924Board.org

[Topls82]

Guys
Read all past info re modifications …..has there been a successful
Conclusion or anyone with updated info.
I am in process of gathering parts listed re turbo and cooling from 951
Thanks for assistance
Frank

[Cedric]

Do you mean the water cooled bearing housing on the turbo?
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1980 924 Turbo
www.instagram.com/garagecedric/

[Topls82]

Yes that was a component of the hybrid build along with K27 compressor wheel & K27 housing…
Also was the use of 951 cooling components pump + relay etc

[Cedric]

[Beartooth]

I've just got a stock turbo, but I think I'm on the same page as Cedric on this one: water cooling might be more trouble than it's worth to retrofit. It became standard equipment on most factory turbos because of the lower quality of motor oil and owners who failed to consider cool-down - so turbos would coke up and fail. The solution was water cooling; it probably eliminated most turbo replacements under warranty, but the failure rate isn't much higher with proper cool-down habits. The 931 is worse off because of routing the oil supply line so close to the exhaust, so I wrapped mine in high-temp insulating tape and put a heat reflective sleeve over that. That might be overkill, and it doesn't mean cool-down is a non-issue, but it's got to do some good.

Anyway, if you're determined, it's definitely possible. You'd want to match as best you can where the 951 pulls water from and discharges it to. I'd wonder if there's a way to connect at two points such that you're getting a pressure differential and ensuring flow, eliminating the need for a pump, but I wouldn't break from the pattern of the 951's circuit unless I knew exactly what I was doing. I think it's been done, but I can't point to who's done it. It sounds like you've been searching, so you probably know as much as I do; just seems like the kind of thing people talk about, but most don't end up doing. Doesn't mean it's not worth it, just when things are hard and not absolutely necessary, most people don't...
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1980 931 diamond in the rough

[peterld]

I'm one of those who started the process but never completed it.
My Toofah was primarily a race car from the early 1990s until a couple of years ago. The car has been returned to road specs and softened considerably.
Some 15 or so years ago I purchased the 951 intermediate section and coupled it to to existing hotside and huge coldside. I also puchased a 951 coolant recovery bottle (with extra water outlet) and 951 water fittings.
However the coldside is so big it almost touches the inner frame rail and just doesn't easily allow for water fittings to be accommodated. No joy after having special fittings made, so the idea was shelved, and has never been revisited as the setup as it exists works well with no major heat soak issues.
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80/81 932/8 ROW

[Topls82]

Ideola had post back in 2008 on this ..
But guess if no-one has actual done this I am having 2nd thoughts .
So maybe I can get some feedback on a different approach
Want to get my 81 924 Turbo closer to 200hp
So can I get there with the following
- head work & larger valves
- VW type oversize pistons
- more aggressive cam
- boost control

Any recommendations on these upgrades or others ?
And vendors ?
Thanks for assistance
Frank

[morghen]

To get close to your target you need a front mounted intercooler and upp the boost to 1bar.
You dont need those other things you mentioned, they are great to have but you can get your 200 simpler, cheaper and doing easier/less work.

Wouldnt you prefer to install some tubes, a couple of brackets for the ic and a boost controller compared to doing headwork(read as guesswork) and a complete engine rebuild?

Ideally you would also install an EFI kit from me as well
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Supercharger and EFI kits
https://www.the924.com

[Topls82]

Some details of front mounted inter cooler
Assume air , who provides this and plumbing details
Thanks
Frank

[morghen]

There isnt a bolt on solution, you have to make your own or find a shop to do it. You can ask some guys here how they did it. One of the best setups belongs to Cedric.

If i had kept my 931 i’d also replicate his setup.
I can only provide more info on the efi kit i make for the 931.
_________________
Supercharger and EFI kits
https://www.the924.com

[Beartooth]

Based on what peterld said, it sounds like the 951 center section is more problematic than I thought, although not impossible. It seems it'd take engine out and some work on the inner fender to create enough clearance. I hadn't even thought about clearance issues earlier - that pushes it further into the "things I wouldn't bother with" category.

Anyway, some head work, a cam, and turning up the boost to euro spec levels would get you over 200 HP easily. Probably no need to do anything to the bottom end if you've got good leakdown numbers. That said, it's definitely not the cheapest way to go about it. I'd consider more boost and an intercooler or water/methanol injection. I'd thought about water/meth initially, but quickly found I'm in need of a rebuild, so I'm going to start that first and make up my mind as I go. The nice thing with water/methanol on mild boost is you don't need to pump that much of it to keep detonation at bay, so a gallon or so will probably last several tanks of gas in typical street driving. That said, I'd bet 200 is attainable with a bit more boost, some tuning, and some octane booster. Euro spec is 177 (as I recall), so we're talking about 1-2 extra PSI over that (which I think is manageable here, depending on the gas you have available - I wouldn't push it with California gas, or the like, though).

On the intercooler, I'd say if you're just looking for a bit more power, it might be more touble than it's worth. It definitely takes some investment. ideola's top-mount water intercooler would be ideal for the power levels you're talking about, but you'd have to get lucky to find one. To my mind, if you're having to do it from scratch, air-to-air is the way to go - either duplicate the GTS setup (which has its limits and drawbacks, but a few advantages), or front-mount if you're going for more power or don't want the hood scoop. I've kind of decided there isn't any obvious answer for an intercooler on these - just several ways to do it, and which is "best" is driven mostly by your expectations, budget, and skills or determination when it comes to fabrication work.
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1980 931 diamond in the rough

[Cedric]

The 951 compressor is much much smaller in physical size than the 931 one, and should be good for 300hp. And it can be rotated in any direction, which was needed for my FMIC install.

Raising boost much above the euro boost level is risky, the knock limit isnt far away. Though i think with the larger US s1 compressor 200hp should be doable with head work and cam. Before IC mine did 168hp at the hubs, which could be around 185hp. Euro s2 engine at s1 boost 0.7bar and the largest 931 compressor 2664. The IC takes a lot of work and fiddling but do make the power much more safely and a whole load of power all through the rev range since it can way more timing aswell.

I do need to make my stealthy intercooler write up, its been in the pipeline for a while;)
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1980 924 Turbo
www.instagram.com/garagecedric/

[morghen]