924Board.org

[Joe bar]

My basic plan was to refresh the head , so i would just deliver the head to a shop , and let them refresh it , maybe renew the cigments ( or whatever you call them in english ) and go for a bigger gasket so that i reach a compression ratio of 9:1 , and then i would go for a pressure of 0.6 bars .
There is only 1 thing i dont get with mutch of your replys , you can just mount a turbo of a 924 , that really isn´t the discussion , i have all the parts and just mounting it would be done in 1 weekend .
The real qeustion is , will the engine like it , will i still be able to use it every day without having problems every month , and witch adjustments i schould make to the head and the compression ...

Another qeustion i just thaught of , does the clutch like 180 hp´s or will i be forced to put the T bone gears in with the clutch of a turbo ?

( i hope that anyone can understand this post , i have a big headache of a birthday party yesterday and i really couldn´t put in the effort of spending half an hour on this post to make it a bit readable )

[My924gtc]

If you want to run lower boost like that you will want to be in the 8.8 - 9.0 range for compression. How you do that is up to you but the 2X headgasket is easier than new pistons, and less expensive.

The clutch might have to be upgraded to a Stage II in order to handle the added power but that is nothing more than replacing it. No need to change the system or anything radical. Just a Spec clutch kit will do.

You are going to want to have the head 'fixed' by really modifying the intake port. Do a search on this site and you will find the info on what needs to be done.

And just to clarify something in regard to the opinions you are reading...of the people that have commented only 3 of us have either added power to the 924 NA, or are in the process of doing it. One (leadfoot) actually drives a supercharged EFI car, one (CBass) has a well modified NA, and one (me) is working on a supercharged EFI motor (and the kits for everyone else to do the same). The others are just spewing rhetoric.

You are clear to proceed with making that turbo kit work on your car. Get the compression down, get the head work done, and let her rip. She ain't gonna explode if you keep the boost within reason.
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MJ
'81 924 2.0L T
'82 924 2.3L SC/EFI <---online fall '06

Sponsor of the 944 Cup and Super Cup
Sponsor of the "2006 Battle in the Badlands"

[morghen]

the clutch is my only concern...i dont find the NA clutch strong enought for the NA....i think the turbo would chew the NA clutch very quickly.
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Supercharger and EFI kits
https://www.the924.com

[My924gtc]

[Joe bar]

[My924gtc]

Not going to be street friendly mind you but stage 4 will do what I promised if you have the guts to try...

http://www.horsepowerfreaks.com/price/Porsche/924/SPEC/Clutches-Flywheels/Clutch_Kits

The cost and replacement coupled with the cable actuation is why I prefer to make the 924's into track material rather than the 931.
_________________
MJ
'81 924 2.0L T
'82 924 2.3L SC/EFI <---online fall '06

Sponsor of the 944 Cup and Super Cup
Sponsor of the "2006 Battle in the Badlands"

[CBass]

I wouldn't say my engine is that well modified, the headwork on it is terrible(previous owner)...

Again, the compression is not as important as the management of the fuel and spark. Keep in mind that VW/Audi and Porsche have been running 9.3:1 compression engines with 1 bar and more of boost for the last 18 years in street cars. Granted, they all have much superior combustion chamber design than the 924, which significantly lessens the tendency to detonate, but with a correct fueling and timing especially if there is some form of knock control introduced, you will have no problems 0.5 bar of boost on 9.3:1 compression.

The key is good fuel injection that will provide you with a nicely richer than stoic charge, around 11.5:1, and some careful and conservative ignition tuning. Whether you go with the CIS, stand alone EFI, hell even carbs, there are many ways to do it. I'd recommend standalone EFI such as megasquirt for ease of tuning.
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'81 931 in various states of assembly

[ESC944]

Alright first.. I was thinking... that torques me off another... buy a 931 post... must be an echo or a lot of cattle following the herd….

Everyone who knows me knows I love boost and push it like a drug dealer.... dark alleys and private conversations come to mind... boosting a na is taboo... its bad medicine... dont do it... save your self, run out and sell your 24 and find a 931 yea.

Its like saying dont chew on the tree bark... how could that help you with your pain... no dont do that... how awful... get rid of that stuff... get some Tylenol or Motrin... or for real pain get some Tylenol with Codine... crank up the boost on your 931... yada yada. Sometimes old school is cool and works.

I am so tired of buy a 931 or buy a 951... maybe that works for someone with no skills and no real knowledge... I cant stand to hear it cost to much, its to much trouble... etc... then I see leadfoot made a lot of my points. I would say their are a few poeple on the board that have a real clue about boost. But like he said, no one comes around saying... oh no if you hit even X psi engine will grenade... etc...

Dont think so... now in my posts I might skip over the engine prep side of things... and that is critical, but i assume most people have a clue about that sort of thing and I have posted as much as well.

Bottom line... you can boost anything with an ICE... period! How much boost is relative to a lot of cost....

But come on people... but a 931? Please spare me.... You dont even need EFI or CIS, carbs work and work well... a PIA to tune, but work... How about a nice 4 barrel feeding a turbo in a draw thru configuration?

Hemmm? How about you use a cross over pipe ala 944 styel, mount the turbo with rebuilt and feed it fuel from a 2 or 4 barrel... (4 barrel being over kill) Jet it right, tune a little... done. Is it perfect no... but you can put the CIS stuff in a pile poor some gas on it set it to fire and dance around it praising the joy of being free of that demon spawn. Or deposit in the nearest trash receptacle.

Even if you build a log style manifold ala BAE style or even smaller... worst it would cost you is 150, you can get equal length and all that made for 300-400 (i know I had some made for the 44), a used turbo, plus rebuild about 50 for the turbo and 150 to rebuild. You can rebuild it yourself for even less.

Exhaust pipes and hose 100.00 rebuilt carb 50.0 2 barrel, oil lines etc..

hemm your labor to put it in priceless.. you would pay a lot more for someone to teach you or let you watch.

So thats what 400 max for manifold, less if you go crossover...
200 in the turbo... I have a few I would even donate to a worthy cause.
150 for the rest

So thats 750... hemm toss in a blow off valve for 50.00

800.00 make that around 650-700 to do a cis setup, you shop and you shave, buy quick pay a lot....

So a 1k 924 na or less that runs decent... heck I seen people get more for less car wise...

So an 800 maybe 1k if you toss in extras or a stand alone oil system for turbo....

I could do it for far less, but I got skills... now if you can put toast in a toaster or run a blender, you can install a turbo... hard part is oil lines. Safe yourself the heart ache go stand alone.

Takes time, say a weekend, set it up for max of 5 psi and hold on....

Oh you want EFI not CIS and a turbo.... thats cheap too...

But you have to think out side the box.

Now anyone who thinks it cost as much as a good 931 just to boost a 924 can go get bent.... your wrong. Period.

But a boosted 924 is not a 931, its a faster 24.... now converting to 931 or 944 specs as far as 5 lug and all that... that’s a different argument.

Even if you think I am low balling ok... toss in another 500 cause your to lazy to shop around or get your hands dirty whatever.... wow what’s that 1300... gessh break the bank.... ouch.

Now of course we are not talking new.... but gossh gee wiz you could have bought a rebuilt BAE kit for 1500 or a used one for 600....

Or build your own...

Makes me sick listen to people regurgitate the same drivel, buy a 931... get an original opinion or some real world experience.

IF a NEW turbo kit for a HONDA is around 2.5k you don’t think you can do a 924 for less? CIS is good for one thing... no need to chip it.

What oh detonation... water injection baby toss in some alchy.

Oh extra fuel... please don’t make me laugh. I can build a system out of junk yard parts that no one wants, giveaways and so could u... if you had a clue.

Oh what want the system to handle that for you, sure fuel enrichment system for the 924 of 931... got it covered, especially the 931... but yea that will cost ya.

Don’t say it can’t be done unless you tried and failed along with enough people to make that a realistic appraisal of the situation. Otherwise... its sound like an echo, buy a 931 buy a 931.....

What you want serious power... ok
24 or 31 engine rebuild, good head gasket, apply serious boost. mix well shake often.... poof high performance.

I like the 24... you can get throwaways for cheap... or free... no I wouldn’t say boost a free POS 24, but why not put the same money you would spend on buying a beat 931 on the 24... you end up with a better 24, otherwise, you end up spending money on the 31 getting her up to speed... its always levels of investment.

If 1k for boost is out of your budget... well guess you need to save your pennies.

ok for someone who says it has to cost that much, fine you got 2.5k I will build you a new turbo system from scratch you can bolt on, with all the toys if you are so convinced it has to cost that much... but trust me you will be paying me for my time.

Otherwise you go buy a 931 and leave the rest of alone, spare us, if you havent done it... and/or you have 931 what exactly do you base your advice on? hear say? Yea probably... nothing wrong with the search for more power... thats why this is the performance upgrades section, not the buy a 931 section... or some factory promotion.

Want a bargain basement system, cheap, fine pay me and I will put it together for u… other wise… go out and do it. Don’t listen to the drivel about buy a 931. You already a 924 work with it.

Help the guy, do what he wants, not what you think is the most economical... or atleast say... what your saying is based on a common thought, not original thinking or experience....

Help him boost his car... he want advice on how to do it, not if its the best choice... your posts should read well yea hear is how to build a fire, but if you play with fire you "might" get burned... not "no no dont build a fire, what where you thinking... their is something better... and its safe too"

NO one adds boost to a 924 NA cause the engine isnt the best platform to start with, and most owners dont want to spend the money... but technoligies improve constantly... it gets easier and easier. But the biggest hurdle is the head... for real power.

Don’t think so? Well even if I was full of it… must be something to it, considering all the groups and sites on the web dedicated to home built and home brewed systems… used, new… whatever…. Go for reliability, that doesn’t have to be new or expensive or even store bought.

OH YEA and as for buy a 931... find one first, then try finding one that is in good enough shape that it doesnt need a lot of work and performes like you really want... thats like looking for rocking horse droppings.... good luck.