IanM

I thought I'd post some dyno results from today.

I just had the coolant fittings welded, and I thought it would be interesting to have my new (to me) '04 GT3 dynoed. Previous owner had installed FVD headers, FVD ecu tune, Europipe exhaust, RS flywheel / clutch / front pulley.

The pulls were made on a Dynapack dyno. Results were 355 rwhp and 265 lb-ft torque. A stock 996 GT3 on this dyno had previously made around 340 rwhp. I'm not sure how these results compare to others on the board, but the shop owner seems to think my motor is running strong. The a/f ratios looked conservative, low 12's measured downstream of the cats. If measured properly (upstream of the cats) the numbers would have been slightly more rich.

Serge944

Looks typical and healthy!

964C4

So all these nice mods yield only 15hp ? I though Europipe alone gains 12hp; headers 5-7hp and ECU tune around 10hp

I ask this, because I did simmilar mods but I am expecting 20hp at least...

kk2

Looks like right under 400bhp after mods. 340whp stock is a 12% drivetrain loss.

Sounds about right. 400bhp is definitely healthy for a 3.6l.

kk2

The 7.1 is rated at 415bhp. That extra 15bhp can be attributed to the heads, cams, and intake.

The exhaust and pulley probably gave you the extra 15hp. The tune just gave a better powerband.

IanM

The shop owner feels there are more gains to be had if I dump the cats, which are high flow but still a big restriction. Unfortunately we have smog testing where I live, and I can't be bothered to swap out straight pipes. Besides, the power is good and I don't want the car any louder.

I just found out that previous stock GT3 made about 335rwhp on the Dynapack, not 340. So I guess my mods are worth a bit more, about 20rwhp. If 335rwhp equates to 380bhp, that puts me at just a tick above 400bhp. I know, just numbers, but bench racing can be fun.

kk2

I doubt getting rid of the cats would do much for you.

996FLT6

^20lbs dead weight off at the very end of car if u go cat bypass. Thing with any aftermarket exhaust system as long as its lite and no loss of power thruout the powerband hp/Trq. Getting liter is what get these cars running : )!!!! Mike

IanM

After reading all the scepticism regarding the IPD intake plenum and 82mm 997 GT3 throttle body mod, I decided to buy it anyways. I recently took the car back to the same Dynapack dyno and same dyno operator who tested the car almost exactly four years ago. No other mods have been made since 2012 (still have the FVD headers/tune and Europipe exhaust).

Yes, I fully recognize that four years have passed since the last dyno test, and comparing results is not exactly apples to apples. However, it's all that I've got and the results do show impressive gains.

In talking with the dyno operator re: the 2012 results, he noted an erroneous 'kick' at the top of the pull that produced the previously reported peak 355hp and 265 ftlb torque. He advised that from my 2012 dyno session, the most representative peak run shows 345hp and 362ftlb.

Now onto the latest results w/ IPD and 997 GT3 throttle body. My car now pulls 362hp and 285 ftlb torque, a peak increase of 17hp and 23 ftlb. From the plots, it's making more torque and hp everywhere, and it now making an extra 30hp to the wheels at 6000rpm. At a 12% drivetrain loss, it's now around 411hp.

I'm happy with the results, and last Saturday shaved 0.5 sec off my PB at Ridge Motorsport Park. Even with the inevitable discrepancies between the 2012 vs 2016 dyno session, I'd say that on my car, with my other supporting exhaust mods, the plenum and throttle body are showing positive results.

Also fyi, the air:fuel ratios weren't impacted so I'd say a retune is not required for this mod. My car is showing low 12's at redline for both sets of dyno runs, measured downstream of the cats. The dyno operator says that equates to high 11's upstream of the cats, which is definitely on the conservatively rich side. He figures we could unlock more hp with a custom tune. I'm getting custom cat bypass pipes fabricated next week, will likely put her back on the dyno after that, and will look into the custom tune option.

IanM

a few photos of the plenum. A bit of a pain to install, I had to remove the oil filter housing.

Charles@dundonmotorsports

Interesting results. My personal experience with one on a stock 996 GT3 had some gains and some losses up and down. This was 7 years ago. I have not tried one since but might be worth while combined with my exhaust.

One thing I do find curious is that the torque peaks no longer line up. Last time I saw this on my friends dynapak was something with the gearing that wasn't Correct so it wasn't calculating rpm correct. Just curious to Me.

Looks like blitzkerig, so I'm sure Cheyene has it all setup right.

IanM

You're right Charles, I did a re-gear last year, am now running shorter Guard 3/4/5, with my old stock 5th gear in the 6th gear position.

Charles@dundonmotorsports

Go back and have him re correct the gear ratios

996FLT6

Dynod longtime ago at Mce engineering at Thill waiting in between sessions at Nasa NorCal on a dynojet. Mods were fab muffs with cat bypass/lwf/4.0 rp. Have no clue what's the difference between dynapack or dynojet. Mike

KOAN

I was at 365 hp 273 lb/ft with a lwfw an Europipe a few years ago. I put on a 997.2 cup exhaust and will retest this Spring. I have been told different dynos are not comparable.