.dee

Hi Warwick, thanks for this, have been following your progress, for reference we did a twilight drive back in December with track temps around the 40-42! and speeds at the end of the straight were in the 220-225 range, stock and gps verified.

whats sort of times were you putting down with your current set up?

p.s. i have removed the swift springs, although the car was better before approx. 1-2 sec per lap on the GP circuit, i could not get it up the driveway...

Warwick Morris

Hi .dee, my speeds were 10 hz GPS and I've not seen over 223. We were running on the North circuit on Saturday in a BMW Club sprint event. My best was 1:11.98 and I came 6th out of 52. 5th was a 991 GT3RS with a 1:10.77. The top 4 were race cars. My best at the GP circuit on a track day with 100% stock was 1:47. The car is quite a bit slower than my old 996.1 GT3 which has run a sub 1:42 but it is what it is. I'm going to try some Trofeo R's which the Victorian guys say work well at PI and they did a good job at Bathurst last November. I am going to run the car in this year's PCNSW Supersprint series and it would be good to run against some other GT4's.
I'll stick with the TB and IPD for a while though it seems to add zero at present.....might be interested in your springs though if you want to PM me.

.dee

Thanks Warrick, I ran a low 1.46 with the springs on a stock car otherwise and 1.47-1.48 without on the GP circuit, the car feels much better with the springs with little to no under steer, but it is approximate an 1" lower, which is my issue.

I am going out on Wednesday morning with the CPC guys to get a few laps in before heading off OS, the only difference in the current set up to the earlier one are the rear offset toe links (allowing -2.0 Camber) and front (Medium) and rear (Hard) sway bars.

re: springs you can have them for 50% ($500) if you want

mrd_spy

have you got a tune as well or jus the IPD hardware with no tune file ?

BRNGT4

My experience is not that great with modding my GT4. Currently have cargraphics race headers, IPD plenum, 82mm throttle and tune (Tune came with the package). Dyno at 368whp. Top speed on the main straight is within 2kph of when the car was stock (using aim datalogger). My conclusion is that the mods dont work.

RealityGT

Def go for a retune.. Your location can't be easily accounted for with a canned tune.

Hope you find the results you were looking for. GL

cox1974

how much are at the crank?

sunnyr

Didn't shakenbake also post that his car with mods wasn't faster than a stock car on the straights?

Warwick Morris

No tune but the OEM ECU should be able to use the additional air supply. My conclusion at this stage is that best improvement for lap times would be to fit cup brake calipers and 18 wheels so that proper competition R-Spec tyres can be fitted, this would be followed by a higher FD.

CAlexio

Correct me if I'm wrong, but I believe Cobb had come online to say that the stock ecu wouldn't maximize the increased air supply.

stout

Two areas of performance:

1. Peak performance/peak power (hp, top trap speeds, 0-60, etc)
2. Drivability, which can increase pleasure in use as well as cumulative speed

Sounds like BRNGT4 isn't seeing improvements in #1 to merit the expense. Sadly, that's par for the course with a lot of aftermarket gear. Whether or not a tune would improve his findings, I have no idea. I have been told by someone in the factory that the X51 plenum needs work to fit in the GT4 but does not need a tune to be taken advantage of. Still waiting to hear back about headers + plenum.

All a lot of speculation until there is better data.

Now, about area #2, driveability...that is much harder to document, but it can make ALL the difference. One race car can generate more g around a skidpad, and be lapped on track by a car with less grip in outright terms. This is true in every area of a car's performance...

neanicu

John at BGB motorsports was kind enough to briefly explain those modifications : as I understand it,the plenum interferes with something that it's part of the body,so some material needs to be removed/modified and there's also an issue with the coolant reservoir's location. It certainly didn't sound like a major fitment issue that Porsche led us to believe.

CAlexio

Working in the medical field, I'm all too familiar wth placebo effect.. human brain has a crazy way to make itself belief something it thinks it should believe. So maybe after we spend $ on mods we want to believe will work, then we actually feel them working. Maybe.

But I challenge anyone with a regular spyder or gt4 to get into mine and not feel a massive difference from stock. 'UUGE difference from stock. Before it was strangled, now it's an animal. Smoothness, torque fullness, lugging from lower gears it just continues to pull all the way to redline, let alone the increased volume after 4K rpm. It has made the car immensely more enjoyable to drive. So.. even if it's only Stout's #2 which changes, I still have zero regrets and would redo it all over again, especially considering how easily reversible everything is. but I'd be really surprised if #1 didn't change also.

bretster

What setup are you running CAIexio? I looked through the thread but could not find it.

stout

Yes, I think there is something to that. And good on your for admitting it. A lot of people can't, especially after spending money on a product. Exhaust mods are one of the biggies that do this for people, along with intakes: It's louder > It's faster.

To me, a real and noticeable improvement in #2 is enough to spend $$$ to $,$$$ on, and maybe even $$,$$$. Unless I am racing, which I am not in a street car, qualitative matters more than quantitative. I remember driving a hot-rod air/oi-cooled 911 years ago with a big dollar engine ($50k or some such) that didn't feel fast. It was fast, but it didn't feel fast. It felt about as quick as a stock US 993 (which feel good but not "fast"). In a perverse way, it was kind of an incredible achievement, but talk about a bummer: The car could get you in big trouble with the law, but somehow wasn't any more fun than a stock one, and was 2x the price of another car like it.

Of course, if one is chasing lap times, #1 matters—but if #2 improves driveability, usability, or driver confidence, it can have same or greater effect than gains in #1—especially if #1 gains come with sacrifices in #2.