[Sebring NL]

Loose the K&N filter

Get the clearances and tb synchro doublechecked , replace ignition parts and crank/cam sensor

Still , dyno figures mean d1ck to me as they are not standardised.


Oh and I just read your sig, don't bother doing anything. Raising rev limit to 8000 will mean you probably won't be able to use up the current gas in the tank ouich:

 

[raymondw]

Raising rev limit to 8000 will mean you probably won't be able to use up the current gas in the tank ouich:

And I doubt that the harmonic balancer has been changed either, meaning that once above 7500RPM, the inevitable vibrations knock and weaken his engine into 'self destruct-mode'.

With other words; a stock S38 engine for road-use isn't safe to use above 7500RPM. The racing M88 (predecessor of the S38) engines that may rev up to 9k RPM are significantly different as all moving parts have been altered to withstand those high rev's, the improved flow of the cyl head and adaptations to the fuel injection system, hence it doesn't surprise me that the power of his engine continues to drop above 6900RPM, despite the raised rev limiter.

 

[DREAM 5]

I know that the 8K rev limiter isnt good and only ever use up to 7K. On the dyno after made highest power output we backed off, not point going to rev limter when not making more power. AFter installing the chip I felt the power gain so it has benefitted.

I think I will tune and get her back on the dyno for another run, what is good for intake and air filter?

And what is stockish hp at trteads anyone?

 

[farrell]

My stock 3.8 is was making near 280 @ rwhp when using a rolling road
Thats a hard comparison due to atmospherics & intake air temp
which will be totally different to your environment.
( that figure was a while back now)

I used the rolling road to diagnose fuel & spark issue.
The harsh environment tends to stimulate the failure modes.

Are you still running std maf.
That & intake temp sensor dont like superheated intake temps.
If you are running with out an air box or have have brittle / broken vacuum
hoses, there will be power reduction.

If not using extended rpm limit, why have it ?
I can relate 3 S38 engines in UK that had eprom with 7,800 rpm.
The owners all said...nah, dont use the max rpm..
Errr, whats that big metal thing thats looks like a con rod sticking out
of the side of the block then ?

Lets be careful out there.
Farrell

 

[stevie sam]

I love the CONROD bit Faz...beautifully put m8......this tuning thing really confuses me !!!!!!!!!!!!!!!!!!!

 

[A.W.O.L]

hmmm those are low numbers. Your 1/4miles isnt bad though, strange.

have you done a compression test? leakdown?

keep working on it and get that baby running solid

edit: what kind of dyno or "rolling road"?

 

[Cyrus]

I wouldn't get too upset about your dyno figures to be honest.

There are so many variables on a rolling road of which the biggest one is the operator!

Too many times we see dyno operators not allowing intake temps to stabalise and you end up running a car with intake temps of 50+ degrees....that isn't going to help the engine make much power now!

Tyre pressures are seldom checked and strapping techniques are poor to say the least.

Do you have details of intake and ambient temperatures, tyre pressures?

On the dyno graph where does it show the engine revving to? This is again is something that alot of operators get wrong.....simple rpm vs speed calibration!

Let us see your results on paper and maybe we can go from there.

Make sure to have your fuelling curve.

 

[jrobbo]

Ignore the absolute figures that the dyno gave you, they are not calibrated to any official standard and so can't be relied upon. FWIW though, I have had mine, and a couple of other E34 M5's on 3 seperate dyno's here in Melbourne, and they have all been in the same ballpark as your figures. For some reason, the UK dyno's always seem to read much higher, but again, without any official calibration standard, it's difficult to compare. Your 1/4 mile time seems right on the money, so I suspect that your car is producing it's full allotment of power.

Enjoy your car!

John

 

[Sebring NL]

+1

Like said before

Untill dynomometers are standardises and scrutineered across the globe*, comparing Aussi dyno numbers to any others is completely useless.



* note that I don't say: "Last week, an E30 M3 and a Thriumph Spitfire made stock hp figures on his dyno and the guy is Hesus Motorsport himself working on Schumachers car etc"

 

[DREAM 5]

I have got the readout of the three power runs, will post up sooon, later today.
I was chuffed I took out powerfulest 6 .
My tyre pressures were prob a bit low at 36 on rears. Prob should have had them alot higher.
I am going to put the car back down the strip within the next month and see if the chip has made any difference and only use 7K limit(lol).
What chip do other people use that are safe and use standard (sfae) rpm?

Thanks guys for the help

 

[DREAM 5]

I have got the readout of the three power runs, will post up sooon, later today.
I was chuffed I took out powerfulest 6 .
My tyre pressures were prob a bit low at 36 on rears. Prob should have had them alot higher.
I am going to put the car back down the strip within the next month and see if the chip has made any difference and only use 7K limit(lol).
What chip do other people use that are safe and use standard (sfae) rpm?

Thanks guys for the help

 

[jrobbo]

The Mark D'Sylva EAT Chips probably have the best reputation, and keep the stock rev limit. I have one in my car, and did back-to-back before and after dyno runs when I put it in. I gained an extra 11kW Max Power, and a maximum increase of 15kW.

Here is the link --> http://www.dsylva-tech.ca/

 

[farrell]

Agreed John.:applause:
Also :
Problems with resonance adversely affecting the crankshaft are 7,500
rpm up.
Raymond's concerns are exactly as my own.

I would suggest that an extended rpm limit should be no more than 7,400 rpm
Std power in a 3.6 is all done below 7k rpm.
I believe an well maintained engine with good cooling, no brittle vacuum hoses,
ignition system, etc will perform remarkably well.
Has the cars valve train been shimmed lately ?

Mark D'sylva was advising me on a difficult DME last week which needed
some work & removal of an aftermarket eprom.
Our discussion moved onto what customers expected from his eproms.
With a large old engine like the S38, alot of variables creep in.
results can be markedly different between vehicles.
Why ?
The engines are not mechanically self adjusting.
The MAFs do wear out beyond the ideal in 100,000 miles but continue
to provide service @ reduced efficiency for many more miles.

A good eprom will be mapped to provide ideal performance from a well set up
& maintained engine.
The trouble is, the technology to read, copy & generally f*uck about with
the cal maps is there for very little cash relatively speaking.

Over the years, one thing has become clear.
"A little knowledge is a dangerous thing"

I wish you luck with your investigations & hope the vehicle remains together
for you:thumbsup:

Farrell

 

[DREAM 5]

I have hardly ever used above 7000K, the car has driven a total of 113000K's.

I have noticed a differnece but wished I dynoed the car before chipping, I have a standard chipped computer at work which I may try and see the difference.

we have used 8K limiters on two e34 m5 B36's in the past which were used for classic challenges and tarmac rally's. These cars were driven hard weekend after weekend, and in a total of two years of having them we never broke anything major to call it quits.

S38 on the other hand was all problems when we took them into the high revs

 

[nebpor]

You've just reminded me I need to prod Mark for the standard chip I asked him for, I really want rid of the Superchips EPROM in my own car ...

 

[A.W.O.L]

pics of graph?