Charles@dundonmotorsports

I have a pile of parts to test on 996 GT3's (or one single one just for testing) I just have to have the time to do so. I have been working backwords with all of the packages for these cars, and I have stuff to do on the 6-3 and a lot of parts to test, just have to get to it. CUrrently on the 6-3 other than my exhaust setups (dual and single exit, and 2 different header lengths) I have 2 different other intake manifold/plenum options, I want to test the IPD, and I also want to try my 2 other setups to compare, as well as my other air box, and then I have 2 sets of cams (one is just intake cams, other is intake and exhaust) to test. on the 997 3.6 gt3 I just have to head back to the dyno to test the current setup, but expect a full 40whp gain over stock after a quick tune, (359whp---> 400whp?) so I am hoping for similar gains on the 6-3, should be able to go from 355whp --> 390whp. I'm up over 40 on the 3.8 now, then once done with the 3.8RS, i'm going to finish the 3.6rs, then the 6-3

Cheyne

I have no horse in the race on this but if anyone wants an IPD plenum and throttle body for their 996 GT3, i have one that is just about brand new which I will let go for half of cost. I do not frequent this forum but I can be reached at 604 253 6586. Ian has seen it so it's not a phantom part
Cheyne

Charles@dundonmotorsports

I can vouch for Cheyne. He is legit and has the only good shop in BC that I know of. Someone should buy it out and try it out. Can never have too much data.

fbirch

It would be great to see you develop a complete upgrade kit for the 996 GT3. At some point all of us will need to refresh our engines, and a well developed upgrade kit - backed by quantified dyno testing - would be a great option to have.

Charles@dundonmotorsports

I am doing a budget oriented 996 GT3 4.0 build right now, but this will be basically how low cost can we get to 500hp and keep 100% reliability and such and not have to rev the **** out of the engine.

I also have a bolt on setup for engines that are solid that guys dont want to tear apart, thats the one i'm hoping to get close to 390whp from 355whp stock long block.

The 996-3 4.0 simple build should be done end of april

996FLT6

Wow^- keep us updated : ). Mike

fbirch

Sounds very interesting!

Steve W

The error on a Dynapack comes from and depends upon the accuracy of the operator calibrating the engine rpm to the hub speed. Typically on setup, the operator puts the car in the test gear (3rd or 4th) and revs the engine to what he eyeballs as approximately 3000 rpm on the dash tach, and enters that as the hub speed to rpm ratio. Obviously the accuracy or lack of is dependent upon how accurate the dash tach is and how accurate the operator eyeballs where he thinks 3000 rpm is. Typically I see errors by this method being 2-300 rpm off of the actual value. If you were 200 rpm low the first time the car was dyno'd, and 200 rpm high the second time, you'd have a 400 rpm delta, shifting the hp and torque curves off of each other noticeably. The most accurate way is an inductive clamp such as a Dynojet uses that reads the spark pulse off one of the plug leads, but a Dynapack doesn't have this option as far as I know. So to get the most accurate calibration for such a situation, we connect a PIWIS to the OBD port and read the actual RPM values off the screen which is used to calibrate the to the dyno.

Cheyne

Thanks for the kind words Charles, there are a couple guys around here that know a thing or 2 though.

Cheyne

Actually, If you know your gear ratios Dynapacks are dead accurate on rpm, in fact 100% which cannot be said about an inductive clamp.

Ian, the car did better because the tune was marginal to begin with. The modifications you have done took advantage of the previous map issues, you made a video of the piwis 2 which showed the timing retard of which was fairly steady at zero, there was a little retard occurring when it went on cam. We hadn't spent anytime anylizing what was happening due to the fact that there was not any point In doing such we had no way to fine tune the car. POINTLESS!! Much like the banter In this thread . What I will tell you is the minute you dump those heat soaking cats I will bet you a steak dinner that the ignition retard that we did have will almost disappear. Then fine tuning from that point will be the way to go if you want to afford to do it. Once the basic modifications are done , the $-hp cost start rising exponentially.

Steve W

Perhaps, but in 15 years of dyno tuning hundreds of 911s, and thousands upon thousands of dyno runs done on virtually every dyno that exists out there, I've never seen anyone calibrate a Dynapack by gear ratios, and my bet is it wasn't done in the way in this thread either as that's what's really being discussed here. It is frustrating when the calibration is 200 rpm off, and you are fine tuning map points in software that are in 100-200 point increments as you don't know if you're actually nailing the correct points until you do repeated tests and figure out you're not.

Not sure how you conclude an inductive clamp to be inaccurate. It's a digital count, with pulses per second being counted by a computer, so no eyeballing there. Inductive clamp readings I've found are accurate on a Dynojet, unless the wires of the car have so much RFI leakage, then the clamp and computer can't even get a reading, which doesn't count. It is binary - it either reads or it doesn't and in the thousands of runs I've performed on them, it has been dead accurate.

Rhonda@FVD

Ian,

Nice results with the addition of the IPD and throttle body. Not bad for an OTS tune from many years ago adjusting to your new mod. Did the previous owner deliver the car with the FVD tuning cable or hand held FVD Software Delivery tool by chance?

By the way you are in excellent hands with Cheyne.

Also, a quick hello to Charles.

Rhonda

Rovman

Agreed!!!

christallon

Hi Cheyne. I'll take the plenum and throttle body. Cheers

swbatte

Joining this thread late, but here's my dyno run for comparison.
4 wheel dyno in a controlled room where fans blow air over the car at the speed at which it's travelling, and exhaust fans venting it to avoid supercharging the room.