slownrusty

Interesting thread and good replies....but (there is always a "but")

You guys are putting way too much logic into your replies though...calculating this, calculating that, upgrading this, upgrading that...so time to stop and think for a moment.

I have turbocharged a few NA engines over the years. Some for fun, some for boredom, some for plain stupidy, some for "the doubting Thomas' \ Naysayers out there".....Last victim in my hands was an old leaky engine with 165,000 miles on, ran 15psi of boost in it for 3years, had fun like you would not believe. Eventually leaned it out the motor one evening racing a brand new 400+whp Mitsu Evo.

So...this is my thought, after doing this kind of crazy shananigans for years.

Do an engine health check..i.e leak down and compression. Looks good, looks consistant across all 6? If yes.... then turbocharge away. These flat sixes are great, solid, strong and bullet proof, lots of miles do not mean a thing on them, we get caught up in low mileage this, low mileage that, full rebuild at 80K etc..blah..blah..slippery slope..yadda yadda....be smart when you decide, its fairly easy to determine your engine's condition.

If the doctor gives a good clean bill of health then be a pioneer!:
Buy the turbo headers...cheap...
Buy a good used "modern" turbo and external wastegate...pretty cheap.
Buy a good intercooler and piping...not too expensive.
Buy a boost sensitive fuel pressure regulator...pretty cheap too..
Buy only two gauges...boost and a damn good wideband or AFR..

Do it at home, save a $hit load of money and you learn a thing or two along the way..education is definitely worth it, busted kuncles also worth it.

Set the boost low..I mean "safe"..what I call the boost trickle...4-5psi low controlled by the Wastegate. Do a gentle third gear pull and see what the AFR's are doing...if its running lean time to back off the boost or timing, if not then you can play with carefully shimming the wastegate and adding some more boost...don't get greedy with the boost, cause when she bites..she will bite..and will bring even Samson to his knees in anguish and tears.

The bonus with a higher compression larger displacement turbo engine, is off boost it will have great throttle response...I love that.

I'm all for it...if I lived closer to you I would be egging you on daily.

Forced induction is an addiction, that makes crack look like M&Ms and Gummy Bears.

Shiny Side Up - Yasin

38D

Ok, that I can agree with

RaveDisc

slownrusty,

I am not sure I understood this :
"The bonus with a higher compression larger displacement turbo engine, is off boost it will have great throttle response...I love that."

Do you mean that there's no need to change the compression of the engine (ie. the pistons) if the boost is lower ?

How much horsepower can I expect by turbocharging the C4 ?

Geoffrey

Turbocharging a 964 is straightforward. You can take the stock pistons and machine them down to reduce the compression to 8-9:1 depending on desired boost level. From there you can install a set of turbo headers, a turbo, intercooler and plumbing. If you target a 8.5:1 compression and .7-.8bar, you'll get decent power and a pretty cool car. The trans would be my only concern.

slownrusty

That is exactly what I am saying. Keep the compression stock, keep the boost low, on other words "manageable" and MAKE sure you watch for detonation and the temperature of your exhaust gas...hence the gauges...this is your security blanket. Power will be an easy 100 more than your stock 964 and the torque is what will get you addicted.

Yasin

psiegel

I am running 1 bar with 8.5:1 compression. But I am running this with a large intercooler. Without the intercooler you would need to run at lower boost levels. I don't know what the boost level could be without lowering the compression. That would be interesting to know.

Peter

etom

Here is a low milage 92 turbo for sale, for sake of comparison (looks in great shape--opinions?):

http://cgi.ebay.com/ebaymotors/Porsc...ht_9542wt_1102

slownrusty

$65K...gulp! Says is a genuine S2 Turbo though...

Colin 90 C2

that's because it has the ultra rare "3.0L L4 FI Turbo" engine.