4g61t.org

i have a mirage and i have a 4g63t head sitting in the corner of the garage and was wondering if i could us it on my mirage?
I also have another 4g61t head to compare and other than the 4g63 head having bigger ports it looks the same to me!

So question is what will happen if i fit it, what is exactly going to happen?
is the compression going to be to low?
am i going to get no preformance from it?



mods i have are
16g turb
46g3 ecu
4g63 afm
4g63 fuel pump
4g63 injectors
4g63 intercooler
4g63 oil cooler
external w/gate

The 4g63 head has larger ports, but the combustion chamber is also larger, which would lower your compression and make the engine less responsive off-boost. If you are looking to boost performance with a head, you will need to look into the 1.8 4g67 heads, they have the same size ports as the 4g63 with the smaller cc size of the 4g61. Please fill in your location, you may have a 4g61t that came with the 1.8 head. To check, look for the numbers casted into the head by the thermostat housing, a "16" is a 1.6, and an "18" is a 1.8.

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John
89 Colt GT(2)
88 d50 4g63t, crower 272's, dsmlink

He mentioned the ports were smaller on his 61 head. But considering the ports are overkill on the 4g63's, you will only notice a loss in performance with your current mods. Just use the 4g63 cams in the 4g61 head and retard the exhaust cam one tooth.

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Turning a 4g61t into 1595 cc's of FURY!
10.995 @ 134.44 - http://www.youtube.com/watch?v=bZXvcvzuWGQ

SOLD to the fastest shifting hermaphrodite in CO

So, 2.0 turbo cams will fit directly into a 4G61T head?

Yes

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John
89 Colt GT(2)
88 d50 4g63t, crower 272's, dsmlink

Thanks.

The 4g63 head has larger ports, but the combustion chamber is also larger, which would lower your compression and make the engine less responsive off-boost.

ok good.
what i am looking at idealy using the vehicle for is mainly drags 1/4 mile,
no real street use.
so from what ive heard its not going to be a explosion if i install.
its just i have the 2.ol head and i dnt have to go hunting for this 4g67 head, kinda slack but im in a hurry to get the car modded more.

Simply run the it with a 61 head.

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John
89 Colt GT(2)
88 d50 4g63t, crower 272's, dsmlink

ok lovely.

thanks for all your time!

Stock 4G61T's with a larger Throttle body as the only mod directly at the intake mouth, have been taken into the 300+ HP range and without a plethura of expensive parts either. You're good to go with a 4G61T head and you would maintain a little more torque down low as well, due to not losing a bunch of compression ratio points.

thank you Flying Eagle
i am in the process of finding a 2.0l N/A throttle body.

tht is the one for best performance right?

There is no performance difference between the turbo and non-turbo throttle bodies. They are the same size. The non-turbo throttle body is better because it allows you to use a silicone coupler right off the inlet, instead of having to use a flange and bolt the pipe into the throttle body.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

I highly recommend not doing this...my colt had that done when I bought it from my friend and it idled like a piece of crap....and noticed zero difference in performance. I had similar mods:
14B
1G MAS
450's
1990 DSM ECU.

the car was so hard starting too, it almost killed the battery before it would start, then it would chug away.

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http://memimage.cardomain.net/member_im ... 3_full.jpg

with my throttle body i assumed it had twin butterfly and the N/A 2.0l model has a larger single butterfly, but with out a doubt i could be wrong.
where i live it is dirt cheap for the 2.0l throttle so i guess i cant go wrong.

thanks again guys for the knowledge!