faust

A mate bought a set of alloy heads got them flowed at 504hp put in a crane cam 2040, 1.61 yella tarra rockers and new non adjustable pushrods for his EL XR8, manual.

Car already had exhaust, fuel system, air flow meter and engine management system done. Compression ratio was 9.3:1, r58cc. Made 170.4rwkw.

Once the heads and cam were installed it made 173.6rwkw.
What happened? We were expecting at least 200rwkw.

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'90 Mitsubishi GTO
3.0L Twin Turbo V6
140AWKW

BossHoggett

I d be looking at engine vacumme first.

Surely your dyno operator saw stuff in his readings that would alert you to the problem?

russxr67

What make of alloy's?
Pro comps,AFR,?????????

faust

Heads are pro comp. dyno operator wasnt much help at all.

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'90 Mitsubishi GTO
3.0L Twin Turbo V6
140AWKW

disco_336

ECU ECU ECU!!!!
u can force more air in, but u cant force fuel in unless you tell it too....
its called a tune

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If ya want more inches "Stroke" it

faust

It's been dyno tuned... Twice actually.

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'90 Mitsubishi GTO
3.0L Twin Turbo V6
140AWKW

MCEcomp

I ve seen the same thing before...

If there is no restriction on the intake or exhaust, its in the ECU.

You need to piss the factory computor and go aftermarket.

And no the piggy back systems dont work either

disco_336

it hasnt bin re-mapped
you need another ECU, you cant change factory settings on an ecu that has already bin programmed unless u flash tune it

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If ya want more inches "Stroke" it

skidmarx

yep, its in the tune

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100% pimp factor, long live the VK

CK_318

as the others have said it definitely needs to be re-tuned again

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faust

Alright then, so what's the point of a piggy back computer if it cant be retuned? And we're talking a whole new ECU?

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'90 Mitsubishi GTO
3.0L Twin Turbo V6
140AWKW

skidmarx

its like a black and white tv, the old farts used to put coloured selephane over the screen to make it look like it was coloured, but we all know it just looked stupid and not right


a piggy back ecu is very expensive selephane

__________________
100% pimp factor, long live the VK

faust

This is what the tuning program for the ECU looks like. What's missing with it that would make it behave in the current manner?

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'90 Mitsubishi GTO
3.0L Twin Turbo V6
140AWKW

wabbit

were the before and after KW readings on the same dyno?

does it drive any different?

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Nothing to see, here


Move along, please

.

allports

What cc is the intake port?
I did one on an EB for a mate of mine with 165cc afr cnc, flowed 1st 475hp@.600 did the bowls and short turn flowed 525hp, 224 @50 hyd roller std inlet and throttle body with a good exhaust. Made 202rwkw ran 12.9 @105mph with a T5box & 3.27 gears. He then put a 4.10 diff in and it ran 13.1@ 104. We pulled the heads because the air was going sonic in the port. I re did the whole port enlarging it to return the air speed back to where it was via the rpm at the 105mph. Didnt flow them not enough time. At the dyno the car then made 221rwkw and ran 12.68 @ 109MPH. Still with std injectors and std manifold/throttle body.
I dont really think your ecu is the issue.
Maybe you need to know what your fuel pump is like meaning the condition.
It could just be the tune, it could be the igniton or it could be the velocity through the heads, if you have a larger head on there the charge will be slower than it should be and therefore reducing the intake charge.
Also bear in mind the alloy head with 9.68 comp ratio is like having 8.68 comp due to the dissapation of alloy over the cast iron head. In most cases you can go up 1 full point in compression when changing from Iron heads to alloy heads.

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