I read a couple short articles about the VW Golf GT (not GTI) that is going into production for the European market were they employ a supercharger for low RPM and turbo for higher RPM. The tiny 1.4 liter motor will make 170bhp and 177 lb/ft of torque. I read in one of the articles it will get high 30's for fuel mileage.

http://www.autoweek.com/news.cms?newsId=103408

 

Here is another article about it

http://www.gizmag.com/go/4595/

Now back to the topic

 

Seems like there is an electronically controlled bypass for the supercharger at high rpm, which eliminates the turbulence issue I mentioned.

Nifty!

 

Yeah, and a clutch, kind of like what the supercharged MBs use when they idle, except this one disengages when the engine reaches a certain speed or at a prescribed boost.

 

pleas epost pics of what the turbo setup was in excellence without the headlight mechanisms.

 

I'll post them tomorrow night, I'm going to bed in a few.

 

thats cool.

 

with 9.5:1 compression and low boost theres no need to put the turbo there...you're gonna be spoolin just off idle with 944 Turbo....i'm all for your conversion but i'd say make it really easy on yourself and model things after the 944 turbo and not the callaway...after reading so much you should know that the callaway design is inferior to the 951's....

 

I disagree. The crossover design sucks. It adds more weight, more potential loss of energy (via heat transfer) from the exhaust charge driving the turbo, not to mention the crossover pipe is a HUGE pain in the *** to work on, causes premature failing of the oil pan gasket and rear seals, etc. Not to mention the loss of rapid response. Everything is a compromise, but given the choice of the 951 layout and the Callaway-style layout, I'd pick the latter every time.

 

Well I don't see any Callaway turbo systems making much power and I would hate to work on one with how much stuff they crame into such a small place. I also can see with all the heat that will be produced in such a small area, pan gasket failure on the one side. It is just dumb to argue about the two considering you don't have a Callaway car to work on, test or to see the problems it could cause. When it is very easy to rip apart the 951 system because it has been around so long and the problems are known.

 

Both designs are pretty old, but I'd probably do something similar to the Calloway design. The crossover of the 951 is rather silly and there are ways of mitigating the heat issues of a turbo on the exhaust side of the engine.

 

he DOES have a callaway

i would pick the callaway design as well.
i think the callaway design was inferior because they prolly didnt have a whole fatory perfecting the system, it was even before the 944 turbo, and the exhaust manifold is pretty bad, and the fuel delivery system is pretty primitive.

thats why im not making my manifold like that. when i thought up the idea I didnt even know callaway cars existed. so I dont think im imitating them.

 

Does he have a real Callaway car, or is he puting a Callaway kit from a Callaway car onto another car? I can't quite tell, not that it really matters either way.

 

I wasn't going to say anything. . .

Mine is the Callaway parts going onto another car - which is great for learning about the system but terrible for being a pain in the butt!

There was some dude in Hemet (kinda' near here) with an original Callaway that was selling it a couple months back. I discussed it with him, but felt his price was too high given the condition of the rest of the car, so I passed. He might still have it - dunno.

Yea, everything's a compromise. The pass-side setup is (again, IMHO) superior due to its simplicity. The "stock" Callaway setup was dynoed at 284 hp at 6,000 RPM so while it doesn't make "dfastest951" power, it's more than adequate - considerably more than a stock 951 or even a 951 turbo S. I fully expect in the neighborhood of 350 RWHP when all is said and done off of what is fundamentally the same system, albeit with a larger turbo (the IHI-6B would never support this), water injection, more advanced intercooling, etc. I've no doubt those numbers are attainable.

The only difference between my setup and a Reeves-built one is that mine will utilize slightly higher compression, 2.8L displacement, moderate head work and alusil bores (R.C. used steel liners as there were no alusil-compatible 8.0:1 c/r pistons available in his day that he could use inexpensively).

Although the Callaway design is 1980s, so is the 951 design. I personally favor it for its simplicity and ease of installation. The setup was so tight, Callaway was actually able to adapt it to a 928 (ever see how tight the 928 engine bay is?). He fit the same exact system, one on each bank (twin IHI-6Bs) under there on FOUR 928s. A guy on this board owns one of them. From what I've been told, it's stooooopid fast.

My point is, both systems are a compromise and work reasonably well. The 951 is a solid design overall, but has its flaws. So does the Callaway design. However, I'd rather work on my Callaway project ANY DAY than a 951 - and I seek to prove that reasonably big numbers are possible from the Callaway setup using only technology that was available in 1985.

 

While the "log" style manifold is somewhat primative, it's not a major problem in a turbo set-up until you start chasing max hp. Certainly there are cheaper and easier ways to chase turbo hp than an equal tube length manifold.

IMHO the fuel delivery and engine management system is the most primative thing and reasonably easily overcome today.