924Board.org

[Euro924S2]

I have big plans - just few ideas!!!!

Introduction for background if you have time to read!!

Hi all. I've been away for a couple of years or so now as I bought a house which has needed a complete referb and with no garage the Porsche was sadly put on bricks in my parents garage. The plan was to get the car back ready for this summer but My brother beat me to it by dropping his Supercharged MX5/Miata (running 200hp at 12psi 1.6L) into me to fit a new standalone ECU to properly map the water injection inaddition to the fuel and spark. The success of this project coupled with driving my girlfriends new Audi TT 2.0L Turbo (again 200Hp) has left me feeling inadequate in my 924 which has a standard Euro spec engine, but with lots and lots of other modifications.

So my thoughts changed to boosting the Prosche to 'keep-up' with the other cars in the fleet!

So my wish list:

1) I want to keep my current 924 but increase it's power, rather than sell and buy something else.

2) I will be using the car on the road for less than 5K miles a year with little or no track use.

3) I would like to do a '1 stop' upgrade, rather than do it bit by bit over the years.

4) I want a 'reliable' upgrade - ie I'd rather change bits for new at the outset, rather than worry they're going to fail as soon as I plonk my foot!

5) I'm a torque searcher rather than a rev demon! Ie Little turbo lag is more important than a screamer - I'm quite happy to change at 6k maxed out providing boost comes in nice and low down.

6) I'm looking to achieve in the region of 200 - 250 BHP.


So to this end I have bought a Euro spec Series 2 Turbo which hasn't been started in 10 years with the thought of pulling the engine, checking and replacing parts as needed, replacing the CIS with Stand alone ECU fuel and spark control and then once all is sorted, swap the engine, box and brakes into my 924 NA.

I am continually searching and reading but thought I'd start a thread I can update as I progress.

Your thoughts please?


(formally Porschenewbe)
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[ideola]

Check out my 931 club sport build thread. I'm doing almost exactly what you describe to that car. Same base starting point, similar final goal.

If you want the boost ASAP, you'll need to keep your S2 turbo. To get more low end torque, you may want to consider increasing the CR a bit, or you can go crazy like I did and try the stroker approach with custom pistons. To lower CR you can either order a thin Cometic head gasket (going from .50 to .26 minimum thickness will yield ~.3 CR points or you can have custom pistons made (figure $650 for four custom slugs, another $160 for coatings if you want them).

The other thing you could do for low end torque without messing a whole lot with the basic power plant would be to setup a twin charge system with a low psi positive displacement supercharger handling boost from idle, then a one-way valve to switch over to the non-linear boost of the turbo. If you did this, you might want to switch to the S1 turbo to let the supercharger handle from idle to 3000 RPM, then let the turbo kick in. You need to make sure you get a positive displacement supercharger for this to work, either a small Eaton (M45 or M62), or the path I had investigated, which is the IMI twin screw setup from a Mazda Millenia.

Regardless of the path you take, you can always increase boost using a boost controller and an intercooler. The Carerra GT had 210 HP with less than 1 bar of boost and a less than ideal top mount intercooler on essentially the same internals as what you currently have. That's a good target to shoot for!
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erstwhile owner of just about every 924 variant ever made

[Euro924S2]

Thanks Dan. To address your suggestions individually. I've read about the twin charger setup on here a while back and I'm not sure its a route I fancy embarking on - as a technical exercise it's a fantastic solution but it's twice the fabrication, and twice the complexity to setup. I would have thought this more suited to running BIG power when a BIG turbo will take an age to spool. (of course I may be wrong however!!!)

As for the stroker option - this is something that possibly appeals, especially if I find significant wear on the bore and on the main bearings - that said if they only need a light polish (unlikely after 116K miles) then it's probably a big expendature for not a massive gain.

One thing that is troubling me is the possibility of a turbo swap. I've done loads of searching and the trouble seems to be the 3 bolt mounting flange which is uncommon to say the least. I've seen several posts asking about possible other 3 bolt turbo units but I can't find any posts to suggest either a) cutting off the 3 hole flange and welding an alternative onto the manifold, or b) welding a 3 hole flange onto analternative turbo or c) making a converter plate (like you can get for different alloy wheel PCD's). I assume there must be a reason otherwise you would all be doing it - so please enlighten me as 'modern' low pressure turbo's (like on my GF's TT boost from 2k revs and seem to keep pace all the way to the redline! I wonder would this not be a better route to pursuit rather than the stroker kit direction?!?!

On a personal note Dan, I looked on your site too - are you selling the fuel rails for EFI and the flexi J-pipes at the minute? (i'm putting together a shopping list!!!!)
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[Rich H]

Hello,

My thoughts: An adapter 3 bolt to 4 bolt should be perfectly possible, no real problem other than access to the bolts should you want to pull the turbo. You might want to check the manifold for cracks though the RHD turbo manifold never got the reinforcement the LHD cars did.

I would say a FMIC is a must, a nice big one. Otherwise I'd leave the rest alone assuming it's all healthy.

With EFI and ign you could esily have a 220-240 bhb car with reliability too and standard compoents so you can easily replace anything should the worst happen.

I have a complete MS1 unit for sale rigged for MSnS + with EDIS unit and coil pack - £150
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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

[Euro924S2]

Hi Rich. Glad you've seen this post, plqanning on putting it onthe owners club as soon as I get a minute to retrieve my password too. As for the MS - I've got a redundant Gotek ECU which should be ideal and half the reason to change to electronic. The other half is the discovery that the flywheel sensor is broken off (althought the electronic DICM looks good and will be up for sale as soon as plans are finalised).

I know you converted to electronic fuel and spark, are you still running this setup or have you changed attack? How was your lag with your FMIC? What RPM were you starting to see boost?

Dan (Ideola) suggested raising the CR to give more off boost performance - problem is higher CR = greater risk of pre-ignition = more cooling needed = bigger FMIC needed = greater throttle volume = more lag!!!! The expression rock and hard place come to mind!!!!!!

I agree though, I'd like to keep internals new origional (where needed to replace worn components) but a modern turbo appeals if it give me a quicker spool with less lag.
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[Rich H]

My MS was on my old N/A

The Turbo is staying on DTIC
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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

[Euro924S2]

I just read your thread in the 'how to folder' - Mondeo fuel rail - I'll be ebay searching when I get home (ebay blocked at work - 924.org not though!!!!!)

Let me know if you need any DTIC spares - I'm gunna have a box full pretty soon!!! Plus WUR etc etc !!!!
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[Rich H]

Mondeo fuel rail will be hard work as it's quite tall. Could probably be cut in half and made into 2 short rails linked with pipes?
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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

[Euro924S2]

Oh Did you not use a Duratec fuel rail?
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[Rich H]

It's not a problem on an N/A on a Turbo you have intake pipes in the way.

The final iteration:


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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

[Euro924S2]

oooh, that would be tight. I've just measured a gap of 8cm from cylinder head to under the intake tube (thats on my series 2 - maybe different on a series 1) Looks like your right and I would guess the mondeo is about 9cm above (judged by looking at height relative to the rocker cover bolts)

For £20 though (loads of Zetec ones on ebay for that, but no duratec ones) it might be worth a look.
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp

[fiat22turbo]

Take the head off and have the stock injector bores machined to fit the injectors lower in the head (also helps get the injector nozzles closer to the air stream)

Shouldn't be too bad to do for a machine shop, I was able to do it in our home machine shop with a cheap mill and a couple of boring bars.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[Rich H]

That head above is machined (Well drilled by hand...) and the injectors are about 1/2" lower than they normally would be.
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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

[fiat22turbo]

Ah, good to know. I think then, it might make sense to look at the size of the fuel rail and see if there is any space that can be gained there.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[Euro924S2]

Been thinking about this and if I use a FMIC (which I definately will be) then I won't be using the stock ally air intake pipe. Infact I'd need a 90degree bend (not ideal) to bring the intake from the Right hand side of the FMIC as the turbo will be feeding from the left so that 90degree bend (where your filter is mounted Rich) should allow enough room to have the fuel rail sticking up a little bit.

So I can get some measurements - what fuel rail did you use exactly - I know it was Ford Duratec (is that the diesel?) but what year and engine capacity???


Cheers fellas.
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UK spec '83 N/A with 931 motor with Eaton MP62 'charger @ 15psi. EFI - 565cc inj. Standalone Adaptronic ECU. 951 FMIC. Ally rad. Twin throttle. Recirc valve. Custom manifolds and CAI. 232bhp