GT4 - Unlocking the Power Potential!
#856
Race Director
I have all that you mentioned just different tune and did not install the filters. I found the headers really helped the low to mid range torque and the 82mm and tune really helped the upper rev range. Faster to redline and power all the way to limit. Now, my problem is I did the tune and 82mm so I still do not know if the tune really made any difference but because I have never pulled a CEL and the engine feels really smooth than some thing had to attribute to that.
But - make no mistake - the Headers is where you feel the most obvious gains. Best bang for the buck no doubt. If your expectation is set too high you may be a little disappointed because the tune and TB is not as obvious as Headers
But - make no mistake - the Headers is where you feel the most obvious gains. Best bang for the buck no doubt. If your expectation is set too high you may be a little disappointed because the tune and TB is not as obvious as Headers
#857
Rennlist Member
Thanks mate.... i installed the headers 8000km ago.... now i'm curious if the plenum, the 82mm tb and the tune can give more "life" at the upper rev range
#859
I did it the other way round - first step IPD and 82mm throttle body/no tune, then the CG sport header along with a tune in the sedond step three weeks later.
Step one defintely added really noticeable live from maybe 5.000rpm to redline with very nice rev-out, no longer the stock "dead" and a bit lazy feeeling above 6.500 if you know what I mean.
Headers and tune later added a stronger base as described above to make the package completely sound. I assume you will get what you´re looking for.
Peter
Step one defintely added really noticeable live from maybe 5.000rpm to redline with very nice rev-out, no longer the stock "dead" and a bit lazy feeeling above 6.500 if you know what I mean.
Headers and tune later added a stronger base as described above to make the package completely sound. I assume you will get what you´re looking for.
Peter
#860
Rennlist Member
Perfect!
#861
Race Director
Originally Posted by cox1974
Thanks mate.... i installed the headers 8000km ago.... now i'm curious if the plenum, the 82mm tb and the tune can give more "life" at the upper rev range
#862
Rennlist Member
sounds cool... ;-)
#863
Might want to check to see how long the X51 kit will be available. Suncoast had a Pre-thanksgiving closeout sale on it (full 991 kit) for $2K off normal price and I called and they told me at that time, there were three kits left in the USA and only one without 991 headers. Mine is at local freight terminal, waiting for my pickup.
Now, that may be the 'official kit' and individual parts may be still available at increased price.
V6
Now, that may be the 'official kit' and individual parts may be still available at increased price.
V6
#864
I've been thinking about this...the X51 swap is big money. Couldn't you get the GT4 heads ported/polished with cam upgrade and come out with less money and more power? This car desperately needs that top-end straightened out.
#865
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Thread Starter
I have all that you mentioned just different tune and did not install the filters. I found the headers really helped the low to mid range torque and the 82mm and tune really helped the upper rev range. Faster to redline and power all the way to limit. Now, my problem is I did the tune and 82mm so I still do not know if the tune really made any difference but because I have never pulled a CEL and the engine feels really smooth than some thing had to attribute to that.
But - make no mistake - the Headers is where you feel the most obvious gains. Best bang for the buck no doubt. If your expectation is set too high you may be a little disappointed because the tune and TB is not as obvious as Headers
But - make no mistake - the Headers is where you feel the most obvious gains. Best bang for the buck no doubt. If your expectation is set too high you may be a little disappointed because the tune and TB is not as obvious as Headers
Might want to check to see how long the X51 kit will be available. Suncoast had a Pre-thanksgiving closeout sale on it (full 991 kit) for $2K off normal price and I called and they told me at that time, there were three kits left in the USA and only one without 991 headers. Mine is at local freight terminal, waiting for my pickup.
Now, that may be the 'official kit' and individual parts may be still available at increased price.
V6
Now, that may be the 'official kit' and individual parts may be still available at increased price.
V6
I did it the other way round - first step IPD and 82mm throttle body/no tune, then the CG sport header along with a tune in the sedond step three weeks later.
Step one defintely added really noticeable live from maybe 5.000rpm to redline with very nice rev-out, no longer the stock "dead" and a bit lazy feeeling above 6.500 if you know what I mean.
Headers and tune later added a stronger base as described above to make the package completely sound. I assume you will get what you´re looking for.
Peter
Step one defintely added really noticeable live from maybe 5.000rpm to redline with very nice rev-out, no longer the stock "dead" and a bit lazy feeeling above 6.500 if you know what I mean.
Headers and tune later added a stronger base as described above to make the package completely sound. I assume you will get what you´re looking for.
Peter
____________________________________
It sounds like everyone is pretty happy with their packages that they have created. I always liked the Mr. Potato Head approach to modifying where you can do things in succession. Obviously i threw the kitchen sink at my car because i'm in the business of marketing our upgrades. I think the stock car is impressive but I also know the true potential. I really wish you guys could have driven the Stage III Boxster Spyder. It was awesome, truly unreal. I wish the owner was on Rennlist and could speak first hand as to the car and its performance. Cheers everyone!
#866
The X51 kit arrived yesterday. Huge box. I plan to open it up tonight and photo if I get home from work before dark. Full skid, three foot tall box. Almost as big as the box that my 3.8L engine came in, but not quite. It must have a foot thick of Styrofoam insulation around the parts.
If someone wants the X51 kit, do it now before it gets to be too late. John and BGB are the perfect people to do this for you.
V6
#867
Race Director
i am surprised sometimes after so much time, at how much overwhelmingly positive feedback on the intake/exhaust mods for this engine, and yet how much hesitation there still is. This should be a sticky thread somewhere.
"For very little money, you can have a still very street-friendly GT4/Spyder with what feels like a racey engine which breaths fully and has much more power and torque from low to high rpm, just by changing to sport headers (I'm brand agnostic) and adding the intake mods.. don't think.. just press "purchase".. there is literally no performance compromise.. it's ALL better.
"For very little money, you can have a still very street-friendly GT4/Spyder with what feels like a racey engine which breaths fully and has much more power and torque from low to high rpm, just by changing to sport headers (I'm brand agnostic) and adding the intake mods.. don't think.. just press "purchase".. there is literally no performance compromise.. it's ALL better.
#868
I have taken the plunge so the message is getting through although Im starting with just intake and tune as it might be all im looking for. If not i will go to headers as well. I doubt I need the x51 as my 997 x51 was only 408 bhp anyway.
#869
Rennlist Member
Thanks guys for your help...
#870
i am surprised sometimes after so much time, at how much overwhelmingly positive feedback on the intake/exhaust mods for this engine, and yet how much hesitation there still is. This should be a sticky thread somewhere.
"For very little money, you can have a still very street-friendly GT4/Spyder with what feels like a racey engine which breaths fully and has much more power and torque from low to high rpm, just by changing to sport headers (I'm brand agnostic) and adding the intake mods.. don't think.. just press "purchase".. there is literally no performance compromise.. it's ALL better.
"For very little money, you can have a still very street-friendly GT4/Spyder with what feels like a racey engine which breaths fully and has much more power and torque from low to high rpm, just by changing to sport headers (I'm brand agnostic) and adding the intake mods.. don't think.. just press "purchase".. there is literally no performance compromise.. it's ALL better.