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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.
Nice delta on the dyno graph. I really like how the 4,800rpm dip is smoothed out. Is this an Evolve Technik package? or is it a headers/tune done by Fitzgerald's in house? How much all up was it fitted?
So you gain roughly 15 RWHP across the power curve (on a real 300 to 320 RWHP car), the peak value is a typical tuner switch (and only occurs over 400 rpm) and you have voided your warranty. 9k for a voided warranty and a 15hp gain .......... You would have gained far more doing driver training.
Also I note the base run was done on a different day and the car wasn't run to the redline.........
Wow!!!!- great results indeed. I have my headers going on next week and also a valveless exhaust. Do you think the valveless exhaust would remedy the annoyance you have when the valves open?? I figured I would always hit the exhaust button so made sense to always have it on
So you gain roughly 15 RWHP across the power curve (on a real 300 to 320 RWHP car), the peak value is a typical tuner switch (and only occurs over 400 rpm) and you have voided your warranty. 9k for a voided warranty and a 15hp gain .......... You would have gained far more doing driver training.
Also I note the base run was done on a different day and the car wasn't run to the redline.........
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?
Hi Jim, dynos vary quite a bit in their base results. The important part to focus on is the delta comparison between mods. With respect to torque, this wasn't plotted on the graph, but can be calculated using: Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM). I might plot this in excel in some point just out of curiosity, but it will take quite a bit of transposing to get the curve right.
Originally Posted by Charliekay
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?
I haven't noticed any yet. I had a 3 hour drive down to Hobart from Devonport yesterday and didnt pick any up. Will keep an ear out for it though and post back any feedback.
Originally Posted by Quack
Nice delta on the dyno graph. I really like how the 4,800rpm dip is smoothed out. Is this an Evolve Technik package? or is it a headers/tune done by Fitzgerald's in house? How much all up was it fitted?
Cost as mentioned below was 8.5k all in (headers, ceramic coating, tune, fitment and dyno work). Evolve and Fitzgeralds are essentially the same company (two shops are located next to each other and have common ownership and employees), just that Fitzgerald does all their Porsche work and Evolve does the rest. Headers are Cargraphic sports headers, coating done by High Performance Coatings, tune is from PP Performance (Evolve / Fitzgeralds are local distributors of PP).
Originally Posted by randr
So you gain roughly 15 RWHP across the power curve (on a real 300 to 320 RWHP car), the peak value is a typical tuner switch (and only occurs over 400 rpm) and you have voided your warranty. 9k for a voided warranty and a 15hp gain .......... You would have gained far more doing driver training.
Also I note the base run was done on a different day and the car wasn't run to the redline.........
A remarkably uniformed post randr. I really have to question the motivation here? Why would you try to make other people feel bad about money they have spent? In any case, I'll give you the benefit of the doubt and tackle each of the points you have raised:
Firstly the chart is in kw, not hp. In the mid range, the 30kw difference translates to roughly 40hp. This is a massive gain in exactly the area I was looking for. If you read my comments below, I was not in any way looking for a peak gain, but got one of 22.5kw (30 hp). I have no complaints with this outcome, in actual fact this has far exceeded my expectations.
With regards to warranty, please refer to Australian consumer law. There is no such thing as voiding a warranty from modifications. In this case of a disputed claim, the burden of proof is on the manufacturer to prove that any modification has caused the damage, if they cannot, they must honour the claim.
I dont see how driving training will fill the torque dip that was annoying me on my street driving? I have zero interest in lap times or track prowess. If you have driven a GT4 you would know what I am talking about and why I would want to address it.
With respect to the dynos, they were done on different days as the work was done across multiple days.
At this point I should include a smarmy wink or sequence of dots, but I don't really feel comfortable playing down at the level you are lurking.
Originally Posted by Jimmy-D
Wow!!!!- great results indeed. I have my headers going on next week and also a valveless exhaust. Do you think the valveless exhaust would remedy the annoyance you have when the valves open?? I figured I would always hit the exhaust button so made sense to always have it on
Also - was this cattless??
Hi Jimmy. I think a valveless exhaust will exactly address the problem I am having with the stock PSE. Its the valves being closed choking back the power and then popping open at 4k rpms that is causing my issue. If you dont have any valves then I think you will completely avoid this. Will be interested to hear about your experience once you have everything fitted.
My headers are the sports headers with 200 Cell cats.
I am not trying to make you feel bad, and I know the chart is in kw - I calculated the power out as HP (e.g. 1kW is 0.746HP). Yes you have managed to dial out the dip before variocam plus is fully active (did you ask your tuner to explain why that dip exists? do you know why that dip is produced by all NA Porsche engines? do you know how and why variocam plus works?). The actual real power gain is an integral of the area under the torque curve, you can't cant just cherry pick the bits you like (power is directly proportional to torque and rpm and thus its the area under the torque Vs rpm curve that defines the overall benefit).
The peak power is in effect a transient blip - for it to be more than that the whole curve has to lift in line with the peak - not locally lift. Moreover you need to see this in the context of GT4 dyno runs which vary from ~ 300rwhp to 320rwhp (on MAHA dynos that measure run down losses).
Anyhow if you're happy, I'm happy - however, I (and many others) would question the loss of warranty for what is in essence a relatively minor gain - good luck with Australian consumer law - this is what will happen if your engine goes bang. Porsche will say you modified the car outside of specification by changing key components including the ECU (and they will be correct), they will use these posts to prove you modified your car and you will attempt to prove some form of defect and will lose. Its been tried many times.
For reference I hold two CAMS I class licences - honestly, if you had put the money into high performance driver training you would have gained a far greater benefit. Believe it or not this is good advice and is well meant Apologies in advance for my curt delivery.
I am not trying to make you feel bad, and I know the chart is in kw - I calculated the power out as HP (e.g. 1kW is 0.746HP).
1 kw is in fact 1.34 hp - you got the conversion inverted.
Originally Posted by randr
Yes you have managed to dial out the dip before variocam plus is fully active (did you ask your tuner to explain why that dip exists? do you know why that dip is produced by all NA Porsche engines? do you know how and why variocam plus works?). The actual real power gain is an integral of the area under the torque curve, you can't cant just cherry pick the bits you like (power is directly proportional to torque and rpm and thus its the area under the torque Vs rpm curve that defines the overall benefit).
The peak power is in effect a transient blip - for it to be more than that the whole curve has to lift in line with the peak - not locally lift. Moreover you need to see this in the context of GT4 dyno runs which vary from ~ 300rwhp to 320rwhp (on MAHA dynos that measure run down losses).
As you state, the benefit is the total area between the two curves. The area between these two curves is significant, and it translates to a considerable performance difference to the car. Having said that, I was not actually looking for this considerable performance increase (the car is fast enough).
What I was looking to do was to remove the dip that takes place in the mid range, and have achieved this (with no sacrifice anywhere else in the range). Again if you have driven a GT4 you would understand why. I have driven many different Porsches and none have suffered to the extent that the GT4 does in this area. IMO 8.5k is a small investment to achieve this, for others it may not be.
Originally Posted by randr
Anyhow if you're happy, I'm happy - however, I (and many others) would question the loss of warranty for what is in essence a relatively minor gain - good luck with Australian consumer law - this is what will happen if your engine goes bang. Porsche will say you modified the car outside of specification by changing key components including the ECU (and they will be correct), they will use these posts to prove you modified your car and you will attempt to prove some form of defect and will lose. Its been tried many times.
Lets agree to disagree on warranties (and also the minor gain). For information, the tuning shop includes a one year warranty on the driveline with the tune, but I would have done this even if they didn't. Everyone has different risk profiles (and ability to pay for any consequences), I'm very comfortable with this decision.
Originally Posted by randr
For reference I hold two CAMS I class licences - honestly, if you had put the money into high performance driver training you would have gained a far greater benefit.
You really dont read very well. I have no interest in track times, and driver training would in no way address my goal, which is to improve the mid range power delivery of the car.
Originally Posted by randr
Believe it or not this is good advice and is well meant Apologies in advance for my curt delivery.
Its not good advice because it does not actually address my issue, which you would know if you took the time to read what I wrote properly. It was also not curt delivery, but words delivered with knowing winks - an attempt to big note yourself at someone else's expense.
Some advice back to you, when you write something down in an internet forum try to think of how you would feel if you read what you put down in 10 years time. If it makes you cringe, don't post it.
I am not concerned about warranty when I mod which is going to be very similar These mods are really not too extreme and the engine coming from the Carrera S is pretty stout. Enjoy the heck out of it. My Dealership is actually doing my mods and mine are all coming from FVD which is as close to Porsche as you come.
If some one is against mods just do not read these threads- quite simple. There are threads I do not read nor participate because not inteested
Whats the go with the GPS in our cars, they're are not that good, I used it twice and both times it took me off direct route. Ran my phones google maps at the same time which was reliable without any issues.
Jim - I run one of these and Google Maps. It's a Belkin Cup Holder mount. The way the Cup holders have that little pop out means it works very neatly IMO.
I mostly got it to hold the phone for my lap timer when I'm on track but I find Google Maps is better than any car nav so use it as a preference anyways.
[QUOTE=Snowman.;13423991]Jim - I run one of these and Google Maps. It's a Belkin Cup Holder mount. The way the Cup holders have that little pop out means it works very neatly IMO.
I mostly got it to hold the phone for my lap timer when I'm on track but I find Google Maps is better than any car nav so use it as a preference anyways.
QUOTE]
Thanks Andrew, what a great idea, where did you get it from?
Cost as mentioned below was 8.5k all in (headers, ceramic coating, tune, fitment and dyno work). Evolve and Fitzgeralds are essentially the same company (two shops are located next to each other and have common ownership and employees), just that Fitzgerald does all their Porsche work and Evolve does the rest. Headers are Cargraphic sports headers, coating done by High Performance Coatings, tune is from PP Performance (Evolve / Fitzgeralds are local distributors of PP).
Thanks for that. 8.5K is pretty reasonable for the gains. I did leave a message with Fitzgeralds to call me back about zorst and tune, but they never got back to me. I will keep them in mind. So many different options!!!!
Jim - I run one of these and Google Maps. It's a Belkin Cup Holder mount. The way the Cup holders have that little pop out means it works very neatly IMO.
I mostly got it to hold the phone for my lap timer when I'm on track but I find Google Maps is better than any car nav so use it as a preference anyways.
I picked one up from a phone shop at Southland. I knew what I was looking for and just went in to all the shops until I found one that had it. From memory it was an Optus shop but I have seen them around in many of them.
07-02-2016, 08:57 AM
You would have gained far more doing driver training. 
