FBIII

anxious to see what kind of hp you make with short intake runners. I don't think anyone has tried it before!

xschop

Ebay Turbo for reliable 500whp?
If anything like the 951, you'll be limited by the headgasket and/or rod bearings...or the block itself.

Ketchmi

Now that's impressive! Totally out of the box ideas. I can't wait to see how this one turns out. We currently have a 3.0 2 valve that turns 540rwhp and 550 tq and that's on a mild tune. Do the math, the potential is there.

G8RB8

Is that really a good place for a literally red hot turbo? I don't think so, but good luck.

Imo000

Awesome! Always nice to see a home built project. As others said, those weld are good. Way nicer welds than my home made supercharger bracket. Going to let the top of the manifolds stick out of the hood?

Fabio421

By Salamander I'm assuming you mean some kind of kerosene shop heater. Depending on how clean/dirty it burns, holding the plenum in front of it might contaminate your base metal. Cleanliness is so important when working with aluminum. You might want to switch your shielding gas to Helium. Helium makes your arc hotter than when using argon due to it's higher thermal conductivity. Pure Helium is more expensive and it can cause your arc to go funk if you aren't used to working with it. A 50/50 argon/helium mix might be the best for you.

Interesting project. I look forward to seeing more of it.

entropy_engineering

Wow I have some catching up to do. First, I plan on running low boost for a while. That is a cheap ebay turbo. I've made big power on one before. In my experience they have inconsistent quality control. A genuine garrett rebuild kit with 360 thrust washer and a good balance job they hold up just fine. When I get higher in boost I plan on running a comp. The interest to me is the pressure ratio from exhaust to intake. These old design (super T70) turbos have real efficient compressors and it won't have crap for back pressure. What they lack is the ability to spool super fast from using the lightest and smallest parts. They way I see it, my car drove great without boost it's going to only get better. Some 4 cylinder cars like I'm used to working on are boost dependent because they can't hardly leave an uphill drive through without a turbo to help. If I make too much boost too fast I'll just break the driveline or spin wheels. I'm not sweating transient response because I found it easier to very scientifically floor the pedal a half second sooner when I want to go lol.

I'll have downpipe information shortly. Basically it routs down behind the passenger side cylinder head, with the screamer pipe for the wastegate next to it. There's more space than you probably think. The top part of the headers and downpipe will be ceramic coated inside and out. I'm also running dei gold heat barrier on the firewall, back of the intake, and hood. I've had a high mounted turbo on a vr4 setup and the ceramic make it no problem whatsoever. You can damn near lay your hand on it at idle. That being said, I will be running a temperature probe for a while taped to the firewall behind the fuse box.

entropy_engineering

Oh, the intakes fit under the hood with about 2" to spare. I even designed where they clear the factory cross brace...unless the throttle linkage interferes. The only issue with the hood is the compressor outlet. That's another reason for a cheap turbo to cannibalize until I decide on something better.

entropy_engineering

Thanks. I did mean a forced air heater. I wiped it down one last time right before welding. I also shut the heat off to weld so it doesn't blow around my argon. I may get another pure helium tank at some point to mix with the argon. I've welded with it before and you're right it's great. This one is 100% argon because it's also for the stainless (including a "T" for back purging).

hacker-pschorr

I'd like to know the measurment of these runners, Todd's are pretty short:

http://www.erik27.com/todd/turbo/index.htm

https://rennlist.com/forums/928-foru...deo-added.html

He purposely kept his runners short to reduce low end torque knowing the turbo's would make plenty.
In that dyno chart he reduced the power with the tune to lower the torque in the low to mid range area.

The 16V heads make good torque on their own, IMO going with a short runner like this is perfect.

928's have already proven 600+rwhp with stock head gaskets and rod bearings is possible (see above for close to 1,000rwhp with stock bearings and Cometic head gasket).
The 16V and 32V share these components.

The area that is "weaker" with the 16V's has been the pistons ring lands, but I have no doubt this is simply from bad tuning induced detonation.

What is considered a "reliable" power number for 944's these days? 350-400rwhp? If that's the case, then really only two or three 928's have ever surpassed this amount of power per cylinder.
Time will tell.

If and when Todd takes apart the current engine, it will be interesting to see if he is suffering similar issues to high power 951's like cylinders moving around.

entropy_engineering

I figured a few people would ask this one. I've had a couple draw through carburetor turbo systems before. Despite the shortcomings with response I was always shocked by the fuel economy and atomization. I feel injectors too close to the port don't have sufficient time to atomize well before entering the motor at higher air speeds. Looking at motorcycle technology is always one a few good places to look for technology. Most of the newer sport bikes now are running dual injector setups with a conventional injector at the port for cold start emissions, idle, etc. and another shower injector (some with as many as 12 holes!) located further upstream for higher loads.

I was cramped for space and really wanted to keep the plenum volume up. Then I stumbled across this: http://global.yamaha-motor.com/about...df/44gr03e.pdf

From what I can tell, based on that and my experience, giving the fuel something to bounce off of upstream should actually mix it pretty well. You might already guess I'm not too concerned about my cold start emissions. My car has 315's on the back anyway. It's not going anywhere in cold weather. As far as cold starting the motor goes and dealing with the effect on transient response, ms3 has an xtau compensation factor that is adjustable.

WallyP

I would have thought that there might be more room for throttle bodies and tubing behind the engine.

entropy_engineering

Hacker I totally agree with your comments. I've built many different high performance and/or turbo cars in my past and have found poor tuning at the root of most failures. People are somewhat routinely making 500hp to the wheels from 4g63 engines now with rod bolts, head bolts, and a head gasket. I'm trying to be realistic and keep my goals low, but I think my setup can easily eclipse 500 to the wheels on an inertia dyno. In fact, I think I can pass 450rwhp on the U.S. motor with the U.S. cams. Again, I'm not banking on that yet. The turbo is good for about 750 at the crank...but I won't take it near that far.

whatudrivin

I was broken in with working on my eclipse/talon cars. I've seen some crazy set ups and some people running turbos close to the size you are using. Cars that will slide sideways at 70mph due to traction issues with all 4 wheels spinning. That is a crazy sight.

Anyways back to the topic on hand. Any idea how far from completion you are at this point? Also going to do anything with regards to hood vents to help get some heat out of the engine bay?

entropy_engineering

I'm not sure if or how I will vent the hood. I may copy bensen and widen my fenders out. If so I will blend it in more probably since it's a street car. If I widen the fenders I may attempt to vent the rear of the engine bay into the fender area. I still need to finish the headers, downpipe, and wastegate pipe, fuel lines, wiring, mount the intercooler, etc. I would estimate running in the summer possibly.

If you're already laughing at this point, wait until you see the intercooler size and how it's getting mounted. It's either going to look like, "Look! Jethro mounted that there intercooler" or "Don't F$#@ with me". I'm hoping for the latter.