[chrisbalich]

Originally Posted by 1979-930

If you want affordable power you need to build a EFI turbo car. To reproduce turbo power NA is BIG $$$$$.
My Turbo will accelerate as fast as the RS upto about 90. Then that 8K redline in the RS takes over.
But I have about $15k in mods to the 3.3 to get it to do that. If I ditched the CIS and went EFI there is another 100hp hiding in there.
But the 930 has plenty of power as is and I like the fact I got a CIS car to perform this well. There is something cool (to me anyway) about making 40year old mechanical technology perform.

I've spent fortunes making slow cars fast. I'm not after a fast car, but a complete car.

Originally Posted by Mixed76

I would spend as much time getting the gearbox perfect as anything. That, to me, is one area that newer cars really shine and enhance driver engagement.

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This is very high on my list of things to sort out. I'm still formulating a plan, but I've got it roughed out. I haven't talked about it because I still have a long way to go before I can afford to fully build a gear box.

Originally Posted by Garen

Completely get this. Same road map for me in my 930 build. I think the most important variable in capturing the GT3 spirit Is refinement, actually. Not sound-deadening, cold-AC-blowing refinement, but chassis tuning, and a tractable ECU map, plus the all-important gearbox. If you manage to get all the bits to work in harmony, as-in tune the suspension to work best at the ride height and tire type you intend to run, it will start to get closer to the GT3-esque benchmark ("feeling" not outright performance). Without spending massive dollars, it will be impossible to match the GT3. I know you get this, but that's where most go wrong in chasing a benchmark. It's actually harmony. Why else does the ole' OG '73 RS still rank so high in comparo tests? Because it's dialed-in to use all of its abilities at a high performing harmonious level.

You've got that dialed-in feeling just about everywhere in your project, judging by the result, the aesthetic sensitivities, and even the writing style and your approach to documenting the build. It's yours, and it shows. Now you just have to make a couple of key decisions, and realize them to the full potential that your budget and chassis can provide. Get the suspension dialed-in, to a high level of engineering detail, (geometry, bump steer, the most appropriate damping vs torsion bar specs, with great tires). I bet it will start to give back the GT3-style feedback you seek. Then follow up with some WEVO bits for the 915, and fine-tune your ECU tune.

After all, it's nice that Porsche absolutely tried (and succeeded) in capturing the spirit of the old air-cooled performance-variant 911 in every GT3 variant. They just upped the ante a bit (ok, a lot).

Will be watching this, more great stuff to come I'm sure.

Thank you very much. I reckon you've hit the proverbial nail squarely on its head. All the things you've listed/mentioned I'm still working on. I think I need to re-up my level of patience. I've come a bloody long way to get this far, there should be no wonder why I'm not at the finish yet.

Originally Posted by Jonny042

Doesn't the GT3 weigh over 3000lbs? Lets just say 3300 with one human gas, and 409hp..... that's 8lbs hp.

You can have a civilized 911 that weighs 2300, so lets say 2550. You only need 320 or so HP to equal the power to weight ratio of a GT3. Not that is would be quite the same (less torque, more traction, electronic nannies, etc.), but I figure even with 275hp-300hp (easy to achieve reasonably) the excitment level in a truly lightweight car is going to trump the GT3 any day of the week, while also having much lower limits - safer and more fun on the street.

Anyway since you are smitten with the GT3, and havent driven one, I'm guessing the performance isn't the biggest quality you want to emulate. In that case absolutely yes you can capture the spirit of one with your car. And it can be a hot rod at the same time, can't it?

Mixed76 brings up the gearbox thing, too. I put close ratio gears in the Rot Rod (2nd and 3rd) and Project Heavy Metal (2nd, 3rd, 4th). I will tell anyone who will listen, this is absolutely the best thing you can do for your car.......

With my sweet new hood, I should be at (or under) 2250 wet...plus me. Engine development (beyond sorting my calibration) is last on the list. Once the car is done, I'll revisit what power to weight I need to complete the package. I'll 100% be in touch when I get closer to time to build the 915.

Originally Posted by jpnovak

yes, reduce weight and match gears to rpm band in the car. Fun factor and driving dynamics (character) increased X10. Add to it competent suspension and you have your dream 911.

Still working on those lbs. I will be ~2250 (wet, 3/4 tank of fuel) by weekend's end. I can get sub 2200 by changing to FG bumpers...but it'll transform the way the car looks.
I have all new bushings in a box downstairs. Need upper shock mounts (camber plates), balljoints, and shocks and the suspension should be sorted.
I reckon the gearbox may have a larger impact on driving dynamics at this point. It handles decently, but my gearbox is in a bad way.


Thank you, everyone for your input so far. It really helps me to process my thoughts when I have such a great sounding board.