hacker-pschorr

It only proves that turbo's get hot.

Yea, Audi has no clue what they were doing for 20+ years of making cars with the turbo right next to the head. Even Porsche must have been filled with a room full of morons that put the 944 turbo under the intake manifold. How about the holy grail of turbo cars – the Supra. Ever see where they placed the turbo’s? Guess Toyota has never seen pictures like that either. I guess they could make well over 900hp if they moved the turbo back 10 feet.

Dennis Wilson

Erik,

I've owned three turbocharged cars in the last 20 years and only one (80 Monte Carlo SS) did not have additional factory modifications to allow more air to the turbo. Guess which one wore out the turbo every 20K miles? Yep the Montie and it only ran at 7 psi boost. Putting the turbo in the rear will require some engineering to reduce lag time but it will increase the longivity of the turbo and all the under hood rubber parts.

Dennis

SharkSkin

Right, VERY hot. And sharks get pretty hot under the hood too. Add a couple of red-hot lumps and you have a serious heat management issue. IMHO the point that was being made was, that's a LOT of heat to be putting under the hood of a shark, where there's no effin' room in the first place. Take the turbos out of that Stupe-ra and look at the size hole they needed to stuff them in there. Finding a way to bring all of that together into a shark is definitely not for the casual DIY 928 owner. It would take some real commitment to make a TT shark and make it streetable.

drnick

has anyone got a rear mounted system up and running?

hacker-pschorr

I'm confused - what does a 951 have to allow for more air flow over or to the turbo that a standard 944 doesn't have?

Hey, I'm all for any setup that makes a 928 go faster. The rear mounted turbo just seams like a huge compromise. I’m sure with enough trial and error, you guys will figure it out.

FlyingDog

I didn't know that. Thanks for the info.

I agree with HP, turbos mounted by the engine are better. The only true advantage to rear mounted turbos is ease of adapting non-turbo cars.

Dennis Wilson

Erik,

The 951 grill has extra venting for more air plus oil cooler and the turbo itself is is oil and water cooled.

Dennis

hacker-pschorr

What venting? The only change is up front to push air through the intercooler. What turbo isn't either oil or water cooled? The 951 turbo is buried under the intake manifold. I'm not saying this is ideal, but it works for the 944's.

Dennis Wilson

Erik,

The 951 has extra cowling on the spoilier. Also air is deflected up over the radiator. Also, the 951 turbo is both water AND oil cooled. To put the same cooling on a 928 would require a lot of sheetmetal work and adaption of a 951 K27 or K28 turbo which is made for a smaller volume engine.

Dennis

jyoon

the 951 turbo is under the manifold to keep it farther away from the header and keep it running cooler, they last much longer than say a mitsubishi eclipse turbo which is attached to the manifold approximated 6 inches or so away from the engine. the mitsu turbo glows red when running and still works fine. it needs replaced more often than the 951 turbo, but it's so much easier to do. you could probably do it in 1/4 or less time than it takes to do the 951. imho mounting a turbo in the back seems extremely inefficient.

Imo000

Isn’t every turbo oil lubricated and water cooled? The oil is for the lubrication and the water line is more or less to cool the bearings a bit. I’ve never seen a turbo that only had one and not the other.

tammons

Turbos in the back of the car is an interesting idea, but considering that no factory car has ever been built that way, should be a clue. You are going to end up with way too much lag and you still have to run an oil scavange pump. If you dont mind running a scavange pump, a better place is to mount a T4 low on the passenger side at the back of the engine. There is room there. Basically at the bottom of the engine straight down below the water tank. If you use a water cooled center section, that keeps the heat down and doubles the turbo life.

FlyingDog

Some turbos are oil lubed and cooled. It doesn't seem to be very common anymore.

chris0626

Actually MOST of the [aftermarket] turbo's you can find are oil-cooled only. After a hard run, most folks just idle the car to bring oil temps down (a couple minutes is all it takes). Water cooling will increase the longevity of the turbo bearing... although just exactly how much is anyone's best guess.

All this talk of underhood heat is pretty funny. Unless the car is driven to extremes, heat should NOT be an issue. Headers will get just as hot. You don't think superchargers generate any heat? Come on guys... If the car is moving there IS airflow, otherwise the engine wouldn't run.

FWIW: take for example my MR2... it's mid-engined AND turbocharged... no big front-mounted intercooler. Underhood temps get hot, but if your cooling system is up-to-snuff, not a problem at all. Guys are making over 700rwhp and cooling isn't even a concern.

Tony

[QUOTE=tammons]Turbos in the back of the car is an interesting idea, but considering that no factory car has ever been built that way, should be a clueQUOTE]


There will be one on the Dyno saturday as well as a Twin turbo S4 and other types of HP adders!
Should be a fun day up n the PACNW!