Don't castrate me - turboing a stock 2.5L

[blown 944]

I give up.... is 18 psi not enough proof.... what do I need to run 25,30psi

Not worth it..... give me a break . If you compare the $$ and the fact that most like to play with their current 944's It is definately worth it IMO.


Anyone can just go buy a 951 if they have the $$.... I did ....,but I still like my little '83 it is a ton (well just over) of fun . Definately moreso than the 951 around town.

This is the nicest response I could come up with please keep the conversation going so I can get up to the track all the sooner to show how "never" worth it ,it really is!!!

[blown 944]

After reading about the Subi I am convinced now that more than ever that timing and fuel control and inter-cooling is key. Even with relatively low boost #'s that I am wanting to get to.


Unless you run E85. This eliminates many of these issues.

I would be carefull using everything posted in that thread to determine your outcome. He made many mistakes and honestly he is working with some real junk parts too.

Just so you know, I have ran up to 12 psi on regular pump gas w/o trouble

The IC is really a must I think, Unless you are experienced with methanol.

If your car is a late 924 you should be able to use the upper alternator bolt as an idler pulley location. Just have to get a longer and possibly thinner (using a nut)bolt and a spacer for the pulley bearing.

Even a stock 944 fuel pump is fully capable, currently running 18 psi using stock bosch unit.

The RRFPR is a good tuning tool but I like to have a slightly larger set of injectors so it is not the only mode of fuel adding. I currently know of 2 or more people running (NA at the moment) with much larger than stock injectors at lower fuel pressure than stock,with even good fuel mileage results.

[AaronM]

Originally Posted by Dean924s

People should understand that I am not building a 951. I can go by one of those. I am having fun.

Bingo.

Remember though that a lot (most?) of the questions about putting a turbo on a NA are from people who think that they _can_ build a 951 that way. Those are the kinds of people I try to discourage from these sorts of projects. If they have the idea that they'll just be able to slap a turbo or SC on the car and have it perform like a 951, then they need a quick talking-to.

But if they just plain like tinkering with mechanical bits and enjoy a bit of a challenge, then by all means they should go for it. Cars are not a monetary balance-sheet type of thing, and if the person enjoys working on a project, then it can definitely be worth it to build a forced induction 944.

[blown 944]

Well said ^^

[Dean924s]

Originally Posted by BauDMoN

I have looked at the non-turbo to turbo conversions and found it is NEVER worth it.

Why?
1. Engine upgrades and mounts to handle added compression, hp, torsion, etc.
2. Drivetrain upgrades to clutch, trans-axle, gearing, etc.
3. Suspension upgrades to handle the higher speeds
4. Braking upgrades to slow you down.

Conclusion:
Buy a turbo that is pre-engineered to include all of the above, and enjoy the driving time.

The basic division in this debate is that some like the process of developing there own variant on the forced induction car while others like to drive what Porsche has to offer.

Neither is better. Both options will work for some neither will work for all.

In short. Some like the journey while others prefer the destination.

[blau]

Wow, I let the thread languish for a month and look what I get...Prepare for more Porsche noob questions.

After being super discouraged by initial replies to this thread, I initially decided to keep the car mostly stock, fixing what's broken and daily it until I had enough cash for a 951. However...

I now have possible access to a 928 parts car (A/T, like 90% of the rest of them). How many of the drivetrain parts are swappable without major fabbing? If Porsche is anything like VW, I know there's gotta be lots of platform parts sharing.

Blowing the motor sounds very tempting. It is currently getting mild blowby at startup and decel, I think up in the valve seals or guides, so while fixing that I could put a headspacer in and lower compression a half point or so.

I do enjoy tinkering, and that's what this car was supposed to be from the outset - a project. I don't want to build a 951, I want something unique.

Blown944, how much of your drivetrain is stock?

[blown 944]

All of it at this time.

I do have a turbo trans on the floor for when and if it goes.

[blau]

Wow, 18lbs on stock drivetrain parts?

I get the feeling it's a little more sturdy than I've been led to believe. Do you have any dyno #s?

The Callaway turbo kit posted earlier sounds mildly interesting, but the turbo it comes with probably won't spool until forever...I currently daily drive a VW 1.8t and love the near-instant torque it provides with the itty-bitty stock turbo.

[AaronM]

Originally Posted by blau

Wow, 18lbs on stock drivetrain parts?

I get the feeling it's a little more sturdy than I've been led to believe. Do you have any dyno #s?

The Callaway turbo kit posted earlier sounds mildly interesting, but the turbo it comes with probably won't spool until forever...I currently daily drive a VW 1.8t and love the near-instant torque it provides with the itty-bitty stock turbo.

If you don't drive hard, the stock transaxle is OK. The durability problem comes from fast shifting or just dumping the clutch between shifts. And it's not as though it will break immediately. The process takes time.

18 PSI seems like it cannot be right to me. Even a 951 cannot handle that level reliably without new injectors, a larger FPR, and a re-mapped ECU. Although, if he's only running that high with the alcohol/water injection I suppose it could work....

[blown 944]

That's exactly how I do it

Definately not recommended for the average non alcohol fuel driver(read don't try this at home). I never said it is possible on regular petroleum fuels but ethanol (E85)with a methanol injection system, yes, very possible. It does have it's drawbacks like going through a ton of methanol I don't laim to be any sort of supertuner not really even a tuner I just know my way around blown alcohol stuff a little. http://www.youtube.com/watch?v=BMmX4caf5Us

And don't forget the 951 will need a bigger turbo to sustain those boost #'s at high rpms too. I know, I blew my turbo up trying to match the supercharged boost level

[AaronM]

Originally Posted by blown 944

That's exactly how I do it

Definately not recommended for the average non alcohol fuel driver(read don't try this at home). I never said it is possible on regular petroleum fuels but ethanol (E85)with a methanol injection system, yes, very possible. It does have it's drawbacks like going through a ton of methanol I don't laim to be any sort of supertuner not really even a tuner I just know my way around blown alcohol stuff a little. http://www.youtube.com/watch?v=BMmX4caf5Us

And don't forget the 951 will need a bigger turbo to sustain those boost #'s at high rpms too. I know, I blew my turbo up trying to match the supercharged boost level

I knew there had to be alcohol involved. Wish I had E85 here for the 951. I could really turn up the boost then. As it is, the stock injectors seem max out right around 16 PSI (275 RWHP/300 TQ) with 92 octane pump gas.

A K26-8 can hit about 18 PSI reliably (or so I've been told), but the K26-6 of the earlier cars isn't a great idea past 14-15 PSI. I've heard tales that it's done successfully, but it really heats the incoming air a lot.

[blown 944]

It hats up the air and in my case it bleew the exaust turbine apart trying to get every once of boost out of it (wastegate was hardly opening) .

I was also using methanol on this car to try to cool the overheated air. It did go a 13.70 but the MPH was only 93. It was also 93 at the 1/8th mile so it was on a good run (most likely 115 mph on the big end if it would have held out) when it happened.

[Dean924s]

Sid,

Do you have any photos of the 83 NA car engine compartment. I would like to see how/what you did with the intake etc. Basically I am just gathering info. The more I can get the shorter the learning curve. BTW I have come to really like 2" exhaust pipe!!! It is easy to weld/bend and with a little cleaning and some high temp paint looks rather cool as well. It also matches exactly the diameter of he stock 951 piping to and from the inter cooler. I am building my intake plumbing out of this and so far it has been great!!! And I am just to dam cheep to get a TIG when my MIG just keeps on ticking.

The next challenge that I will be starting soon is routing the intake pipe from the back of the head unit back around by the coolant tank and out in t the fender. I was seriously thinking of using a radiator hose form an old Chevy and putting a spring in it to keep it from collapsing. And then there is the fitment of a K&N cone filer in the fender. Thank god that the local parts store has a very large in stock supply of K&N filters that I can play with.

[Dean924s]

Just to update my project. (I will start a new thread on it as soon as I start taking photos)

A pile of parts have arrived (thanks to eBay). I have budgeted $1000 for the build and so far I am about $350 (I have not added it up in the last couple of weeks). I am wondering if I can do this for less than $500. I will post a parts list with the approx prices I paid. One thing to note is that I have my own MIG welder so I have the ability to fabricate stuff. With out this the price of this project goes up exponentially. The other cost I have not got yet is for the machining/water jetting of the 1/4 in steel plate that will be used to mount the head unit. I am betting that it will be at least $100 just due to the labor to get my cad drawing in to the computer.

I will post my plan later as it seems almost to simple to put an inter cooled supercharged intake system in to these cars.

[blown 944]

Dean,

sorry I mised this earlier.

Here are some photos.

What did you end up getting for a s/c?


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