004)

If you want to rev high, just get a honda, and don't waste nissan engines. They're getting hard to come by. Thanks.


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