391HP from 2988cc L28 stroker

[Riceburner]

Is 391hp achievable from a stroked L28?

 

http://forums.hybridz.org/gallery/album/1377-fgt-240z/

[Gordo]

Only in America.

[NZeder]

And 8200rpm with a full size flywheel - why would you bother with such a large lump of metal at the rear of the engine.

[KatoKid]

15.2:1 CR........will require rocket fuel

[C.A.R.]

Rebello Racing 3.0 liter engine. L28 stroker with E-31 head, 2988cc's with 15.22:1 compression ratio, Honda rods, .620" lift, Extrudabody 48mm ITB, taper bore fuel injection, Stahl 1.75", 6 -2 header and Adaptronic engine management.

Dyno tuned it makes 379hp@8200 rpm with stock oil pan. Have since install an Arizona Z Car 6 quart pan with windage tray and a Teflon Ishihara-Johnson Crank Scraper, for another 12 - 12 hp.

 

 

AAAAAAAAAAAAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!

Rebello Racing

^There's it's first problem!

 

And not with that build specification. And it's american HP, so in real would figures it might make 260hp - if it's lucky.

[gav240z]

The Japanese seem to have managed it if you believe this.

 

 

American dyno's seem to be overly generous in terms of the way they measure HP.

[peter mc]

hahahhahahahhahah funny stuff got to love the bs they come up with

[d3c0y]

Oh come on guys, it's only 130hp/L whats hard about that with a 2 valve non cross flow head?

 

 

How about 12hp from windage tray and a crank scraper!?

[Riceburner]

Oh come on guys, it's only 130hp/L whats hard about that with a 2 valve non cross flow head?

 

 

How about 12hp from windage tray and a crank scraper!?

 

I have one of those crank scrapers on my engine 

 

Why do they get such 'different' HP readings compared to ours?

[Agno]

A dyno is just a tuning tool and nothing more. You can make more "power" just by changing the input parameters in between runs. Because of the massive amount of variability in how people set up their dynos some are "happier" than others.

[dat2kman]

Traditional water type dyno never lies.

But these are too cumbersome and a pita to use.

 

The decent ones were the old Heenan & Froude, like the one at 25 Wren Rd Moorabin, next to Mondell's shop.

That thing has had more owners than we've all had hot dinners.

[MyEnquiringMind]

a very indirect science, rear wheel horsepower is calculated as torque produced X road speed, the assumed losses through the drivetrain are incorporated into a "fudge factor" when programming, if you turn the theoretical losses up then the horsepower (at the flywheel) figures go up... lets not open the can of worms that is peak versus usable horsepower... **stands back with can opener in hand...

[Riceburner]

So basically this 'fudge factor' is operator controlled, meaning they can put in whatever they want and then this alters the final power/torque figures?

 

While being a great tuning tool for AFR's and fuel consumption, those final power numbers are useless? Are the correction numbers/figures shown on the print out graphs?

[Six_Shooter]

A few years I was helping a friend of mine with his drag car, Big Block Chevy, 13 or 14:1 SCR, Big Chief heads, a cam that produced about an inch of lift, etc, etc. We went to the engine builders, where they had a chassis dyno and a purpose built device they called the "Dyno Rider" made just to dyno run engines. It was a two wheeled device, with a known trans, and a known rear end, etc, so they could accurately determine what the engine itself was making.

 

It was re-freshened and a slight upgrade rebuild from how he received this engine, he wanted to change classes and he needed more power N/A than he made previously with spray. And we had a couple intakes to test, as it turned out we only had one, because he was supplied with the wrong dual carb tall intake. :facepalm:

 

To get to the meat of this story we made a run, where the engine made 980HP and around 1050 ft/lbs torque. As we were talking with the dyno operator, we started discussing "correction factors". This was eye opening. Without making any other runs, just by applying different correct factors to the same run, that engine "produced" everything from about 250 HP all the way up to about 1400 HP.

 

It's because of stuff like this that I don't care what a dyno says for numbers, because they can be made to lie rather easily, both for more than what the engine actually has and less. A dyno can be good for making changes and comparing on the SAME day, and seeing what does improve and what doesn't.

 

Around here, we don't race dynos, they are difficult to stage.

[PZG302]

^^^+1 I've had a couple of dyno operators ask me what power would I like out of my engine when tuning or checking something.

 

The best dyno is of course the old stopwatch

[dat2kman]

Lap time compared to other cars lap times, with tracks in close to similar conditions, is a pretty good indicator.

There are certainly some dyno queens out there, on the rolling road/chassis dynos.

 

When putting engines on an engine dyno, the most important thing to be asking is, when does it produce peak torque, and where does it drop ff.

HP is a by product, and of secondary relevance.

 

You should then look to diff ratio the car for the highest attainable speed you want to achieve, then select gear ratios that on each gear up-change, the engine rpm drops to that peak torque output figure, and then upchange at where torque falls off, or peak HP is attained, then the next up-change, rpm should be back down at that torque figure.

 

Eg, i have a four cylinder car, at 5500 is peak torque, at 7500 is peak HP, as long as i keep engine between these two numbers, via diff and gearbox, relative to a given piece of road ( my caee, a racetrack) i know the car will work.

 

Try explain that to a dyno queen owner! All they care about is " whats max HP dude?"

 

[d3c0y]

Problem then is you have driver correction factor to deal with. At our "grass roots" level, how do you account for sucky drivers?

[PZG302]

You use the dyno as the tuning tool it is and not worry about the numbers just the shape under the curve.

 

I used to race with a car that was by most guesses at least 100hp down on other cars in the mid 90's, was still as quick on tighter circuits like Amaroo and Oran Park South circuit, and not that far behind on "power" circuits like Eastern Creek and Oran Park GP. The car was still good enough with me pedalling it to win a state championship so you don't need big numbers on a dyno to get results.

 

For any track work, where you want to go really fast, as I have said before and yet to be proven wrong:

You want to go seconds faster spend your money on brakes and suspension

You want to go tenths faster spend your money on the motor.

 

A well set up easy to drive car with moderate power levels will generally be quicker than some evil handling pig of a car with a mega horsepower motor.

 

A well set up and easy to drive car with a mega horsepower motor is not as easy to achieve as you would think, especially for gentleman racers and sprinters like ourselves.

[260DET]

Problem is with the yanks who actually believe their big numbers even though they make no sense. VG30ET was a good example of nonsense power claims, apparently because some of the race engines back in the day did do big numbers. With huge boost, NISMO heads which are completely different to stock and so on.

 

I've had a few goes at them but they believe what suits them to believe, their old clunkers develop more power than a modern GTR or P car turbo.

[d3c0y]

I remember those electromotive VG30ETs quoting at making like 850hp made me feel very sorry about my VG30DETT.

[260DET]

Yes they did but were a completely different engine to a stock VG30ET which has a very restrictive head design which can't be improved much by conventional means. NISMO heads are a completely different and way more effective design requiring custom inlet and exhaust manifolds, at one time I would have bought a pair if they were available.