BigBlue

HOHN, what's your opinion on the schwitzer line of turbos?

Big Blue24

GFB, what clutch did you order OFE or FE?

GFB

OFE 13" conversion kit. rated for 500/1000. I don't want to be breaking any hubs with the small clutch!

Big Blue24

I have the FE... free replacement cause the performance 13" upgraded woven stock facing, one step down from the ofe, started slipping after 2K miles when I traded out my edge comp for an edge juice. This is why I believe that the Juice has newer.. better fueling down low than the original comps came with.

HOHN

Keep in mind this is JUST MY OPINION.. Not fact by any means.

The Schwitzer line of turbos is great-- but not a true performance setup either. They are designed to last forever-- very durable shafts and wheels.

That's why I say they are not true performance turbos. Nothing at the leading edge of performance is designed to last forever. Rather, performance parts are designed to be as strong as they need to be-- for as long as they need to be-- and no more.

For example, a NASCAR engine isn't built to run 1200miles. It's built to qualify and run up to 600 miles. Heck, it's even tuned to the track with a shorter distance getting a more aggressive tune!

Racing engineers talk about revs/hr rate. Literally, the figure out how many times the engine is going to have to spin over the course of a race and make the parts as weak as they dare and still have them be as strong as they need to be.

How does this apply to turbos? Well, a "performance" turbo would have quite fragile wheels that are VERY light. The shaft would be a little lighter too, but the shaft doesn't contribute that much to rotational inertia, so there's no much point in weakening it to a severe degree.


A "performance" turbo would be able to handle 2000+ EGTs, but not tolerate barking. It would be designed to last multiple passes or pulls at the track, but certainly NOT be designed to last 200K miles over the road.

People have talked about how a certain t-netics turbo may have been known to blow. Well, yes. These are not OEM turbos designed to last the life of the engine. They are racing turbos-- mostly fitted to race cars making 1/4 mile passes. Hence, they get a lot of maintenance and that is considered "normal" for their usage. This usage is MUCH different than an OEM spec situation where the turbo would have to last a long long time under much less load.

If you had a faster spooling turbo on a race truck, you wouldn't have to launch at 20psi and destroy trannies and axles. Instead, you could launch at lower psi and still get the holeshot you needed. Right now, spoolup matters little because CTD racing is almost like a trans brake class. But with lighter, more fragile "performance" turbos, you could tailor the truck to take advantage of the more manageable power delivery, and be faster overall.

Now, for those of us with street trucks, durability is CRUCIAL-- we hope for as much performance as we can get, but we won't accept shorter life to get it.

But in racing, short lifespan is not only tolerated-- it's welcomed in many ways. Because if you overbuild your engine or car in the name of durability, you'll probably lose to the lighter guy who built his to be "just enough."

My opinion on the Schwitzers, then, is that they deliver amazing performance for a street/oem style turbo that has to be "over built". But for harcore dragracing, you could do better--- in theory anyhow.

Again, just my amateur OPINION. I have little to no experience with these turbos, so take this free post as being worth what you paid for it.


Justin

Mike Holmen

Hohn, I've thought about doing what you suggested. Build a twin garrett using the ball bearing shafts. Everyone has talk me out of it. Honestly how much better would they over mine? Marginally, yes. I do think that the HP will be higher? Slightly. The only beneift is that your gonna have a flatter torque curve, that starts at a lower RPM's as the boost will be there faster. How much money is that worth? I think a supercharger and turbo set-up will fix allot of smoke and spool-up issues of the big sticks. Then run a big turbo like a 62/14 on top of a 8-71 blower set-up to run tons of air (overdriven to the max). I was told that a diesel wouldn't idle with a 10psi boost load on it from a super. You would have a set-up to push 1200-1600 cfm of air to 80-100 psi boost. Instant spool-up of boost as you have 5-10psi of boost at idle. No smoke. Tons of power. Less money than the Garrett route.

HOHN

Hence, why everyone is really doing it. The marginal performance increase is more than offset by the much higher cost and reduced reliability.

But at the ragged edge in a high-dollar race operation, it would be done.

We're not at the point where turbos are limiting diesel truck performance. It's tranny and traction tech that's limiting it. We have enough power to push these trucks to low low 10s at a light race weight, but doing that through our current transmission tech is tough.

Ideally, we'd have a sequential clutch setup kinda like the Fuel classes use.