cox1974

Here you'll find my old dynosheet with and without sport headers....
https://rennlist.com/forums/gt4/8964...l#post12885224

Now we will see the improvement with plenum, 82mm tb and Cobb protune by fabspeed

bhk1004

I've ran against a sport header exhaust and custom tune gt4 on a marked off 1/4 mile. My car completely stock. Rolling start side by side at 20mph~ I won 1 time, and other 2 time he had me by about 1/2 to 1 car length. So around 120mph. I think the sport headers make power way too low in the rpms range to make much if a difference when actually wringing out the car.

Yargk

I missed this post before, thanks for the information! Let us know when you get it dynoed with the other parts.

I can't understand why everyone who upgrades doesn't also do both before and after dyno runs.

Warwick Morris

I had an IPD and TB installed a couple of weeks ago and have registered for a Supersprint event at Eastern Creek in Sydney on the 4 Feb. I will be looking for increased main straight speed and will update after the event. I have data logs for the unmodified car. I also had rear toe links installed and a -ve 3 F and -ve 2.75 R set, so speed onto the straight will be slightly higher (hopefully) but still using MPS cups. I will let y'all know the outcome.

zmon

funny so many asking/saying its weird that there have been no numbers posted...

well why would a shop (any that are making parts for the GT4 and frequent this forum) waste the time and resources to share (or obtain) this info when plenty on this same forum are all in buying and said companies are selling out of product via group buy etc..

GT4_Driver

Well, to be honest: one of the most reputed German Porsche tuning shops told me that they have serious doubts about the alleged power gains by installing the IPD, TB etc. because none of the cars they had on their dyno achieved the alleged power. Therefore, I just wanted to know if anybody measured the acceleration of his GT4 after the tuning. It is kind of funny that, apparently, nobody does that. As I mentioned the a-Workx that was tested in SportAuto had allegedly 420hp, however, the acceleration measured by SportAuto was on the same level like the series GT4.

cox1974

Just finished to make datalogs for Fabspeed... Tonight i'll send them via email and wait for the custom ecu map.... I think that for the end of january/beginning of febrary ...i will dyno again my gt4 to see if my buttdyno works correctly... Fingers crossed...and stay tuned for the next dynosheet....
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Bardman

I too struggle with the lack of data that is put out there by those selling performance products. What I will say, however, is that 1/4 mile runs introduce so many variables that it makes valid comparisons difficult. A dyno done right will pretty accurately tell you what has changed with regards HP/torque, but 1/4 mile adds in additional variables like tyres (hot or cold), surface grip, how good was the launch, gear changes, wind speed etc. (I'm assuming temperature/humidity etc variances are equally bad between the two).

mrd_spy

it is a joke no figures are out there yet,

people quoting peak BHP at 2k revs is laughable, and Duddon, well what can you say, way over est power, they could back that up with a 40-120mph run before and after, but no, it's all about peak BHP at stupid revs !

but atm with no data it's poor, 1st thing I do with any car is performance box the stats from 2nd gear pull at 40 mph to red line in 3rd, gives one a good graph and figures to play with as a benchmark. also 40 mph to red line in 3rd is very doable time after time.

1/4 mile is pointless and too hard on the car.

mrd_spy

no one cares about dyno sheets anymore, we have all seem them time and time again

even fabspeed are out there quoting peak BHP at stupid revs one will never see !

there manifold gave less bhp where you wanted it !

cox1974

but you see always vendor's dyno sheets... mine measurements are from a "normal gt4 owner" from Italy...i'm a lawyer in real life.... not a seller/tuner....
i always use the same dyno from the same tuner (autech.it)... not affiliated with anyone....
if you want to see indipendent and objective data this is the only way imho.....

RealityGT

Not entirely correct. In this instance there is no need to "cut the light". You could sit on the tree for an hour and it wouldn't alter the #'s you would produce. You simply need to use launch control and shift ... roll down the strip and collect your slip. RT is irrelevant in this case.

RDCR

Yep, it would nice to see some real world, useful gain info from these mods.

konaforever

Leave it in auto?

RealityGT

HAHA OOOPS!