# What's up with today's engines?



## Greg200SE-R (Feb 5, 2003)

Is Honda the only one making high-revving engines nowdays? Will other makers learn that the way to get better horsepower numbers is to raise the redline and tune accordingly... If Honda's K-series were limited to 6500rpm like most other 4-bangers, their horsepower, tq and hp/liter numbers would be nothing special. That extra 1,500 rpm (Ok Ok - and VTEC) gives it such great numbers.

Since a car's hp curve is basically the torque curve angled at an uphill, raising the redline allows the hp curve to climb further before being cut off, correct? So allowing an engine's torque curve to stay flat and continue into higher RPMs would automatically raise the PEAK hp numbers.

But, instead of rasing redlines and therefore requiring the engine to be built stronger, everyone is making engines lighter, weaker, and increasing displacement instead. Just think if the QR25 were tuned to go up to, say, 7500 RPM reliably. It would hit 200+ too. But 2.5 liters is getting too large to design a "squarish" cylinder for, so 6500 RPM approaches the physical limit.

Maybe I'm used to such a balanced hp/tq curve of the SR20, but I like the philosophy of getting the most out of a smaller engine. Subaru and Mitsu make engines that go up to 7000rpm (turbocharged too) so why don't we see more NA engines hit 7000+? With today's technology they would all get 160+hp from 2 liters and be faster than the numbers on paper might imply.

Sorry so long. I tend to ramble in order to get all my ideas out.


----------



## James (Apr 29, 2002)

RX8


----------



## Slayer2003 (Jun 4, 2003)

3 main reasons.

Cost
Regulations
Economy


----------



## James (Apr 29, 2002)

oh and just because you raise the redline doesn't mean the engine will continue to make HP that high.


----------



## Nico Flax (May 3, 2003)

And anyway who really cares about HP at those high revs, what we need is some more displacement and some nice fat tq curves at the bottom end, I love the sound of those old V8s, god tire spinning fun.


----------



## niky (Jul 20, 2002)

Actually, there's a charm to screamers... it's sweet shifting high up there... makes it more of a game... plus you use less gas at low revs... love the dual personality that honda-style engines have... the SR20 was kinda like that, too.


----------



## myoung (Apr 15, 2002)

niky said:


> Actually, there's a charm to screamers... it's sweet shifting high up there... makes it more of a game... plus you use less gas at low revs... love the dual personality that honda-style engines have... the SR20 was kinda like that, too.


 they are torque is weak... 

Old but true quote: Horsepower Sells Cars, Torque Wins Races... 

now check the torque on those Hondas and compare it to the same size Nissan motors.. 




> Civic SI
> Mods: AEM Cold Air intake, DC Sports 4-2-1 header,
> Neuspeed 8mm plug wires, and Mugen twin loop muffler.
> Peak WHP: 148.1 Peak TQ: 103.9
> ...


Weak torque..


----------



## Harris (Nov 11, 2002)

Look up SR16VE N1 (Nissan motor). That should keep you happy for a while.


----------



## niky (Jul 20, 2002)

myoung said:


> Old but true quote: Horsepower Sells Cars, Torque Wins Races...


Ah... but I bought my current car because of torque... ... it's got the best torque curve of any new compact sold in my country. 

Actually, I was equating the SR20DE to the Honda engines in character and feel as compared to domestics... sure, it has more torque than the Honda, but that torque curve starts high also... the thing would give me a kick in the pants at 4000+rpm when I drove with it, but it was still docile at low revs...

...with the added bonus of in-traffic driveability versus a honda.   

C'mon, don't tell me you'd give up your 7k rpm redline for a torque-ier engine... 

On the other hand, my Mazda 2.0 now has a more equal balance of torque (more than the SR) and horsepower (a little less)... it doesn't have the top end of either the Honda or the Nissan, and makes most of its power a little lower in the rpm range... it feels more balanced, yes, but I wish I still had my SR... it was a screamer compared to this one.  (saving up for mazdaspeed parts, yo...) 

BTW: a case in point for HP versus torque would be the Corolla XRS... WTF were they thinking!? Toyota's VVTL seems to come out worse on the torque end than Honda's new VTECs... ???

I'd still like my car to scream a little more on the high end, though... just for purely personal satisfaction, mind you...


----------



## James (Apr 29, 2002)

myoung said:


> they are torque is weak...
> 
> Old but true quote: Horsepower Sells Cars, Torque Wins Races...
> 
> ...


i don't buy it.... race the two cars a B16 versus a GA16DE and see who wins... 

I had a 'runin' with a hatchback with some sort of JDM engine swap (NA) about a month ago. It may have no torque but that thing was fast...


----------



## niky (Jul 20, 2002)

stock B16 versus stock SR20 would be the more even match... the GA16 is an economy motor... 

Case in point, SR20 leads at the beginning, B16 wins out in the end... but translated to road racing on a track, that would give more advantage to the SR20 on twisty tracks (spend more time at lower speeds)... GIVEN that both cars weigh about the same. 

I've driven B16 hatches... they may be fast, but you've got to work DAMN hard to get them up there.


----------



## niky (Jul 20, 2002)

whoops, didn't notice it was you, James!

hiya! NO STREET RACING!!! lol...

how's your tranny holding?


----------



## James (Apr 29, 2002)

wasn't racing...  

why do you have to compare the sr20 to the b16? Naturally aspirated 1.6L's compared to each other... ok so sr16ve to b16... its not like either one of them has huge amounts of torque... and they both rev sky high... hp is a mathematical calculation of tq...


----------



## niky (Jul 20, 2002)

wasn't accusing... 

just comparing them because the difference in torque and the difference in hp come out to a near equal percentage... (13-14% difference stock, both ways) it's an interesting study... hehe...

if the discussion is hp vs. tq, that's about as close as you can get to evenly matched.


----------



## myoung (Apr 15, 2002)

niky said:


> C'mon, don't tell me you'd give up your 7k rpm redline for a torque-ier engine...
> 
> On the other hand, my Mazda 2.0


actually it's above 7000rp, thanks to JWT... 

hey I didn't dog the Mazda.. I like some of their new models...

Was mainly referring to Hondas.


----------



## myoung (Apr 15, 2002)

James said:


> i don't buy it.... race the two cars a B16 versus a GA16DE and see who wins...
> 
> I had a 'runin' with a hatchback with some sort of JDM engine swap (NA) about a month ago. It may have no torque but that thing was fast...


That quote comes from Caroll Selby..

If it had some sort of JDM swap then how would you know what it was or what was in it?

okay close to street racing topic and you know that's a no no...

was this run in for a dead start or were you already rolling? 

The B16 is a damn good motor.. you probably came up against something like this: http://www.honda-tech.com/zerothread?id=956178 check the mods and still only 120 tq... the GA16 is close to 100 tq with just a couple mods... remember back to the baseline dynos.. we had as much torque as HP...lol.. http://www.nissanperformancemag.com/may01/images/baseline2.jpg


----------



## myoung (Apr 15, 2002)

Harris said:


> Look up SR16VE N1 (Nissan motor). That should keep you happy for a while.


That would be a much better comparision to the JDM B16A than to a normal US GA16DE.


----------



## niky (Jul 20, 2002)

hehe... know you not trying to dog mah shitbox.   

SR16VE N1 would be a nice comparison, but unfair... we all know it's better.


----------



## nova73guy (Mar 30, 2004)

myoung said:


> hey I didn't dog the Mazda...



Okay, I'll dog 'em for ya. I used to work for a dealership that sold Mazdas. I was a mechanic on the Chev. side, and all the Mazda techs did was complain about how much they sucked. Of course EVERY Mazda I've personally test driven seemed WAY underpowered. Just my opinion. Oh, and I spanked a Mazda6 in my STOCK '98 SE-R last night.


----------



## James (Apr 29, 2002)

myoung said:


> That quote comes from Caroll Selby..
> 
> If it had some sort of JDM swap then how would you know what it was or what was in it?
> 
> ...


yeah i know where the quote comes from... 

as for the runin... i can pm you the details if you want.

i just think the super high rev high hp low tq motors (relative to their size I mean) have an advantage in races because how long they can hold each gear and still produce hp that high. it may suck driving on the street but in a race your engine isn't usually sitting at 3krpm...


----------



## bahearn (Jul 15, 2002)

Torque is directly proportional to displacement in naturally aspirated engines. Small engines make small torque.

As rpm goes up, friction goes up exponentially. Stress also rises exponentially.

Internal combustion engines are just air pumps. You either have to make them bigger or spin them faster to get more throughput.

Daily drivers want big torque. This allows adequate acceleration with low rpm for best gas mileage. Race engines want all possible power from rules-governed displacement that still maintains enough reliabilty to finish race.

If you REALLY want a screamimg engine, get a 600 cc Supersport motorcycle. They're using 15k redlines these days and putting out over 110 hp. Torque is limited to about 60 lb-ft, though, due to their small displacement.


----------



## Greg200SE-R (Feb 5, 2003)

Wow. didn't know my post would generate so much discussion. Interesting points. 

As much as I like an eninge with a fat torque curve and the "power on demand" at low RPMs, I know that same engine won't be able to hang with a similar-sized enigne that is tuned to pull up to much higher RPMs.

Remember it's not just the higher redline I was talking about, it's also the engine being tuned to take advantage of the top-end. Hondas are. Their PEAK torque numbers may not be so high, but at mid-to high RPMs the curves are flat and elongated, unlike most other makers whose torque curves peak well below redline and begin falling quickly approaching redline.

Bahearn is right; given the same enigne size, physics says they will all make similar torque numbers. I think of it as the "area below the curve." If you shade in the area below the torque curve on a dyno sheet, and compare this area between engines, they will all be similar. But, one maker might make a "fat" area in low RPMs, but in order to do that you must take away some of the area from a different part of the curve (the high end).

Honda makes lower torque numbers because they choose to make their curves longer (extned to higher RPMs) but this extra area from 6500 - 8000rpms means that there is less area for the low RPMs. Enter VTEC - this is what allows them to fill in some of the area both under the low RPMs as well as the top-end. Only variable valve LIFT and timing can make an engine with decent low end and still have a screaming top end. Variable intake runners and valve timing and stuff like that helps also, but are limited unless the enigne can generate two or more specialized torque bands (like VTEC, VEs and my future engine, BMWs Valvetronic)

One more thing: make an enigne rev to 8000 and you can gear the transmission shorter. All manual cars will top out 2nd gear just past 62mph (100kph) by second gear. A car with higher redline can have higher gear ratios and therefore increase torque through gearing.

For example at 2nd gear the RSX-S has a ratio of 2.13/1 while the (1998) SR20 has 2nd at 1.83/1. The ratios actually MULTIPLY torque numbers at a given RPM... so if at a certain RPM a KA20 engine makes 100lb/ft, in second gear the axle will actually see 213lb/ft (100*2.13). The SR20, while it may make 100ft/lb at a lower RPM, will only output 183lb/ft. In actuality it isn't that much of a difference but...

Higher redline/top-end tuning = shorter gears = greater multiplication of torque. Hondas have shorter gearing working for them, so add this with a screaming top end and you have cars that will chirp 1st, 2nd, 3rd and sometimes 4th gear... Naturally aspirated. 

I'm not a Honda lover, I am damn proud to drive a Nissan. But I think more manufacturers should consider their engine tuning philosophy more... but of course this is only for competition. On real world roads and stop and go traffic, the important rev band is from 1 - 5000. Most makers focus their engines on this band, which is perfect for 90% of the ppl out there. For those of us who want to compete in motorsports, we need more high-end oriented engines. Luckily, the SR20 manages a good balance between both extremes. 

Holy crap. I better get off the computer and do some work. Thanks for reading.


----------



## sethwas (Apr 30, 2002)

Greg200SE-R said:


> Is Honda the only one making high-revving engines nowdays? Will other makers learn that the way to get better horsepower numbers is to raise the redline and tune accordingly... If Honda's K-series were limited to 6500rpm like most other 4-bangers, their horsepower, tq and hp/liter numbers would be nothing special. That extra 1,500 rpm (Ok Ok - and VTEC) gives it such great numbers


Dunno, 
A 1.9 liter VW diesel naturally aspirated makes more power at idle than those honda's do at peak. (ok, maybe a little off idle, but it's still 179 ft/lbs)

Seth


----------



## James (Apr 29, 2002)

sethwas said:


> Dunno,
> A 1.9 liter VW diesel naturally aspirated makes more power at idle than those honda's do at peak. (ok, maybe a little off idle, but it's still 179 ft/lbs)
> 
> Seth



and a locomotive makes 3000ft lbs of torque at 50rpm... doesn't mean its going to win any races  :cheers:

as for me? i'm going to make as much torque at as high of an rpm as I can!


----------



## Greg200SE-R (Feb 5, 2003)

sethwas said:


> Dunno,
> A 1.9 liter VW diesel naturally aspirated makes more power at idle than those honda's do at peak. (ok, maybe a little off idle, but it's still 179 ft/lbs)
> 
> Seth


Haha, true. Diesels take the low-end torque curve to the extreme - very long stroke and very high compression. they generate a ton of low-end, but thats the same reason they redline about, what, 4500RPM? Isn't the 1.9 turbocharged tho?

Most (gas) engines nowdays have long-stroke undersquare, high-torque (and therefore low redline) engines... To most people these engines feel more powerful because they jump at low to mid rpms, but in competition it's all about the high-end.



James said:


> as for me? i'm going to make as much torque at as high of an rpm as I can!


that seems to be the way to go... But damn look at some of the project SE-Rs and look what needs to be done to keep that curve up at high RPMs. It seems that to be truly high-end oriented, and engine needs to be engineered for it from the beginning.


----------



## Harris (Nov 11, 2002)

Greg, dude, I told you to look up the SR16VE N1. Nissan *IS* doing exactly what you're talking about. 

To prove it, looky down:































Amazing, eh?


----------



## chimmike (Oct 17, 2002)

sethwas said:


> Dunno,
> A 1.9 liter VW diesel naturally aspirated makes more power at idle than those honda's do at peak. (ok, maybe a little off idle, but it's still 179 ft/lbs)
> 
> Seth



the 1.9 TDI is turbocharged, it's rated at 90hp and 150tq at the crank. My girl's folks have one in a beetle. Keep in mind a diesel engine is a totally different beast than a gas engine. 

Also the TDI has a 4000rpm redline or so...........and it's all torque, no horsepower....just like most diesel engines are.


James, your saying about high revving engines being able to stay in gear longer instead of having to shift.....that really has very little to do with high or low revving, it's all about gear ratios. You want to be able to stay in gears longer? get appropriate gears.............


----------



## James (Apr 29, 2002)

chimmike said:


> James, your saying about high revving engines being able to stay in gear longer instead of having to shift.....that really has very little to do with high or low revving, it's all about gear ratios. You want to be able to stay in gears longer? get appropriate gears.............


Don't you think it has to do with both?  Like said earlier, look at the Honda engines, they can afford to have better gearing because they're engines can rev so high.


----------



## niky (Jul 20, 2002)

LOL... OFFTOPIC, hey James, want some tranny loving? How about a GA13-GA15 tranny? Those trannies are SHORT compared to the GA16 tranny... closer ratio, better accel... but they'll still hit 120+ mph... and they are common as shit.


----------



## James (Apr 29, 2002)

they'll probably snap easy though... hey if you want to send one over... I'll give it a shot!


----------



## sethwas (Apr 30, 2002)

I don't see what RPM has to do with torque in racing. 
It's like Ferrari v. BMW in racing. The Ferrari can power out of corners better, but the BMW can beat it in the straightaway. It's just a matter of design.

If the engine makes more power, then it can be geared higher and still accellerate as a weaker engine with more RPM and gears. The spin to 4500RPM can take just as long as the spin to 7500RPM.
I'm talking stock. 
You change the injectors of the PD TDI's and you can get over 300ft/lbs of torque at a small expense in fuel mileage. The redline isn't moved much but it doesn't matter since the new power to weight is absurd. In racing, road racing, not drag, you have more power across the board. So passing and 20-50 or 70-90 becomes a joke.

The effect of turbo's on a diesel isn't the same as it is in a gasser. In a gasser the amount of air determines the amount of gas. In a diesel the amount of gas determines the amount of air. THis is why bigger injectors act like a turbo. THe turbo just pumps more air to catch up.

Seth


----------



## James (Apr 29, 2002)

> horsepower = rpm x torque / 5252
> 
> torque = 5252 x horsepower / rpm


http://www.nightrider.com/biketech/calc_formulas_page.htm

edit:

similar discussion at sr20forum:

http://www.sr20forum.com/showthread.php?t=35901


----------



## Greg200SE-R (Feb 5, 2003)

has anyone heard of Nissan's new 1.5 and 2.0 engines? They are supposedly designed to be mated with their new CVT trannys. There aren't too many specs on them out yet, but it sounds like they are continuing in the direction of low-end torque bands and away from the direction we all want them to go: VEs, high rpms and high horsepwer... 

CVTs are here to stay - from a fuel-efficiency and performance standpoint, they are the ideal transmissions. They'll make cars cheaper on gas and faster at the same time... sounds too good to be true. For us enthusiasts, it probably is.

I think engines are going to be built more and more like diesel engines because with a CVT, only a small portion of the rev range becomes important. an ideal engine for a CVT would be one with a large peak in torque somewhere in the low to mid RPM range. It will spend most of its time at this peak - a specific range of RPMs - while constantly adjusting for the optimum gear ratios. CVTs don't need high redlines, VTEC, VVL, or variable-anything for that matter because probably 90% of the engines rev range becomes a lot less significant. Maybe we'll all be driving CVT diesels in the future... though I hope not.

When conventional 5- or 6-speed transmissions go away, so will all of our hopes of the return of great engines like the VEs and RBs... High-revving, high hp engines won't matter anymore. In fact, I will go so far as to predict that when CVTs take over, torque ratings are going to become more important than horsepower ratings. Who needs peak horsepower ratings when it is actually lower than than the peak torque rating? 

Cars of the past will only keep killing our planet unfortunately, so car makers need to rethink the way cars are built. With fuel efficiency and emissions their priorities, we have to live with the new trends in engine and transmission design.


----------



## lshadoff (Nov 26, 2002)

sethwas said:


> I don't see what RPM has to do with torque in racing.
> It's like Ferrari v. BMW in racing. The Ferrari can power out of corners better, but the BMW can beat it in the straightaway. It's just a matter of design.
> 
> If the engine makes more power, then it can be geared higher and still accellerate as a weaker engine with more RPM and gears. The spin to 4500RPM can take just as long as the spin to 7500RPM.


To illustrate your point. In the early 1960s I watched a sports car race at Bridgehampton Raceway. On the track at the same time was a 428 Cobra and a Birdcage Maserati (3 liter, I think, http://www.users.waitrose.com/~enrico/maser12.htm). The Cobra had MUCH more acceleration and ended up passing the Maserati in the twisty portions of the course, but the Maserati passed the Cobra on every lap on the back long straightaway. It was reaching 180-210mph.

Both cars were awesome!

Lew


----------

