Australian GT4s
07-15-2016, 06:50 PM
#556
Instructor
Anyways - OT - following on from Brads post a week or so ago a few of us have decided to get some of the Cargraphic headers. I've arranged a discounted price through a local supplier (10% off rrp) since there is a few of us getting some.
If anyone else is interested in getting in on this let me know and I'll send you the details.
07-15-2016, 07:08 PM
#557
Rennlist Member
Leong. Also consider the Dundon a motorsports headers under development for the GT4. I have done Tonnes if research for the GT3, spent months on it, these really are a hand crafted piece specifically developed on the jig and the dyno for the car. Nothing against CG as I've had their stuff before but the DMS stuff is just another level and the guy who designs and builds them a true engineer who experiments on the dyno and uses science to extract the best he can from the system. When you see them in the flesh your draw drops, I've been modifying Porsches for years and they are the most impressive I've seen having played with Fabspeed, dachX, CG etc. 123 stainless throughout equal length with much higher quality valves and fittings than the OEM. I can hook you up a favourable price. Just saying...
07-15-2016, 07:42 PM
#559
Rennlist Member
DMS have just posted today their initial dyno plots and video on the GT4. Very impressive. Its still a work in progress. Charles will not stop will he gets it right as always...
07-16-2016, 01:35 AM
#560
The main issue currently for us and the DMS gear is the lack of cats.
None of us currently in the CG group buy plan on getting a tune (at least in the short term). That won't be an option with catless headers.
None of us currently in the CG group buy plan on getting a tune (at least in the short term). That won't be an option with catless headers.
07-16-2016, 03:29 AM
#561
Rennlist Member
You can run the DMS race headers without a tune absolutely fine. Guys with the system say it rarely throws the check light. Some have never had it at all. If it does it doesn't affect the performance and they threw in an ODD2 tester for free to reset the code...
07-16-2016, 07:42 AM
#563
Three Wheelin'
Thread Starter
Yeah that was Mark (one of the guys getting headers). His car came the same time as Bardmans. (PCM)
I know the US deal was for 15% - but that was for far more numbers than Alvin has. (Currently 4 of us). That all said the price by the time it is landed here is about 15% less than Evolve quoted.
I know the US deal was for 15% - but that was for far more numbers than Alvin has. (Currently 4 of us). That all said the price by the time it is landed here is about 15% less than Evolve quoted.
Just kidding, you guys will be happy with the results. It sounds great, and really addresses that choky almost stutter that the base car does at around 3.5k when driving around town.Luckily they don't test emissions in NZ. I'm wont have tune either due to warranty issues. A cat version is around the corner.
You can run the DMS race headers without a tune absolutely fine. Guys with the system say it rarely throws the check light. Some have never had it at all. If it does it doesn't affect the performance and they threw in an ODD2 tester for free to reset the code...
You can run the DMS race headers without a tune absolutely fine. Guys with the system say it rarely throws the check light. Some have never had it at all. If it does it doesn't affect the performance and they threw in an ODD2 tester for free to reset the code...
For the race headers, I have also heard that they can smell bad, and that they can deposit soot on the back of the car (particularly a problem for white cars). You have more experience than me Macca - do you think this will be an issue?
Per my message Jim, sorry I couldn't make it, no doubt you guys will have a fun day.
07-16-2016, 07:54 AM
#564
Three Wheelin'
Thread Starter
There was a really good post from someone here on rennlist (I cant find it right now) about why you should break your car in. It to do with thermal expansion of the various components. I agree that 3000km is a bridge to far, however, we are only human!
Its also worth noting that AP was talking about people taking their cars directly to the track being a problem. Clearly tracking your car is far more punishment than the occasional run up to redline.
I ultimately followed something similar to what Jim mentioned, varying revs and load frequently with the occasional run right through the range.
07-16-2016, 08:02 AM
#565
Three Wheelin'
Thread Starter
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.
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.
I got an updated tune today and the exhaust problem has been completely addressed. The flaps open earlier so you don't get the exhaust gas build up and "blurt" as it is released. Power delivery is smooth, and you can really feel it when it comes on cam. Nice.
The only question now is, is the car now too fast? Maybe a good problem. Something to ponder before I head back.
07-16-2016, 08:08 AM
#566
Three Wheelin'
Thread Starter
One thing I will mention (I posted this in the cargraphics thread, but repeating here also). Make sure that whoever places the order with Germany stresses that the quality needs to be right. Both Gazza and I had problems with the headers not being flat where they fit the engine block. Gazza sent his back and I had to get mine machined. Read more in the cargraphics thread or let me know if any questions.
07-16-2016, 08:16 AM
#567
Three Wheelin'
Thread Starter
Ok, so a follow up to this post.
I got an updated tune today and the exhaust problem has been completely addressed. The flaps open earlier so you don't get the exhaust gas build up and "blurt" as it is released. Power delivery is smooth, and you can really feel it when it comes on cam. Nice.
The only question now is, is the car now too fast? Maybe a good problem. Something to ponder before I head back.
I got an updated tune today and the exhaust problem has been completely addressed. The flaps open earlier so you don't get the exhaust gas build up and "blurt" as it is released. Power delivery is smooth, and you can really feel it when it comes on cam. Nice.
The only question now is, is the car now too fast? Maybe a good problem. Something to ponder before I head back.
07-16-2016, 08:30 AM
#568
Rennlist Member
I've run cat less systems in my 911s for almost 20 years. The only car I don't currently is the GT3 but that's about to change. Interestingly the GT3 is the soot user of them all but it may be the white paint. A day at the track and you can write your name in the dust on the bumper. As for the smell, yes it may be a little stronger but I don't hang around much to sniff it. When I do it reminds me of the good old days driving my Triumph Herald 1360 when I was at Varsity :-).
The tune is useful for smoothing out the curves. Id like to add the tune as it makes more power and torque but I'm about to extend my warranty 2 years so feel an ECU flash might compromise that.
Now Jamie has the new facility set up I expect the catted GT4 version will be less than a month away. The GT3/RS version has been done but not productionised as there were still a few things that needed to be ironed out but the grunt work is done.
One thing I really like with the DMS system is it bolts right up to the factory third muffler and keeps the factory sound. Noise us around 20% louder with the valves open. I have been running the shark works bypass so expect it to sound around 5-10% louder than that which is just fine...with the valves closed its not really much louder than stick maybe 5-10%...
I'm unsure what the price would be. It's not s cheap system as it's made from a grade of SS you don't readily see used for this work due to the additional cost. They can make them from inconel or Ti if you have really deep pockets. I should think it would be comparable to the CG system for the catted version...
The tune is useful for smoothing out the curves. Id like to add the tune as it makes more power and torque but I'm about to extend my warranty 2 years so feel an ECU flash might compromise that.
Now Jamie has the new facility set up I expect the catted GT4 version will be less than a month away. The GT3/RS version has been done but not productionised as there were still a few things that needed to be ironed out but the grunt work is done.
One thing I really like with the DMS system is it bolts right up to the factory third muffler and keeps the factory sound. Noise us around 20% louder with the valves open. I have been running the shark works bypass so expect it to sound around 5-10% louder than that which is just fine...with the valves closed its not really much louder than stick maybe 5-10%...
I'm unsure what the price would be. It's not s cheap system as it's made from a grade of SS you don't readily see used for this work due to the additional cost. They can make them from inconel or Ti if you have really deep pockets. I should think it would be comparable to the CG system for the catted version...
07-16-2016, 09:41 AM
#569
Instructor
Ok, so a follow up to this post.
I got an updated tune today and the exhaust problem has been completely addressed. The flaps open earlier so you don't get the exhaust gas build up and "blurt" as it is released. Power delivery is smooth, and you can really feel it when it comes on cam. Nice.
The only question now is, is the car now too fast? Maybe a good problem. Something to ponder before I head back.
I got an updated tune today and the exhaust problem has been completely addressed. The flaps open earlier so you don't get the exhaust gas build up and "blurt" as it is released. Power delivery is smooth, and you can really feel it when it comes on cam. Nice.
The only question now is, is the car now too fast? Maybe a good problem. Something to ponder before I head back.
Nice to hear the exhaust valve issue has been sorted Bardman. Might have to call Fitzgeralds...
07-16-2016, 10:34 AM
#570
Race Director
Bardman - I am running the FVD Sport headers with valveless exhaust. I think the best thing I ever did was go valveless. The car is just pure sex the way it sounds and it is nice because there are no transitions.