924Board.org

Rich H · Posted: Sun Oct 18, 2009 6:41 am Post subject:

Knew that was coming.... Stand by...
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

Rich H · Posted: Sun Oct 18, 2009 6:47 am Post subject:

First is looking through the core in the direction of the airflow, second is the top view (If you hadn't worked it out!)

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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

TurboBullet · Joined: 08 Feb 2009 Posts: 64 Location: Southern NJ

I started on this a while ago but other projects and life have gotten in the way...I have all the pieces cut and ready to weld for completion!

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87 Porshe 924s custom widebody

Rich H · Posted: Mon Oct 19, 2009 4:56 am Post subject:

Ordered some brass and solid rivets.
Plan is to use the rivets for mechanical strength and the solder the joints for the air seals.

We'll see how I get on...
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

ic932 · Joined: 11 Feb 2005 Posts: 1104 Location: UK

I can only take "strictly bolt-on" to mean that you feel there is some sort of re-sale factor involved, hence the reluctance to cut sheet metal?

I think that this is quite noble, but unless you cop the cost for a genuine CGT IC then you would be better off leaving it stock. If you want to increase the HP then intercool it properly or not at all. I sold a 951IC for £25 the other week so it's peanuts really...

The power level of 177bhp will always be a disapointment in a chassis that Porsche squeezed 350+bhp out of. I find the 211bhp of the 944S2's that I'm playing with at the moment are under powered and in need of some FI. The CGT was only rated at 220bhp with turbo lag...not that impressive really...especially when you drive this chassis at this power level on a day to day...Ask Creenen as a 951 owner.....?

I don't like to be negative but it's as cheap as chips to to it right anyway.. I can't see that you are saving any money whatsoever with this approach and there is no real re-sale value to worry about. In fact, a well done IC job will help re-sale because most potential future 931 buyers will know of the IC's importance not only in terms of extra power but lower charge temps = reliability/longevity.

Btw, I have a new unused 937 wastegate core, and all the parts to re-build it...open to offers.

ic932 · Joined: 11 Feb 2005 Posts: 1104 Location: UK

flosho · Posted: Mon Oct 19, 2009 10:28 am Post subject:

Interesting setup! I looked at those pics a couple days ago, then looked again just now and noticed its an intercooler!

IC932, how would there be any turbo lag on a cgt, with the top mount the lag shouldn't be more than a stock 931. I would expect full boost of <18psi by 4000rpmi max.
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[This Space For Rent]

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

I think he means that it is not an "instant" 220 Hp or whatever, it takes some time for the turbo to spool up. That is commonly referred to as "turbo lag" and is an inherent trait of turbochargers, weather or not the system is intercooled and the volume of any plumbing. Wherever there is a turbo there will be some turbo lag between idle and full power. Not an issue on aircraft, marine or stationary & industrial engines, less on full drag cars or circle racers but a major concern in a street car.

From Wikipedia:
http://en.wikipedia.org/wiki/Turbo_lag#Turbo_Lag

Rich H · Posted: Mon Oct 19, 2009 5:57 pm Post subject:

Yes re-sale is the idea, ther are few enough unmolested 924 Turbos out there as it is. This car is almost totally original, only the wiring has been hacked about (Being rectified slowly) and the paint is a bit of a mess but find me another 932 with no sunroof and manual windows...

As I stated above this is a technical challenge, also no one knows how efficient or otherwise this will be - it might be awesome...

Power isn't the goal either really, my car is 18 bhp down on factory which has a rebuilt turbo and block so is annoying, but the WG hasn't been touched - hence why I have one coming from Dan for rebuild.

Rich
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

peterld · Posted: Mon Oct 19, 2009 10:34 pm Post subject:

Hiya Rich - it is noble to try and keep your 924T in standard/or easily returned to standard condition and I applaud you for it. God knows there are hardly any unmolested ones left. Most of us have cut and changed things over the years, and I'm guessing that some day they will be like 914s are now - short supply of original ones and worth something. Though I wouldn't hold my breath waiting either>

There is plenty of room to mount a FMIC in front of the radiator providing you get your piping right without having to necessarily cut anything.
Andial are the only people to my knowledge who have the wastegate rubbers at around $60 US from memory. However the wastegate springs are available from lots of places in the US. Try Automotion. They are afterall 930 parts. Check ads in Excellence or PW911 for leads.
Make sure you lap in the wastegate valve well (super hardened seat) and you'll almost certainly find the walls on the wastegate scored by the sideways movement of the spring. Just clean up, rebuild and good to go. Helpful to have a big mate push down on assembly (held in vice) while you button up the six studs - you'll see what I mean, particularly with a 1 bar spring.

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80/81 932/8 ROW

Rich H · Posted: Tue Oct 20, 2009 12:20 am Post subject:

Tell you what then I'll measure up and see if I can fit one in. Would be easier in the long run I suppose...

Still going to have a crack at the charge cooler bit anyway, it's going to stand me around £30 all in so not bad. Also seeing as it's ali, brass and copper I could weigh it in as scrap and make some money back...

It's the pipework for the FMIC that I don't get, it's going to be very tight in there and very messy with routing...

Thanks for the WG rebuild tips, I'll watch out for that!
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

tuurbo · Posted: Tue Oct 20, 2009 12:26 am Post subject:

You could also use water/methanol injection and keep the chassis in tact.

The other day I took the 931 out for a run, and the water/methanol injection circuit and pump worked just fine. It's been about 2 years now that I've been running this setup and haven't had a failure yet.

Something to consider, even if you install the IC, because you may want to increase the cooling.

I think your goal is (1) bright, because of the resale issue and reliability under hot conditions issue (2) the most enjoyable and pleasurable option you can choose. It may or may not be 'perfect', but making your own intercooler? How cool is that? Very cool, imho. Gives ya a feeling of pride in your accomplishment. That's where it's at dude.

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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

Rich H · Posted: Tue Oct 20, 2009 1:20 am Post subject:

That's what I thought.

The other thing is that SWMBO is away playing with fast jets so I'm unsupervised for a couple of weeks so I can work in comfort on the sofa in front of the TV...

_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

Rich H · Posted: Thu Oct 22, 2009 9:35 pm Post subject:

OK discovered a couple of things:- blowtorches can be too hot and modern lead free solder is rubbish!

I have 2 blow torches one MAPP and one propane, the MAPP one has piezo ignition so it the blowtorch of choice but it gets too hot too quick for soldering! It basically boils off the flux and chars the surface of the solder...

Propane is better but doesn't like being tilted over too far.

Lead free solder refuses to flow nicely, it just blobs up and falls off. I melted a bit of the original solder and mixed it in and it flows lovely

Need to find some nice (highly toxic) lead filled solder....

Top and bottom plates are now on, looks like it's going to be very tight fit with the bonnet and inner wing, but I'll have to wait for the weekend so I can remove the boost tube and check properly. I will definately need to move the pipework to the back edge of the tanks and blank off the lower ports as the foul the cam cover.

Oh and as most of you probably know, when soldering clean clean adn clean again - it makes things much easier...

Need to make some cardboard templates for the rest of the ducting now.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

tuurbo · Posted: Thu Oct 22, 2009 9:56 pm Post subject:

So the soldering worked? Refresh my memory - what metals are you soldering?

I'm looking for a project now where I can use this stuff:

http://durafix.com/

A tad pricy though.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.