Which GT3 owners are holding back?

Cars like Pel's tracked SC make more sense $ wise as it's already a war horse. Based on my experience I would not buy a 964 unless it was sorted. I think Steve's new car would have been great but like Paul said, I doubt he's selling.

 

Roll on the 11th. I have just discovered why the engine management system is fat in the low range and only average above 5,500 rpm.

Herman should turn up with 30hp more than the last time he ran. Then I have a tune to do on top of that.....

 

Why's that? Spill!

 

Was great having you out, and giving some of us the only chance we'll ever get to brag about monstering a GT3RS. :-D

Beautiful machine.

 

When I installed the Specialist component system I saw no instructions on two lines that connected to the air box. It turns out one connects to the vacuum reservoir attached to the air filter body. This powers the resonance flap.

Colin Belton has a dyno curve on a race engine. 327hp with flap working and 282 hp without it. That's 47hp. Dan reckons I will get 20hp. I'm looking at another 10hp for the cat bypass.

The big push right now is to start Herman up. I'll fit all new lug nuts ex you!

 

Stuart must be Earl Bamber in disguise to be smoking the GT3 crew at 7/10ths in a 996 GT3?

Steve doesn't sell cars. I suspect it may morph into another project soon?

Last thing you want to own out there Stuart IMO is anything with collector value. You will have so much more fun with something nimble and chuck able. You'll learn plenty too. I think Pel will attest to this strategy (I think we diverted him from a 996 t monster track conversion at some stage!).

John. I expect you to hand us all our air cooled asses with your new 290bhp motor!! I'll bring the 993 on the 11th so you can serve it to me. Might be the excuse I need to get my own engine sorted out properly finally. Will be interesting to see the difference it makes. Obviously more than we could get out of Motec/Link with cams and injectors. Have they launched the 993 kit yet?

 

I gotta get a chip now.
But more seriously, and not likely any time soon, I'd like to look at this sort of system to replace the barn door AFM and liberate some horses. 231bhp plenty for now though.
The world must be moving fast now and instead of labouring with expensive OEM air / fuel / spark systems and parts to keep these old girls running, not least the dollars spent chasing faults, there must be more and more fringe aftermarket control systems that enable the dumb (but robust) mechanical parts to keep on turning, and make more power.

 

Don't be too hard on yourself, whilst I enjoyed the "one time I could overtake an RS" moment on the first session, you'd eroded any opportunity I had by the afternoon. Was great to see an RS being pushed around the track, hope you bring it down again sometime.

Found a nail in one of my rear tyres so went to get it looked at and potentially plugged, only to find 3 more hidden away, and a bit of cord showing on the inside, so definitely time to discard the Super Sports and put on the new Sport Cup 2's. Somewhat glad to have collected the nail as the cord was well hidden, and without the leak I would have thought the tyres good for a few more kms. Hope I was the only one that fell victim to the building site at HD!

 

If we start at 250hp, then the cat bypass should have me at 260hp with the resonance flap working. Recognising this only gets me back to original. I am hoping for an extra 10hp and would be ecstatic to get 20hp, from the tunability, but nothing extraordinary.

BTW: With 280hp Dave would need to be lower than 1,130kg to better me with 231hp. Anyone have torque curves for both motors?

 

My first tuner (Hitek) had no knowledge of the resonance flaps. They work on a "high side/low side" vacuum system. IIRC without a complete circuit they revert to long runners which hurt the mid range torque between 3750-4500 rpm on the 993NVR/964. You may need to check that because its entirely by memory. The exhaust needs to be tuned with the intake. One of the mistakes I made that has never been rectified is the exhaust stage. Its quite technical. To get the best cylinder fill efficiency the intake manifold/intake valves size is critical (for a given cam). To get the best exhaust scavenging the exhaust value/exhaust becomes the critical component. As nice as it is to cumulatively bolt up modification with an expectation of adding power as per their manufacturers estimation my experience is the sum total rarely makes the sum of these parts. All that said my modifications in this area were fruitless with a dual exit X pipe that seems to create a pulse problem with my engine negating any power benefit from the cams. Hopefully with the single exit design you wont have this issue. The biggest benefit I was left with was the throttle response and speed of the revs both of which are very good (helped largely by the MAP sensor and LINK tuning). The work was left unfinished with the intention to return and essentially start over from scratch on the exhaust side (something that has never happened). Im sure you will fair better than I did....

 

Mine always cord on the inside too, at least when they don't die from internal sidewall delamination (pays not to spin in the dry) or chunking first. Reckon cording inside is just the car's way of saying it wants more track time. Right now my rears have perfectly even wear, but that is largely thanks to hammering them properly on Targa Tour.

 

I only know about the 964 intake.

There are two horizontal plenums, one above the other. Below 5,500 rpm the lower plenum is closed. This gives better low rpm power. At 5,500 rpm a solenoid trips (the noise 964 owners should hear on initial start-up where it cycles the valve), releasing the vacuum held in the reservoir to operate the flap valve. This allows air to flow in both plenums. I think this is a forerunner to the varioram where changing the intake length changes the torque/power output. Obviously the 964 is a bit cruder because it's on off.

My issue is that I have no vacuum reservoir hooked up so the flap doesn't move. I'll find some pics I took.

 

Pics showing the various parts

 

http://us6.campaign-archive1.com/?u=...7&e=77a29e09fe

Hampton Downs is a changing.

 

I'm talking about a 996 Cup Car, which circulate in around 1.09, so would be running at about 7/10th's to do 1.13-14's