Disappointing Dyno Result

[jonnaz]

Hello.

The car has been on the Dyno today for mapping. car is running VEMS so I have done the mapping however the result for power is down on where I expected it. The figure shown on the plot is Crank HP 483.6 and 440 lb/ft peak torque. I was expecting somewhere near this at the wheels. Or am I being over optimistic.

The car is running a HX35 turbo.
what I think is a china Large intercooler (Got with the car when I bought it)
044 fuel pump relayed
custom reverse intake manifold, this uses the standard 3b runners into the cylinders.
intake and exhaust piping is all 3 inch.
Tubular Exhaust Manifold, screamer pipe and Tial v44 Wastegate.
v8 coil conversion

I have attached the dyno plot and also my vems log for the run.

The car to me seems to be restricted from 6000rpm as the torque and power drop off. it was always going rich at the top end on different boost levels indicating poor pumping / breathing efficiency of the engine. I think the restriction is on the inlet side, I suspected the Intercooler but Im not so sure anymore. could it be the inlet manifold? or the Cylinder head itself? the head is standard.

Another ting I have noticed in the Log is; the spark angle recorded is about 7deg more that the value in the indicated cell of the ignition MAP. For info It is not Knocking.

All comments welcome

Project thread was here with more info on the spec.

http://www.s2forum.com/forum/showthread.php?t=59686

Thanks

Alex

[jonnaz]

Attachments

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[mike74]

I'm no expert in mapping so can't really comment too much BUT I have heard of too small plug gaps giving similar problems. What have you got them set to?

[Billman]

As you see it is going too rich above 6000 rpm

[AQTdriver]

I had 480 out of a standard engine with ported head and standard im and ic.. So you should be seeing around 550...
I don't think the turbo is capable of much more..

[prj]

480hp is not bad at all for a hx35.
Torque dropoff is expected, because the turbo exhaust side chokes the engine above that RPM.

If you want this at wheels you need a HX40 minimum.

Forget 550hp on a HX35. Fairytale world.

[Thuppu]

Good result for a standard HX35, but can be better with an HX35 super.

[prj]

I don't think it is going to be any better with HX35 Super.

HX35 Super gets usually between 510 and 530hp and that is with water/meth injection.
Without it's not more than 480hp as well..

[quattrostyle]

And it's called a ''Super'' because..?

[Thuppu]

Of course it depends of the dyno, but a friend of my have an S2 with an HX35S with a tiny #8 motorsport hot side, VEMS and 510hp without water/meth inj. And the restriction was the fuel pump(walbro) as it started to go lean in the upper end. He has a 60mm WG though.

[Jamo]

I think that is a good result on a HX35 I wouldn't have expected anymore than 500 max with all bells and whistle on that turbo

Impressive that the curves are flat, a tuner could probably squeeze a bit more out of it

What were the AFR's and egts?

[jonnaz]

Ok thanks.

PRJ i trust your judgement as i know you have mapped many of these cars.

Maybe i was being a bit over optomistic with my estimations. 480hp at the crank equates to about 360 ish WHP. Seems like that is what is expected of this setup. The yorque curve is nice and flat.

I was pulling fuel from the top end to try and lean it out the engine is just choking above 6k.

Jamo MAX EGT was 683 deg. Afr labda 0.74 at the top end between 6.5 and 7k. The target lambda is 0.79. Maybe i should try leaning it out more above 6k. Im not running closed loop lambda contol above 3.5k.

Billman did you notice the spark angle in the log doesnt match the cell value in the ignition table? I find this strange.

Thanks.

[Thuppu]

If it doesn't knock at all, maybe you get 500 with a little leaner upper end and a bit more timing. Have the engine timing been checked with a strobo?

[EspenW]

That is a sweet as pie torque curve.
Don't fret about peak hp numbers, your car is likely faster on the road than similar cars with more peak hp, but a more peaky torque delivery.

Also, Dyno Dynamics numbers are real world, and not dreamworld like many others.

EDIT: I mistook the boost curve for the torque curve.... still nice, though, but that boost curve is sweet. I want boost to stay up like that too However, I get that same boost 500rpm earlier, so it is a tradeoff.

[jonnaz]

Tuppu yes i have check the engine timing with a strobe using the ignition lock function in vems.

i will try to lean it out a little to get it back on target. see what happens.

Espen thanks. what turbo are you running?