944J

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333pg333

Why? How much HP are you chasing and what's your budget? What do you want to do with the car? Sid has proven that you can get some decent power out of some of the stock components but this is for 1/4 mile stuff. The 1000whp title is a waste of 'ink'. The only way you're going to get near that sort of power is with an open cheque book...and virtually no stock parts.

944J

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Paulyy

Sid is Blown 44.
Shawn is Refresh951.

Id also be worried about how you're going to keep the head on.
the size of the turbo you'll need wouldn't even spool under 5000rpm
the gearbox wont even hold up that much power.

Remember these are 4 cylinder engines, and not LS1's where it's no problem getting to 1000rwhp.
1000rwhp on a ls1 is like ~430 rwhp on a 951.

944J

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Rogue_Ant

With all the threads you've dug up lately - one has to wonder what is your real point..? Can you make more peak hp with XYZ car/engine than the 944 - sure. The 944 was never a peak-hp car.

Bob Norwood did not make 900hp on pump gasoline with a 944-based engine. Sorry, it simply isn't going to happen.
Race fuel, or alcohol it is probably possible.

The biggest peak-hp advantage a lot of imports have is the ability to rev (and head-flow compared to our 8-valve heads). That Honda you linked made its peak hp at 9700RPM (!). Horsepower being a measure of work, with the Honda engine spinning nearly 50% faster than what we spin our 944 engine, then I would definitely expect it to be able to do more work (horsepower).

Additionally, nobody making obscene power numbers w/ small displacement is running stock parts. Even the 2JZ (Supra) guys build their motors when going over 700rwhp or so. Which is why your question of what the stock parts are capable of doesn't make much sense...

Adonay

Most if not all high boost 944 engines have problems with headgaskets.
And thats when we are talking about 25-30Psi.
50Psi not doable in my opinion.

What could have been done that has not been tried ? bigger studs and deckplate+mls gasket= Done already.

V2Rocket

A Cummins 5.9 diesel has ~102mm pistons...

Mill yourself a billet block and crank to blown944/refresh951 spec, put a worked 16v head on it, clamp it down with big studs (maybe add some more), trick exhaust, and a turbo off a locomotive...

reno808

seriously

Crackership

I wish I had this picture to you guys... My dad's got it, maybe I'll remember to get it from him some day... Anyway, he used to race what he calls "Pumpkin-Seed" boats when he lived in Florida.. If you do a google image search, you'll get an idea. Anyway, he and his buddies would build 12-15:1 engines for these things (race gas) and big open carburetors - which resulted in a lot of unintentional "water injection". So, to keep the heads on the engines, he and his buddies built basically gigantic U-bolts which they would strap completely around the engine and head to try and keep the head from lifting. He said they would let loose every once in a while, but they usually held together....

Not that that's really an applicable solution for the 951, but the thread just reminded me of it.

74goldtarga

All that matters (to people who drive cars and not just keyboards) is what you can build that will hold together at a racetrack, quarter mile, or daily driver over a period of years. Is it really important to know what you can do with a dyno only engine? The valuable question is what has been done (or could be done) that would hold up - engine cooling, transmission viability, reliability with sustained g-forces. 900hp might be possible, but who cares, it isn't going to hold up for more than a few glorified youtube recordings with a smart phone and then you'll never hear about it again. The engine that blows me away is the engine that Michael Mount built for Henk - lower the CR on that engine and optimize it for turbocharging and see where that goes, my (unenducated relative to others here) guess for real world HP is somewhere in the 600hp range - not really stock parts anymore though.

944J

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Rogue_Ant

For theory - fine.
If you want the 'academic' answer, then first lesson is to accept that some motors have inherent advantages/disadvantages compared to others...

Our engines have a huge bore, and there for big heavy pistons compared to the vast majority of imports. About the only one with a comparable bore-size, is the WRX, and they are typically staying under 7000rpm too. The large bore also means that the headstuds are farther apart. This makes it harder to prevent the cylinder head from lifting/flexing under high cylinder pressure.

The 944 cylinder head is not going to get you there - not realistically (for what that is worth in this thread). Using a 968 head would be the best starting choice, as it is DOHC, 16-valve, and the highest flowing stock head. I doubt there is any stock production head with greater flow (maybe the F20c).

Our engine is open-deck, with a habit of cylinder-walking. Yes, you can close the deck with a deckplate, but that still doesn't solve the head lift/flex issue. Additionally, our cylinders are just aluminum, so again this must be addressed by some sort of sleeving. However, with enough power the entire block starts to flex/twist... So now you need to mill a completely new block made from better material & designed with high-hp in mind. I HIGHLY doubt anyone could get this done for $5000. This isn't a Honda where the R&D can be easily absorbed into the manufacturing. No, even if someone did do all the work to actually mill a new 944 block, there would only be a handful of people willing to purchase it - because in very small volumes, the milled block would be extraordinarily expensive.

Yet another roadbump is the oiling system. Even at factory RPMs the oil-pump is cavitating. Raising the rev-limit only exacerbates oiling issues. So a dry-sump is a must-have for a high revving car (even that Honda had a dry-sump).

Regarding peak-hp, I don't think I've ever seen a 951 make peak hp at red-line, ever. Here is Duke's 3.0L with 968 head (the best flowing head available for our cars) 500+rwhp:

Duke Dyno

You can see it tapering off after ~6250rpm.
Here is Sid's at 520rwhp:

Sid Dyno

And his is plateauing after ~5500rpm.

With a big cam, and HUGE turbo, the power would continue to rise with RPMs... But high RPMs requires more yet. Valve-train must be addressed, which means solid lifters, exotic valve material, EMS that can keep up, ect. In-addition, I'm not even sure if our transmissions would shift at ~9000rpm. Even in the DSM world, which easily revs to 8000rpm, getting transmissions to shift at really high RPMs requires a bit of work. Furthermore, we don't have the toughest transmissions, and are quite limited for upgrades. Again that Honda was getting ready to install straight-cut dog-engagement gears - yet one more thing we don't even have the option of.

No, these cars engines are not similar to Honda-4s, Mitsubishi-4s, ect. If you must compare them to another engine, then compare them to engines with similar bore & stroke such as a WRX Sti, or Chevy ~327.

Regarding the "tons of examples of everyday joes making 1000+hp honda's and toyota's", well proportionally there are tons more Hondas & Toyotas produced. There are easily 100x more civics produced than 944s. Then start including Integras/RSX/S2000/Prelude/Accord/ect, that number is quite a bit more yet. Furthermore, go to the road-track and see how many of these high-hp imports are there. The 944s strength is on the road-course, which is what most built 944s are directed to .

Finally, addressing Bob Norwood. He is an undoubtedly knowledgeable man. But he is not the end-all expert on the 944. In-fact, there are plenty of people on this board who would walk circles around Norwood, regarding the 944. Whats more is that I've never seen any dyno or other quantitative data backing up Norwood's claims regarding this "900hp engine". Furthermore, there is the ambiguous "road race trim". Exactly what does that mean? For a high-hp dedicated build, I would be using either a quality race-fuel, or alcohol. I see no claim that he made any power on pump-gasoline. Ask you self this: 900hp out of a 3L engine is 300hp / liter. Can you find any car that makes 300hp / liter on pump-gasoline? The only chance would be one that revs to 10,000rpm. Pump gasoline will only withstand so much cylinder pressure, period.


All that said, I'm sure someone with a lot of $ could build a very high-hp 951. But the better question is why? If it is just to see if it could be done, then that is kinda moot... With enough money you can make nearly anything produce big numbers - so "proving" that it can be done again, on a different motor is redundant. Nope, people would rather have a realistic power goal, have fun with these cars, and enjoy them for what they are.

Paulyy

Thankyou. couldn't have said it better myself

Scott H

Step 1) Contact Chris White and get put on the waiting list for a billet block.

Step 2) Wait for Chris White to finish designing said block.

Perhaps those should be the other way around.