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Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Fri Jun 18, 2021 9:06 am
by Gary71
Bruce M wrote:1 bar of boost = hp * 2
Roughly. Not a kit though, you’d need to engineer it yourself. Turbos have never been cheaper, if you use a common unit like the K03. No need to crack open the engine. Just saying

Yup. You are already in Sport Libre class so why not go for big power and a fat torque curve via boost rather than power via revs?
To avoid the gear changes you may have to change the final drive, but with all that area under the curve the result would probably still be faster even with slightly longer gearing
Also boost

Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Fri Jun 18, 2021 1:46 pm
by 911hillclimber
I went through a bit of 'external turbo' on my Impreza, 370 bhp on the stock 2 litre engine, 7800 and a great gearbox.
Lot of sense to fit one and kill a lot of birds with one big stone.
Water and intercooler rads are a space issue esp getting air to them, less weight attractive, soundtrack odd ,even with the right manifolds
Have a good gearbox in the garage (!) but getting an engine is harder than you think, and will be well knacker'd by now.
The 'box will not fit in the rear of the chassis (tried it) without some hard reworking, and the position of the drive shafts is far from ideal.
Also would need to convert the 4x4 box to 2WD.
Not of that is easy/quick/cheap!
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Fri Jun 18, 2021 8:06 pm
by Bruce M
You’ve got the engine already in there. “Just” needs a few extra bits added.
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Fri Jun 18, 2021 10:07 pm
by 911hillclimber
Asif!
When Bob Watson first saw the car for it's first rolling road session he said
"just needs a small turbo on each side, and there's lots of room too!"
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Fri Jun 18, 2021 11:16 pm
by Bruce M
Example: 2 x r56 Mini Cooper S turbos, EFI plenum & throttle body (stock, cut to fit around fan if necessary), 044 fuel pump, Malpassi EFI regulator, generic injectors, ECU, intercooler over the big fan, oil feed & drain lines, pipe/hoses/hardwear.
Nice little winter project

Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Sat Jun 19, 2021 9:38 pm
by 911hillclimber
That would be busy!
turbo's add a lot I many ways, and goes away from the car's simplicity and period feel that I like so much.
As I felt at Prescott today, it is the uncertainty of the gear change that hinders esp where you need to change gear quite a lot like at Prescott, about 10 gear changes.
loose 0.5 sec on each and your time can be lost.
I can't improve on the 915 box, it's as good as it gets (Bainbridge special hill climb box), and the lack of a defined gate at the short lever adds a lot of uncertainty when trying to change quickly.
A wrong slot a few years ago as I changed from 2nd @ 6000rpm to 3rd, but it went into first saw the engine break expensively mid season.
Took a lot to get it straight in time.
As the start of this thread, if I could have this engine simply rev to 7500 or 8 I could do Prescott in 2nd gear so only one change from 1st to 2nd at the start.
That would be 8 gear shifts saved, about 3 to 4 secs!
Bit of the Lola and Prescott here:
https://youtu.be/pdam6glIkao?t=2679
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Jun 22, 2021 11:31 am
by Nine One One
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Jun 22, 2021 1:02 pm
by 911hillclimber
Saw Ian's For Sale the other day, but no; will be sticking with the carbs.
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 4:19 pm
by 911hillclimber
About ready to pull the trigger on:
Wossner pistons @ 10.5:1 in stock in Germany
Pauter rods and bolts, good for 8K rpm. There are 3 levels of rods!
Cams...still a bit confused but prob Dougherty DC60, but like the sound of an S grind. Time for thinking and asking. Dougherty has been very helpful.
There are some details I'm not quite sure about, ie cross drilling the crank and twin sparks.
WEVO internal kit to be bought, fitted by Mike Bainbridge.
About £5K in that lot.
Californian companies a dream to deal with.
3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 5:39 pm
by Gary71
I’d twin plug it whilst it’s apart. Got to be worth it for the ability to tune the ignition and make the most of the fuel going down the pipes!
Definitely budget for some form of 3D mapped ignition, otherwise I fear you’d not be getting the best out of the higher compression and cams.
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 5:54 pm
by 911hillclimber
Understand Gary, I'll have MB drill the heads for the plugs while all is apart and I take the box up to the Lakes.
It is very easy to get on a real roller coaster with this lot and have to keep a sensible budget and 'bang-for-the-buck' sanity check.
Adding twin spark and ECU systems is another 3K.
Very easy to get cold feet and simply add ARP bolts to the stock rods and 964 cams, single plug, stock pistons and stick to the carbs and ignition. Possibly 7100 rpm max using a bosch rotor arm.
About £2K + WEVO @ £1.5k
With a guess, the final bill for a sharper engine will be £10K, and at that it is hard to feel a good return for the £ considering the place of the car and driver in the scheme of things.
I find it very hard to feel it is justified, just as I did 5 years ago!
I've won my Class in the Midland Championship in the car this year and not for the first time, by simply turning up and doing my best, not bhp.

Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 7:01 pm
by Gary71
Canem ignition only ECU is £500
https://www.lloydspecialistdevelopments ... ition-ecu/
Obviously you’ve got some roller time required for mapping, but you are going to need to do some of that anyway.
In addition you’ll need coil packs and leads, but I’m not seeing £3k.
Think James (Hot66) has canem on his car so there’s some experience to be had there.
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 7:16 pm
by 911hillclimber
I came from an Emerald Ecuador, or Clewitt for the kit to run twin plug maybe later on.
One thing is that the rotor arms for the old distributors go to 7.1 k or 6800 then 6500 which I have at present.
Thought of you this afternoon when you did a spread sheet of parts and prices and suppliers as you started on your engine build some years ago.
I need to do the same detail tomorrow morning.
Wife seems to think I should do it, but may change her mind after the sheet is added up....
Another aspect is the cars coming into the class now, all north of 500 BHP and 4x4 so 40 BHP won't do much!
Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 7:32 pm
by Gary71
911hillclimber wrote:I came from an Emerald Ecuador, or Clewitt for the kit to run twin plug maybe later on.
One thing is that the rotor arms for the old distributors go to 7.1 k or 6800 then 6500 which I have at present.
Thought of you this afternoon when you did a spread sheet of parts and prices and suppliers as you started on your engine build some years ago.
I need to do the same detail tomorrow morning.
Wife seems to think I should do it, but may change her mind after the sheet is added up....
Another aspect is the cars coming into the class now, all north of 500 BHP and 4x4 so 40 BHP won't do much!
You can’t take it with you.
And life is too short to keep a few K in the bank earning no interest.
Do it once. Do it right.
And I’ll come to Loton and listen to the scream

Re: 3.2 911 engine: mods to give 7600 min red line?
Posted: Tue Sep 14, 2021 11:15 pm
by hot66
I have Clewett twin plug coil pack / crank trigger based set up