Tailpipe Turbo - How can this work? (Pix)

[RarlyL8]

I ran across this while bench racing an old hotrod buddy.

The concept of a remote turbo located in the rear muffler area of a front engine car goes against everything I have ever read concerning turbo theory and maximised efficiency.

How can this work as good as they say? No turbo lag ??????

See details at www.ststurbo.com Click on the short testimonial video.

[dweymer]

They are probably using very small dia. pipe from the header to the turbo to keep velocity high. Total system volume would be large though, so definate boost delay. Do they claim "maximum efficiency"?

[tctnd]

Well, there's plenty of good clean intake air under the back of that truck.

[Oh Haha]

I saw the install of one of these on a newer Camaro. I think it was on "Two Guys Garage"on TV. The concept is interesting and I think it showed pretty serious gains.
The only issue would be where to mount the turbo. If you mount it in the engine compartment, you might as well just put a Porsche turbo on it.

[RarlyL8]

I don't beleive there are any efficiency claims. My headscratcher is the claim of no turbo lag. If this is true you can throw out the turbo theory books and all the money spent on shorty header systems.

This system looks to me as a phenominal home run in the bolt on horsepower game. V8 powered vehicles have tremendous torque to start with. Removing all the under hood fitment hastles is huge plus. Big bang for the buck.

I do have my doubts about their claim of increased fuel mileage though.....

[s2per]

The only time I think that you'd see a gain is when the truck is in a loaded condition, either an in-vehicle load or towing. More available power means it just doesn't have to work as hard.

Towing my 911 and trailer last year with an 8.1 Chevy (345 hp, lots o' torque) "dropped" the mpg from 11 to 10. It hardly knew the trailer was there. This year with my Tundra (245hp, 315 tq), it drops from 16 to 12. Yeah, but at 30k miles annually and only 1500 or so with a trailer, I think you understand my math.

[slow&rusty]

With turbo technology that has come as far as it has, lag is greatly reduced these days with modern high efficiency turbos, here are the concerns with the STS Kit:
1) Presure drop die to increased pipe lengths and bends
2) Very long oil (and water lines) to cool the turbo and drain back
3) Possible damage to turbo underneath the vehicle.

Otherwise a very neat and innovative kit and awesome if underhood packaging is too tight from the factory.

Yasin

[Formerly Steve Wilkinson]

The P-47 Thunderbolt had a turbocharger about the size and shape of an old Bendix washing machine, and it was mounted in the tailcone of the airplane. About 25 feet of exahust ducting ran under the cockpit and back to the turbo, and another 25 feet ran back up to the intake manifold. The P-47's tailpipe was in fact back under the tailcone.

Of course, that was an engine (Pratt & Whitney R2800) running under steady-state power conditions, so "turbo lag" would have been irrelevant, though you did have to wait for the boost to come up at the beginning of a takeoff roll, as I remember...

Stephan

[onewhippedpuppy]

I have seen this on TV too, very cool concept. Whatever show I watched claimed substantial gains as well. As far as no lag, I can't see how. The only turbos that I have seen have variable geometry on their vanes, computer controlled to allow them to spool faster. Other than the pressure drop, mounting the turbo back there would also allow it to run cooler, it wouldn't soak up any of the engine heat, helping the engine run cooler too. The long oil lines would also help dissapate heat, similar to adding finned oil lines to a 911, and I would think that the long run back to the intake might help to eliminate an intercooler.

[tsuter]

Maybe when an open wastegate dump tube gets mounted on that flange you could even use it to grade bumps in the road.

[wholberg]

They could eliminate "perceived" turbo lag by running a turbo that is spun up all the time, creating boost at, or slightly above, idle. The drawbacks to this would be that the intake is pressurized all the time so gas mileage suffers, and above relatively low rpm the wastegate would be open all the time. The benefit is that the turbo lag would be there, but if there is some boost at idle, the car would still seem significantly more powerful than stock at all rpms.

Of course, this would be a less than ideal solution to turbo lag, and I would worry about the longevity of the system. The comment made earlier about the length of oil lines is also a real problem.

Of course, the bottom line is that this will not work on an air-cooled P-car, but it is interesting, none the less.

[ChrisBennet]

Any chance that the long plumbing acts like a compressed air reservoir of sorts? You know, a little like a garage air compressor that has pressure even when the pump isn't running.
-Chris

[RarlyL8]

I don't think these turbos are water cooled. That would complicate installation. There is a big plus in cooling with this location but, as I understand it, a turbo needs to be hot for effeciency. Folks wrap their headers and turbos with heat blankets. These folks claim a cool turbo is a good thing !
I guess the bottom line is that a big high compression V8 on 5lb of boost will hide a lot of lag. How about the 3.2L Carrera Turbo conversions? They have similar compression and boost numbers. Can you detect boost onset or is it hidden as well?

[rbcsaver]

They just installed one on the Trucks TV program on Spike TV. Showed 100 hp gain. It has a separate oil pump as I recall.
regards,
Steve

[Mark McClure]

Lets take the idea and turn it around............a front mounted turbo for the Pcar. Long headers running to the front of the car......cold air intake and a long feed back to the intake. Oil from front cooler.

We could then route the exhaust up and over the roof............like a truck!

Marvelous a new concept is born! Maybe this birth needs to be slapped an put back in again!

[iamchappy]

Mines hanging way back there and seems to work just fine.

[Emission]

Originally posted by Formerly Steve Wilkinson
The P-47 Thunderbolt had a turbocharger about the size and shape of an old Bendix washing machine, and it was mounted in the tailcone of the airplane. About 25 feet of exahust ducting ran under the cockpit and back to the turbo, and another 25 feet ran back up to the intake manifold. The P-47's tailpipe was in fact back under the tailcone.

Of course, that was an engine (Pratt & Whitney R2800) running under steady-state power conditions, so "turbo lag" would have been irrelevant, though you did have to wait for the boost to come up at the beginning of a takeoff roll, as I remember...

Stephan

Amazing... and it got me searching...

From this site: http://rwebs.net/avhistory/history/p-47.htm

"The exhaust driven turbine is approximately 22 ft aft of the propeller and is supported by a ring attached to the lower longerons. The exhaust gases are collected by two rings, one each for the left and right bank of cylinders and directed to the nozzle box of the turbine through shrouded exhaust piping along either side of the airplane beneath the fuselage. Spent gas escapes through a stainless steel flight hood which extends below the fuselage."

[FrayAdjacent911]

What was it in the Mustang that was aft of the cockpit? It was some type of radiator arrangement, but was supposed to add to performance and speed... ?