14 replies to this topic

[Kartman01]

I am hopeful we can get an informative thread going regarding an short lived experiment in the late 90's/early 00's called the SST - single side turbo.

 

I seem to remember this was a Toyota engine and was only run on ovals.  One side of the V8 engine bank fed the turbo, the other side was open to

the atmosphere.  I remember hearing the car for the first time and thinking it has a cracked header!  Suffice to say the sound of the engine was unique.

 

Does anyone else remember these engines?  I beleive they only ran for one or two races then disappeared.  

 

Hopefully there are some articles or photos floating around that can add some context to this topic.

 

 

[Ross Stonefeld]

There's some info in this thread Penske's Indy 500 engine from 1994 and other mentally fast CART engines - The Nostalgia Forum - The Autosport Forums

 

Photo here 

 

CART Twin Ring Motegi 2000, Large Format, Juan Montoya, round exhaust for pole (speedcenter.com)

(despite URL, actually a photo of Vasser's car)

Edited by Ross Stonefeld, 12 January 2021 - 02:38.

[gruntguru]

Certainly an interesting concept - you could characterise it as four turbocharged cylinders and four supercharged.

 

To fully exploit this, you would need different everything on the open-exhaust bank. Different runner length, valve sizes, valve timing etc. Probably even different CR.

[Fat Boy]

I don't know where all they ran this ear-splitting POS, but I can assure you that it was run in Vancouver in 2000. Atlantics were paddocked under a freeway overpass concrete canyon and those bloody screaming things were insufferable.

[gruntguru]

Can anyone link some video?

[Fat Boy]

Can anyone link some video?

It's unlikely to do it justice. Beyond being very loud, it had a nails-on-the-chalkboard quality that will not translate.

[Kelpiecross]

 What would the advantages be of a odd arrangement like the SST? 

[desmo]

Trying to creatively circumvent engine regulations surely?

[Ross Stonefeld]

I posted the original thread which no one bothered to read? 

 

Short version seems to be:

 

Fewer pumping losses/more power 

Turbo lag increase(less of a problem on an oval) 

Sound 

[PayasYouRace]

I read it Ross.

 

You have to wade through a lot of stuff about the Mercedes 500i but the info is there. Rather interesting too. Indycar has been uploading all their 2000 races in full to their YouTube channel this year. Might be worth watching some of the relevant ones.

[Ross Stonefeld]

I ran through Motegi yesterday and narrowed in on the Ganassi onboards and pitstops but couldn't get a good sound example.

[Fat Boy]

I posted the original thread which no one bothered to read? 

 

Short version seems to be:

 

Fewer pumping losses/more power 

Turbo lag increase(less of a problem on an oval) 

Sound 

Pretty much this. I don't think the turbo lag was that much of an issue, because those cars only ran ~1/2 bar of boost. They made their power with RPM, not torque. It probably reduced temps under the engine cover, which might have helped intake temps, but that's complete speculation.

[gruntguru]

Trying to think of other possible advantages - heat (energy) loss from exhaust header is an issue for turbo engines. On V engines this gives twin turbos an advantgage. OTOH, a big single is more efficient than small twins. The SST has neither problem. Tiny advantage.

[Magoo]

Yes, the idea was that the regulated boost limit was so low that they could drive the turbine wheel with one bank, freeing up the pumping losses on the other bank. Pretty fine whittling and it didn't prove out. 

[Fat Boy]

Trying to think of other possible advantages - heat (energy) loss from exhaust header is an issue for turbo engines. On V engines this gives twin turbos an advantgage. OTOH, a big single is more efficient than small twins. The SST has neither problem. Tiny advantage.

Twin turbo's might have a theoretical advantage (although I wouldn't want to try to package it), but they weren't legal. Everyone was on a single turbo.