Jimmy-D

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

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

s2ktaxi

my understanding is you need X51 for that

Peter_GT4

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

cox1974

Perfect!

CAlexio

Very simply, yes. I did the mods sequentially and each step was noticeable. when entire system breaths better engine really changes character.. feels like a full bodied race car engine.

cox1974

sounds cool... ;-)

Voyager6

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

Accel Junky

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.

BGB Motorsports

The intake mods will give the most gain above 5K RPM. The tune will massage things but it will also allow you to turn off any annoying CELs that come as a result of any modification. As a complete package it's a really nice upgrade.

Agreed. The headers pick things up down low and the rest of the stuff delivers what you want up top. Just remember that the motor is nothing more than a big air pump; the more air you deliver and the more exhaust flow you enable, the more power and torque you will have.

Here's the thing...Suncoast is wholesaling and we are retailing a kit that when pieced together, far exceeds the price at which it's being sold. I did just as you suggested and had my heads ported and purchased the intake cams because i dont have a lot of capital to put into the car. A good head job will run as much as $2500 from anyone who knows what they're doing; while you have the cost to remove the heads that you would if upgrading to the X51 you also have the downtime associated with shipping them out and the shipping costs AND the risk of damage in transit. If you lay out the pieces, when you buy an X51 kit you get 2 complete cylinder heads with valves, valve springs, fasteners AND EVERYTHING all new from Porsche. The intake cams ran me about $3K (wholesale) and the most overlooked part of the equation is the brushed aluminum intake manifold that costs $5K when purchased by itself. The heads would be about $6K each to purchase I would think. I come up with about $20K worth of parts for $11.5K.

Agreed. I just wish you guys were closer and could drive my car with the complete Stage II. Every GT4 owner that has driven it has left obsessed with that top end pull over 5K RPM; the GT3 owners that drive the car are shocked and blown away!

Voyager 6 is always finding the awesome deals! I think that was the right call because i too wonder how long these parts will be available. We are trying to take full advantage right now as it is. Good update Greg!

I can't agree more. The intake upgrades are essentially worth their weight in gold over 5K RPM; the longtube manifold was designed to deliver torque down below because we could find several other ways to increase top end HP via pulleys, oil, mufflers, etc.


____________________________________

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!

Voyager6

John, The X51 kit was a good deal, but it blew my salvage car plans for a few months. There were a bunch of flood Caymans on the market in the last couple of weeks. Sad to miss out on them, but i'll get one eventually.

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

CAlexio

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.

legin

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.

cox1974

Thanks guys for your help...

kahane18

AGREED!!!