924Board.org

[dreamgts]

Hi guys Im new here and need some advice for upgrading my 924 for a turbo installation. I am also adding a GTS body kit to it. My main concern regards adding a turbo and intercooler to the exisiting factory fitted engine which is a 2 litre euro engine with 125bhp.

I know some of you guys here have made the conversion so any advice on this would be much appreciated. The model is a 1979 having a k jetronic fuel injection system. CR is 9:3 and I believe that it has to go lower than 9:0 for the turbo. i am looking for 200bhp+ without doing any major work to the block or cylinder head but any recomendations here would also be appreciated. I would not like to hear someone telling me to do an engine swap since I insist on retaining as much as the original engine as possible especially the block.

Thanks in advance
dreamgtr
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2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]

With proper engine management and thermal management, there's no reason for you to lower compression ratio. However, if you decide that you want to do it, an excellent alternative for you is to use the Cometic MLS head gaskets, and to order one in the specific thickness you would need to achieve the desired CR. You would need one of the 5-layer gaskets to achieve the thickness you need. You should definitely use the ARP head studs if you're going to forced induction. (Sorry in advance for the shameless plugs. Commercial over )

Regarding turbo installations on an NA, if you look in the Performance Upgrades thread on Forced Induction, you will see a bunch of cross references to related topics here. If it were me, and I was intent on turbocharging an NA, I would copy the approach that DutchPug took with his.

However, if it were me, turbocharging would not be my first choice. With the platform you're starting with and your performance goals, I think going with a centrifugal supercharger would be MUCH easier to engineer because you won't have any concerns regarding the exhaust. All you'll have to do is move the CIS components (fairly easy to move them to the 931 location) and source a 931 alternator bracket for hanging the supercharger. This approach puts the supercharger in an ideal location for a front mount intercooler, which you could add as a secondary stage. The rest of the work is fairly routine plumbing.
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erstwhile owner of just about every 924 variant ever made

[dreamgts]

MMM, very good advice, I will look into the info you recomend. Yet I am not familiar with superchargers especially the one you recomended. is there some kind of data on this forum or elsewwhere where I can have a look into. Also would it be possible to boost/increase the power if i wanted to with the supercharger.
I must add that the car would be used only for race and therefore I have removed loads of unwanted items from the car and also from the engine bay which includes also the pop up motor assembly complete with head lamps, the widscreen washer container also takes some space and this is to be removed as well. Is it also true that for every 100lbs removed an icrease in some way of 10bhp is developed?
Many thanks
dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]

Yes, the weight savings formula is generally believed to be 1 BHP per 10 pounds removed.

Regarding the superchargers, I'm not aware of anyone installing a centrifugal style on a normally aspirated 924 2.0L motor, but there are good examples of roots or whipple style installations...a little further up in that Forced Induction link I gave you above, there are cross references to several examples (simsport, leadfoot, RC, endwrench are the ones that immediately spring to mind).

Vortech and ProCharger are probably the best-known "brands" of centrifugal superchargers. I would encourage you to stay with well known brands, as in the past, there were some attempts here to develop homemade centrifugal superchargers, and every one I am aware of ended up having bearing failure after a short period of time. If you get serious about this route, I have a good friend who is a distributor for Vortech (he has a package for the V6 Mustang that produces 345 BHP), so we could tap into his knowledge to help with proper sizing and possibly with sourcing a unit.

Regarding boost increases, on a supercharger, this is most commonly achieved using different drive pulleys. It's important that the max RPM you achieve with a specific pulley combination doesn't exceed the tolerance of the bearings in the supercharger. With a centrifugal style, you could use a wastegate configuration to control boost, or you could start with a larger pulley to provide small boost increase, and then size down the pulley to increase RPM for increase in boost.

I almost forgot, there is one other alternative that you should consider, and that is a rear-mounted turbo by STS. This is another path that would require minimal customization to the exhaust system. I'm not aware of anyone putting one of these on a 924, but it is an innovative approach, and apparently, with proper sizing of the turbo, there is negligible lag. The added benefit, according to STS, is that the turbo operates at much lower temps in the back of the car, the induction plumbing to the front of the car acts as a natural intercooler, and you don't introduce additional heat gain under the hood. This would be a very interesting approach...if I had unlimited times and funds, I would definitely investigate this path further! But too many projects, not enough time or money to do everything
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erstwhile owner of just about every 924 variant ever made

[dreamgts]

Once again cool info. Im getting interested in the supercharger installation but have to talk to my engine man about itm to me it sounds more easy to fit. i dont like the STS system since it seems very complicated regarding piping etc.

So if I undersatnd you correctly I can leave CR at 9:3.1, relocate the standard fuel distribution system and the supercharger fitted in its position. A smaller pulley will also increase power right? I have seen and read something about detonation, how can this be avoided? Is the solution to this fitting better fuel injectors? Does increasing the CR increase power also? I liked RC's installation of a supercharger very much yet the fact that he just got out app. 160/170bhp out of it isnt much. I think I got up to 150bhp just by removing 250lbs in weight (I wieghed every item gees those seats and motors are heavy)

Finding this forum very interesting hope to hear comments from other members especially about supercharging

Thanks
dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[Scorpio]

[dreamgts]

Hi, my goals, well I have a 1979 Porsche 924 which has been sitting in my garage for about 12 years or so. I have always wanted to do something with it or to it yet because of my work I simply couldnt find the time. Im also into suv's which I have 4 besides other cars.

Plain simple since the 924 is becoming a classis I didnt want it to just sit there and I came across some sites which interested me. these regarded the 924 Carrera GTS type. So I started researching the model well and decided to base my car on this model . The vehicle will only be used for race events, one event is a classic car race which is held once annually (pity really) The race is called GRand Prix De Malte or Valletta Grand Prix, google it for some nice video footage.
Going back to the Carrera GTS model I intend to add the wide panel parts to the car. I have already stripped the vehicle internally and removed some other items such as rear windcreen wiper wiper and front head lamp assembly complete with motor and headlamps. I am working on this department yet I dont want to canabilise the car.

Engine wise at this point I would wish to add a turbo unit to the car and an intercooler (I was considering a supercharger instaed but changed my mind)plus maybe some other mods yet I am looking into theses since i am finding some very helpul information on this forum. I would like to aim for 200BHP+ if possible increasing it by time(most probably I wont be around). My only problem though is that I wish to retain as much as possible of the original engine as possible.

Guys Im 49 years old and have a health problem which might only give me limited time to see this thru. So please dont make any remarks which might offend to my project which is keeping me well occupied and focused on life. I would though appreciate any help when the time comes to start the plumbing work as Im sure it will be available to me by other members.

At the moment Im trying to figure out from which to start in the engine bay, I had a small problem with the distibutor plunger which is now rectified ( gees those things stick like hell when not in use) and changed some wiring here and there. I did revolve the engine and it seems sounds healthy so keeping my fingers crossed tomorrow I will try to start MAX up, I still need to fit the electric pump though which I though was at fault not so difficult to do though.

So guys any ideas or recomendations would be much appreciated, hopefully my little dream of my little car will come true.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]

What are the rules in the race circuit you intend to run in? That will dictate a lot of what you might be able to do.

As for fitting a turbo, DutchPug's approach is the most elegant, and most like the classic GTR setup. If you do a search on Raceboy, he's also done a turbo conversion on an NA. Both of their approaches will require fabricating an exhaust manifold, which will be your biggest obstacle to overcome. Re: your PM, I don't have any more info regarding DutchPug's setup other than what's posted here, so your best bet is to try tracking him down via PM.

The other alternative would be to try to find a BAE manifold. These are rare and hard to come by, but if you can find one, they have a standard T4 flange, which can easily be adapted to a modern turbo. Here's a thread on the now-defunct historic aftermarket turbo kits: http://www.924board.org/viewtopic.php?t=29561
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erstwhile owner of just about every 924 variant ever made

[dreamgts]

Hi ideola. First of all the last pack of info you aimed me to , hits my nail right dead centre on the head, just what I was looking for. As for that race I mentioned. There are many classes in which to compete, as far as I know by info gathered Max would be running in the modified production class since its being ligtened, with the installation of the turbo Max will be competing agaisnt vehicles with cc of between 2100cc and 3000cc . The vehicles could also be of an older vintage year too . In 2007 we had a Ford GT 40 , a Porsche 910 and a corvette which seem to have competed in Le mans during their time. Google 'Grand Prix De Malte' and look for fooatge named Clash of the titans.

Once againThanks for that info , now I have a very good idea on how to start, I think I might have a friend who can manufacture or convert the standard exhaust of Max to something similar to the BAE exhaust unit which looks fantastic. I think that the turbo will fit nicely in that position since I have removed the headlamp motor.assembly and the windscreen washer reservoir ( have you ever noticed how big in size this thing is?) from the front right side of the engine compartment,

Once again thanks and may I wish all members a happy wonderful prosperous new year.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[dreamgts]

[ideola]

Roger's intercooler is an air-to-air intercooler, not a liquid-to-air charge cooler like what I think you're envisioning...
_________________
erstwhile owner of just about every 924 variant ever made

[dreamgts]

[Min]

[dreamgts]

Word of praise to all of you, Im totally surpised and very happy with the feedback and directions. I wish I had something to offer back.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]