Porsche Enthusiasts Club Forum

btw steve/wes, what are you planning for brake upgrades once your cars are running higher power?

my 924t is running 944 cookie cutter wheels, 5 stud, 15inch. can i get any decent sized brakes under these wheels? i would prefer to keep the small wheels if i go ahead with fitting a 944t engine, as i think it will make for a much more fun car, lower grip thresholds and therefore the car will be on the limit sooner. cheaper tyres, and it keeps the car looking standard (ish)

i offered my azev wheels (17inch) onto the car, but they would certainly require a carrera gt kit to house them, and like i say i would prefer to keep smaller wheels.

my potential plan is to fit a 944t engine into the car around 270-320hp. i doubt the steel calipers will be up to the job! as a pure track car i would run trackday/slick tyres which i think will have plenty of grip coupled with the quaife lsd.

brake are my main concern!

cheers
nick

Its in



New WUR location.



Manifold and turbo all lock wired. Bung fitted to enable EGT temp sensor. Nipple needs welding up and trimming back



All ship shape underneath

I've been running monoblock 4 pot Boxster 2.5/2.7 calipers at the front for years now mounted on aluminium adapter blocks with standard Boxster pads. Then just after that I fitted some refurbished standard calipers at the rear with EBC Green Stuff pads.

This set-up stops the car dead on a 2 pence piece on the road.

For track I'd probably fit some different pads.

The thing is, the Boxster calipers sit beneath 16" Fuchs alloys so no fitment problems. If I remember correctly, when we checked fitment with the original 15" spider webs, wheel spacers were needed at the very least to clear the rim. Probably a 10mm+ spacer on each side.

More progress......

WUR in new location. Wired in but fuel lines now need bending and shortening
All other injector lines in.
All intake plumbing and cabling done, even throttle cable works considering its new location/set up
Alternator will fit on new mount under the TB
Cross member not only relocates the fuel dizzy's new orientation but also doubles as taking coolant from expansion tank to rad.

Wow that's a work of art Steve!

Liking the black expansion tank too - although will you struggle to see coolant level?

Great thread guys. Really enjoying it. With different terminology in different countries, what is the WUR that you guys refer to?
Also, I remember hearing how some people thought the 931 transmission was actually stronger than the 944. I can't see how. Thoughts?

WUR = Warm-up regulator, otherwise referred to as the control pressure regulator.

The G31 Snailshell gearbox is strong but has baulk ring synchros which are prone to wear if a degree of mechanical sympathy is not used.

The synchros struggle with the extra mass and inertia of the transaxle layout.
Driven properly though they're excellent in my opinion, and similar to a 915 911 gearbox.
They're both race-derived boxes, which is why the G31 has the dogleg first gear.

Strength-wise though, I've seen a G31 mated to a 650HP Volvo turbo and suffered no problems at all, even with the massive torque put through it.

Strength comparisons though, I don't know as I've not seen any direct tests.

The other advantages with the 931 box is light weight and the fact that it's positioned forward of the rear axle for better weight distribution, as the weight is 'inside' the axles.

Thanks for that Wes. I know of a guy in the U.S. who is putting together a high hp 951 most specifically for drag racing. With his old motor he already trapped at 127mph and equated that to about 530whp. He's in the process of building a new motor that will exceed the old one and wants to try the 931 trans. When I asked him what benefits he saw in the 931 'box this is his brief answer;

"The main points I can see in its favor are the R&P, spider gear sizes. And the shift fork. Looking at the components, it looks to be 30% stronger. The issue is that you have to change the TT and come up with a mounting solution. I just thought I'd try it before doing something more drastic."

On a personal level, I'm hoping my 968 box will withstand over 600bhp. The main advantage I have is that I don't do standing starts!
I've looked at the Iron block of the 924 and wondered what might be achieved with this. I might have missed it in this thread or elsewhere, but is there anyway of mutating a 16v head onto it?

And finally ..........

its all done, in, tightened, buttoned up and ready to turn the key tomorrow morning



Still need to buy black silicone as the blue stuff just won't do. Also need some more Mikalor hose clamps in the right size. Will also get a custom length throttle cable made in due course. Despite trying to keep all the hoses and cabling tidy it still looks like a birds nest!! Needs work I think. However getting it ready to run tomorrow was the most important task.

Artistic that

WOW!! If looks have anything to do with it, that will be a killer motor Steve. Really like that you painted the engine bay as well. I hate putting a new motor into a dirty old bay. Inspirational job you’ve done. Also very interesting that you’ve gone with Omega pistons. I was looking at using some of these on a 3.5L project some years ago. Be good to follow your progress.

The iron block is immensely strong but there's no bolt-on 16v head solution unfortunately. I've no doubt one could be drawn up and machined but would be very expensive unless you have access to decent CNC machinery. It would be a very involved project.

I'm bored so I may as well reveal the change of direction with my current build.

The current plan is to ditch the cast log manifold and turbo location. I really don't want to go back to all the nightmares of fitment and access and exhaust leaks/cracks etc. I'd like a more accessible system.

So with that I decided to ditch the turbo too and go with a newer Holset HY35.
With dual port external wastegate and electronic boost control, split pulse manifold and a few other tricks I reckon I can get the beast up to full boost by 3500-3600rpm. The compressor is a high flow 7 blade wheel and is good for 500hp+. The turbine housing is 10cm3 so pretty small for a Holset but good enough to flow at least 450hp. The turbo will happily push 38psi+ all day long without injury.

I'm mulling over building a very short intake route now with a monster charge-cooler in the mix. I can situate an air/water unit very close to the turbo and manifold and the cores I'm looking at have tiny pressure loss (less than 0.1psi)meaning the compressor won't have much work to do.

From turbine back will be 3"+. I figure if i don't do this stuff now I never will. In for a penny in for a pound or as the yanks say "go big or go home".

I've been pondering over whether to change the main bolts for some rolled thread engineering studs I have of the same 10.9 rating used with ARP nuts. I don't think it's needed but maybe worth it.

After this I have a little-used Aquamist water injection kit that may allow me to run some serious boost with 98RON fuel...

You forgot this Wes