I got my car back from its PP wrap today, plus I also put ClearPlex on my windscreen again for full protection. Very happy with the results.

 

Early morning drive sounds good, I really enjoy driving through the really tight twisty bits.

As a matter of fact I'm getting together for a drive and breaky with some friends this Sunday, we currently have my GT4, Cayman GTS, Audi R8, 3LCarrera, Suby WRX, a couple more might turn up as well.

2 or 3 more cars would be welcome if anyone is interested. Let me know if anyone would like to join in.

Meet at 8am in Mt Martha, I'll pm address on request.

 

Dammit, I'm on the boat now, about to head back to Tassie. Would be good to do more of these drives, its difficult to drum up enthusiasm in Hobart, but we do get the occasional drive day in.

Enjoy the drive in your new car.

I'll write another post on the headers and tune.

 

I was pretty blown away to be honest. I was not really expecting any peak gains (or only minimal) - was really looking to flatten out the dip and hopefully add some more sound, but it totally exceeded my expectations.

Yes it is.

Sound is awesome. Really puts out a lot of sound when you are getting into it, but is still very comfortable when just cruising around.

Thats with the tune as well as headers.

In the next post I'll write a more detailed summary of my thoughts.

 

I may have a bi-annual lap you can join in if you are an "enthusiastic" driver.

 

I'm always up for it.

 

FWIW - I know of a bunch of GT4 guys who have entered the Bathurst Sprint in Novemeber (including me). I'm also 95% in for Targa High Country (either just the tour or maybe GT Sports) as well.

 

Ok, so my thoughts on the Cargraphics headers and tune from Fitzgerald Racing (Evolve sister company).

To put it very briefly, almost perfect. I'll get to the almost part, but this is a fantastic mod for the GT4.

I still don't have the electronic dyno pic, so I just took a photo of the paper one so people can get a clearer picture of what these changes have done (apologies for potato quality).



So, bottom line is stock power curve, next one up is headers only, and next one up is headers and tune.

Whilst the headers alone did flatten out the curve somewhat, the headers and tune has completely eliminated that mid range dip. You'll also notice that there is quite a lot of white space between H+T vs stock. You immediately feel this on the road.

Whereas the stock car feels like its strangled down low, the car now just pulls and pulls all the way through the rev range. You might think that a mod like this would make a car less civilised and harder to live with day to day - the complete opposite is the truth. Because you are not navigating up and down the mid torque dip (which you do constantly in street driving) the car is extremely easy and comfortable to idle along slowly. I even find myself running in a higher gear than previously when driving slowly as I dont have to keep the revs super high to avoid this "chokey" range.

So, some might be concerned that its all too tame. No fear of that. Plant the foot and it absolutely screams towards redline. It actually reminds me a little of the pull of my old C63. Of course it doesn't have anywhere near that amount of torque, but because you don't have the traction issues of the C63, it actually feels like you are applying similar levels of torque to the road. I'm probably overstating it there as I'm sure if you drove them back to back it wouldn't be as impressive, but it is an amazing feeling nonetheless.

What about the sound? Its really hard to estimate how much louder the car is now at full noise. My best guess is somewhere between 25 and 50%, but that is purely a guess. The good news again is that you have choices. With the sports exhaust button off, you can rev through the range and it doesn't sound significantly different to stock. Reasonably civilised, but still a bit noisy if you have the right foot into the carpet. Sports exhaust button on, and just taking it easy and again, the car is a bit noisy but not over the top. WOT in the high rev ranges, however, and it sounds like a motorsports car. It has a really rich sound (not at all spoilt compared to the stock sound), which really resonates under overpasses and bridges. You'll like it.

One thing that I didn't really understand before this mod was the claims by some tuning houses about the gains to be had by replacing the stock exhaust/mufflers with their own. If you have sports or race headers I totally get it now, and here we get to the 'almost' part of 'almost perfect' that I mentioned at the beginning. The stock exhaust, even with the sports exhaust button activated, does not actually keep the valve open all the time. It opens it according to the current rpms and throttle position (and maybe other factors?). So whats the problem then? Well because you have so much more exhaust flow due to the headers and tune, when the exhaust valve opens it feels a little like popping a cork. At around 4k rpms with only moderate throttle the exhaust valve opens and you get a blurt from the exhaust and the car literally takes off, there is so much latent power being restricted by the valve. You dont get this at WOT as the valve opens earlier, but at part throttle you get it, which is a little bit of a niggle for me, as at part throttle you want things to be smooth, not 'twitchy' as you navigate forwards and backwards over the 4k rpm range.

I have discussed this with the tuner, and they are going to look into a change that just keeps the valves open all the time with the sports exhaust button on. I think this will be the perfect solution, as you can still have the car tame if you want by switching the button off.

In any case, I'm confident they will sort this out. For some it may not be a problem, but for me this car is so close to perfect that it would be a shame not to address this little niggle.

In short a magnificent addition to an already amazing car.

Happy to try and answer any questions people might have.

 

So the obvious question is, what is the ball cost for what you've done?

Also can you reflash it yourself if the dealer wipes it with a software update, or do you have to take the car back?

 

BTW - applied some decals I bought online (Porsche on the wing as well).



I think the design is right, but a light grey or maybe a silver will look better. I kind of knew once they arrived that they would be too white, but decided to try them anyway.

 

Roughly 8.5k all in (headers, ceramic coating, tune, fitment and dyno work). It took them some extra time as this was the first one they have done, but they wrote off quite a bit of their time against R+D also.

 

Thanks for the write up on the mods Brad. Seems like a really impressive change to make.
Pity we couldn't catch up. Next time you are in Melbourne yell out.

Cheers
Chris

 

Brad
Great write up, I can really sense your excitement and how satisfied you are, well done. As Chris said we'll have to catch up next time.
I'm really surprised at the low stock power at wheels, I always thought you loose around 20% from crank to wheels but this equates to a larger difference, do you happen to have the torque figures, before and after?

 

Great writeup mate, the headers and tune looks like it is definitely on the cards.

Any drone coming from the new headers at any speed/cruising?

 

On a dyno dynamics that's about what I'd expect, 20% would be more dyno jet or getting into hub dyno territory.