NZ951

Ok made some changes,

I will add list categories as they come to hand, but no point in doing it if there is only one or two, so spread the word. There will be an overall top 50 now too... no matter the model or displacement. I will add the model category as people advise it. Might be easier to sticky this too...

333pg333

I mean when you think about it, there are cars out there making buckloads more hp than our top cars here and they often have similar or smaller displacement. Or look at some of the hp figures coming out of the tuner 996/997 turbos. Sure they're 3.6+ltrs but what can we expect with some of our cars starting to creep up over 3.0ltrs? Of course this isn't really a dyno queen game as our prevailing impulses are to have a car that performs on the track, not just the dyno, but still. We're really 'lagging' behind here...

NZ951

Yup, you just need to look at the Toyota 2JZ GTE (3.0) and the Nissan RB30 (3.0) making over 1000whp pretty "easily". I have seen lots make 550WHP at 15psi.

My flatmates SR20DET (2.0) unmodified motor makes 420WHP on 22psi.

I know this isnt fair either but the Honda S2000 F20 (non turbo) motor (2.0) makes more power than our 2.5 turbo!

DFASTEST951

Isn't that because the blocks are cast iron and ours is aluminum?

blodstrupmoen

The 2,5 is a 30y old engine now , how do they compare technically to the modern V6 and straight sixes ?

In my daily driver there is also a very old engine with a iron block derrived from the M1 race car .. (it`s a 3,8 straight six w / 340hp) , with a little breather help it could easily break 600whp . The 3,6 block can take a lot of punishment and 1000hp + is (almost) common ..

Structual strenght and cooling ability is a key factor I think.. ?

Special tool is Push the envelope on the 2,5 .. And he has major issues to overcome 600whp @ race gas ..

NZ951

The Supra and 968 motors were introduced in the same year

blodstrupmoen

968 based on a 30y old engine cause Porsche had to cut cost at the time , and the Supra ?

Duke

A very important factor not mentioned here is the amount of cylinders.
In the end making hp's is all about displacement, rpm and VE. And it's easier to flow 600 hp divided on 6 cylinders than divided on 4 cylinders.
Compare the total port area and total intake/exhaust port CFM values.

It's also easier to get high rpm safely with the displacement and power spread out on more cylinders. That means lighter internals and lower piston speed (if the stroke is less.)

When taking this into account it's very easy to understand why the 3 liter 951's won't make power nowhere as easily as the 3 liter Supras.
You are really comparing 3 liters spread out on 4 cylinders that inhales through 4 valves and exhales through 4 valves with 3 liters spread out on 6 cylinders that inhales through 12 valves and exhales through 12 valves.

With that said, it's still a matter of willing to push the boundries.
Imagine the difference if a 3 liter 16v longblock were easily attainable for less than $1000... then you wouldn't have the thoughts of the money and time to source a new engine in the back of your head when setting the boost...

333pg333

Well these are fair points, but there are still Jap i4's making much better power than ours. So what if we have eg 3.4ltr with 16v and some other crucial changes? Sure 6 pistons are an advantage but is it a 50% extra advantage?

Duke

But to be fair, the high dyno numbers of the engine's you are speaking are done at very high boost with race fuel.
With runs made on the same fuel we can calculate how much power each engine produces for each liter of displacement and each psi of boost. Only then can we compare and judge how efficient each engine is.

With the 16v head we got flow enough to compete with the Jap I4, but we still need to rev it enough to get similar output. 8500 rpm is a bare minimum, many high power Jap engines runs 9-10 k rpm.
And since power is an output of torque and rpm....

So, build an 16v turbo engine that can spin to 9000 rpm and there will be "no problem" to get similar results as the Jap engines.

Note - I did not mention reliability here

toddk911

Exactly why I tried to start a "boost vs hp" thread a while back but no interest. But maybe if boost and octane used on this overall chart will solve that.

I don't care if someone made 600hp on 120octane and 40psi. I am more impressed to see someone make 400 hp on pump gas and 15 psi.

So, as you mention, if boost and octane are also noted with the dyno numbers we can break down hp per boost and thus reveal the most efficient motor on Rennlist.

This will also aid those that are doing modifications to see what parts/improvements yielded the best/most efficient results.

Corleone

Here is mine:

3 liter 8V

449 rwhp
455 nm at the wheels (336 lbf/ft)

This at 1 bar of boost (approx.15 psi)

Now more boost and E85.

AO

I'm not biggest 928, but at least I can represent.

Andrew Olson 441 RWHP / 395 RWTQ (SuperFlow)



FYI, I'm running about 9psi and have done some tuning that should put me in the 47X RWHP range, but then I just blew a head gasket last week. I'll be back in the spring.

SoloRacer

Funny thing is that all anyone seems to care about is peak HP numbers. I've seen 1000 HP Supra's and their dyno sheet looks like an EKG. They get 1000 HP for all of a few seconds. Makes for great bragging rights but not really that good for any kind of road course use. To my knowledge the Supra isn't a very popular car for road course racing here - it's just not that competitive. A much lower horsepower GT3 would spank it six ways from Sunday around Willow Springs or Watkins Glen. I think I also read that the factory pulled the stock 6 cylinder in favor of their turbocharged 4 for racing in Japan.

Is there a meaningful way to measure the powerband of an engine and that can be used to compare one to another? Peak dyno numbers really don't mean much in real world situations.

AO

I'm sorry but I cannot help but see the irony in this post considering your signature.