# GA14 ITB's



## FiredragonCT (Sep 1, 2004)

Hi Guys and Gals - been posting on and off on this forum - thought I might just share some info...

I was looking for a set of ITB's that will fir the GA14 motor my car is equipped with - after looking at all the technical specs (Q&A section on Jenvey site) it became apparent that I needed a set of 35mm ITB's - and we all know nobody makes these...

Finally sourced a set of 35mm ITB's off a Kawazaki GPZ 1100 - the spacing is almost perfect and the TPS (throttle position sensor) is almost an identical fit!

Used the intake off a GA16 and cut it off - now the fuel rail is fitted, injectors and Fuel pressure regulator are in place and the ITB.s have been cleaned and ported - all thats left for me is to have the runners and trumpets made up and fitted as well as the vacuum line modification!

If anyone is interested I will post some pics - this conversion should work perfectly on the GA16 as well - but I do recommend that this very late on your list of mods and that you have an aftermarket chip or CPU to cope with the tuning...

I am expecting approximately 25% gain in mid-range torque from this mod - but will keep you updated.

Mods so far - 272 degree billet forged cams - exhaust headers and full stainless steel freeflow system - Dastek unichip and rev limiter override - custom intake manifold (single throttle body) - performance filters - modified fuel pressure regulator. Also a full racing suspension and tons of exterior mods...

After this I will be lifting the compression ratio to about 10.5:1, knife-edge the crank, shotpien the conrods and balance the whole lot - she should be able to rev to 9000 RPM then....

Hope this info helps someone as info on the GA14 is VERY hard to come by!

Cheers


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## wes (Apr 30, 2002)

FiredragonCT said:


> Hi Guys and Gals - been posting on and off on this forum - thought I might just share some info...
> 
> I was looking for a set of ITB's that will fir the GA14 motor my car is equipped with - after looking at all the technical specs (Q&A section on Jenvey site) it became apparent that I needed a set of 35mm ITB's - and we all know nobody makes these...
> 
> ...



What are you doing to the valvetrain to rev that high? The stock asembly will not liek that one bit and float will def. be an issue! Secondly do you think the car is going to make good power up that high? 

Otherwise the ITB stup sounds cool. Oh and you mention ITB's and then a single TB, which are you going to do?


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## himbo (Sep 20, 2003)

i wonder if theres a way to make itb's work on a turbo just like the GTIR manifold? that sounds like a killer new project wes :thumbup:


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## FiredragonCT (Sep 1, 2004)

Well I dunno how our motors differ from the ones you guys get there. My guy here told me (was a Nissan mechanic for 7 years and now works at a performance shop) that the valvetrain can handle that easily. She currently has no problem up to 7500 RPM - and still making power there.

I will however go to wilder cams like 300's or 308's and this will make street driving a pain. 

How hard will it be do do a Turbo or Supercharger through the ITB's?


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## FiredragonCT (Sep 1, 2004)

wes said:


> What are you doing to the valvetrain to rev that high? The stock asembly will not liek that one bit and float will def. be an issue! Secondly do you think the car is going to make good power up that high?
> 
> Otherwise the ITB stup sounds cool. Oh and you mention ITB's and then a single TB, which are you going to do?


I currently run Single throttle body - now converting to ITB's


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## wes (Apr 30, 2002)

If you want to go forced induction you will have to make a plenum. And how do they know it's safe? Have the doen valve train harmonics testing to see where float occours? And how do you kno it is making power up there, do you have a dyno chart that shows a steady increase in power at 7500 rpm's?


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## FiredragonCT (Sep 1, 2004)

wes said:


> If you want to go forced induction you will have to make a plenum. And how do they know it's safe? Have the doen valve train harmonics testing to see where float occours? And how do you kno it is making power up there, do you have a dyno chart that shows a steady increase in power at 7500 rpm's?


Currently my dyno chart shows the power curve starting to lose the harsh climb at around 7500RPM - but still climbing - from what we can determine on the sheet it looks like gains will continue untill 8500 RPM - we will be revving her to 9000 to make sure I get into the high powerband when shifting. Remember that this car is mainly for track use.

They have done various harmonics tests on the motor - as he was involved with Nissan Motorsport South Africa - the tests have also been confirmed by Van der Linde Motorsport Developments.

They even modified a SR20 motor to rev 9000RPM - with decent gains and ran some of the SR20's with a cam conversion that saw the intake and exhaust cams change places together with the heders and intake manifold to reverse flow through the motor - this put the intake manifold at the front of the car and made for a better airflow scenario - HOW? I wish I knew, but I know it entailed the motor being mounted at a 15degree angle....


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