JAS's Rebuild and twincam conversion. 302kw atw baby!!!

Display your ride and post power figures, dyno runs, drag and circuit times.
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JAS
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Post by JAS »

dirtygalant wrote:yeah that boost build up curve is not the best.. it almost looks like it's building up and as soon as it builds decent boost the wastegate keeps it steady at 21psi, I would try raising that up to 25psi and see how much power you get - my thoughts are that the turbo is perhaps a bit too big for your relatively low boost and mid-range power orientated application.

Other things I would be looking at is perhaps ignition timing, camshaft timing and that the camshaft duration is ideal for your application. Out of curiousity, have you done a compression test on the engine recently? if so what are the numbers?
Yes the boost comes on quiet slow. The tuner did say the motor feels a little lazy, ie low compression. I remember the engine builder saying it was around 8.4 which I was happy with at the time.

The boost is steady once is gets to full boost but the tuner did say that the motor behaves like its got a restricter in the system like the rally cars use. The power builds up then drops off before red line.

I did mention to the tuner about 25 psi which he would be happy to wind into the motor. But the fact it looses power before red line does worry me a little and Id like to get that sorted before I wind more psi into it.

The tuner did check the ignition timing and camshaft timing. Ive got standard VR4 cams but the tuner didnt seem to think that they would be slowing things down much.

Ill also be checking for a pressure drop on either side of the intercooler.
1984 Sigma Super, Turbo Wagon
1990 GSR-VR 50,000ks
1984 GSR II 4G63 302kw atw at 24psi

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87_starion
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Post by 87_starion »

Odd that the power is dropping off considering how late it makes boost.

Paul Ohlsen told me about 10 years ago VR-4 cams were only good for 350Hp, after that things don't breathe well. Thats was a long time ago though.
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fugazi
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Post by fugazi »

Sounds like they are a bit low on lift...
Anybody got specs on VR4-cams?
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OLD FART
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Post by OLD FART »

fugazi wrote:Sounds like they are a bit low on lift...
Anybody got specs on VR4-cams?
or duration
I've had mine since 03 07 92
85 JB 2323cc DOHC 4G63
THE OLDER I GET THE FASTER I WAS
GROWING OLD IS MANDATORY GROWING UP IS OPTIONAL
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JAS
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Post by JAS »

Hmmm

I did ask the tuner if the cams could be holding things up but he said they have seen 400hp out of early evos with standard motors. Just bolt ons. Same size turbos as Im running etc.

Ill have to find some boost gauges and see if there is a pressure drop between the turbo outlet and the inlet mainfold. Maybe the cooler is restricting things????
1984 Sigma Super, Turbo Wagon
1990 GSR-VR 50,000ks
1984 GSR II 4G63 302kw atw at 24psi

http://www.facebook.com/marvinmartiannz

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EVOMINUS
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Post by EVOMINUS »

The vr4's cams are very very mild trust me!!i think they are something like 251 with 9.1 lift or something near that!If you change your cams with something more aggressive you will see very big gains!If you can't afford cams right now ,change your pulleys with adjuastable once to see a little higher rev power...
fugazi
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Post by fugazi »

251???
The Galant GTi (Euro-spec) is 258° i think...

Get some with 262°s... or more. It will make a happier motor allover!
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EVOMINUS
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Post by EVOMINUS »

told you something like that!!!!although when i rigrinded mine when i first measured them i think i remenber that they were close to 251!And mine was jdm surely
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JAS
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Post by JAS »

So even a upgrade to EVO 1, 2 or 3 cams would help then??

Has anyone got specs on these??
1984 Sigma Super, Turbo Wagon
1990 GSR-VR 50,000ks
1984 GSR II 4G63 302kw atw at 24psi

http://www.facebook.com/marvinmartiannz

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Lunacy
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Post by Lunacy »

Jase dont bother with e1-3 cams they arent an upgrade at all over the vr4 ones. There was a post on nzmmc forum awhile back on specs of all factory mitsi cams and it ended up being a myth that the evo cams are an upgrade for vr4 ones. Def check the boost drop out 1st but as others said may be time to talk to kelfords for a set of tx272s as that will make ur car very happy :-)
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JAS
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Post by JAS »

And very lumpy lol

Thanks mate.

At most I think Id go 264 inlet and 272 ex

Can't really justify spending more money on cams, gears and springs at the moment. Maybe in a few months, or when I sell my legnum.

Ive bought myself a pair of cheap boost gauges so Ill hook them up this weekend and see if there is a pressure drop in the system.
1984 Sigma Super, Turbo Wagon
1990 GSR-VR 50,000ks
1984 GSR II 4G63 302kw atw at 24psi

http://www.facebook.com/marvinmartiannz

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JAS
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Post by JAS »

Are the valve springs the same between the EVO 1,2 and 3 and VR4?

Found these http://www.trademe.co.nz/Trade-Me-Motor ... 457624.htm
1984 Sigma Super, Turbo Wagon
1990 GSR-VR 50,000ks
1984 GSR II 4G63 302kw atw at 24psi

http://www.facebook.com/marvinmartiannz

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dirtygalant
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Post by dirtygalant »

valve springs are the same, and I even think the exhaust valve springs are the same right up to evo 9.

VR-4 cams are the same spec as Evo2/3, Evo1 cams have the same duration but less lift. They all have different part numbers, but the Evo2/3 cams superceded the VR-4 cams in CAPS/ASA.
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thrash
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Post by thrash »

so same cams but different piort design between the vr4 and the evo 2/3s?
quest wrote:
WANTSOM wrote:Personally, I find sloppy boxes very unsatisfying. I like them tight and taught to the point that if you dont have to push to get it in then its probably too old and time to get a new one :P
don't try explaining that to her tho..... just leave. lol
dirtygalant
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Post by dirtygalant »

yes.
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E39A Galant VR-4 Evolution | A164A Eterna GSR | 6G72 RWD Conversion Forum
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