Hey guys, Im new to this board. Ive been reading here for a while as theres alot of very smart people here. Anyway Ive seen some refferences here about the S91's and wanted to try to get a little more info about them and possibley a comparison between it and the GT55-91 - PT91.5 and a Turbonetics 91mm thumper. planning on running two of them on a 509ci BBC in a 10.5 outlaw car. Im not overly concerned with witch makes the most power, as two 91mm turbos will make plenty of power anyways. But more wanted info about efficiency, spooling qualitys and duribility. Any help would be great.

Thanks Jerid

 

Why so large? Twin GT47-88 would spool faster and be capable of supporting about 2800 hp. Twin 76's are good for about 1800 hp and spool even faster than the 88's.

 

We have been selling alot of Twin S80's to some limited street and Outlaw 10.5 customers running 600+ci engines. They will flow more then enough air for those power levels.

 

How about a comparison of all for a single turbo car? I've been thinking about a LARGE single..

 

The S95 is the way to go. 1700+hp and spool up quick.

 

what would the optimal engine combo be for it?

 

400ci-500ci would be my best guess based on the turbine map. But I don't know how to read them quite well yet. Jose and Jason are the only ones that know how to.

 

that's about what I was thinking as well

 

Hey Guys, Well Steve Petty is helping a friend of mine get his combination sorted out and currently they are running the GT-55's on there old 449 SBF and there new 604BBF, Ive already got a pair of Y2K 88's and I wasnt very impressed with how they performed on my friends 441 ci motor. He went to the GT47-88 and ran much better. Since then we have both gone to bigblocks and are looking in the 91mm range. I was looking at the Turbonetics 91mm compressor map and from what I saw, at 15psi and about 1600-1700hp I should be right in the middle of the best efficiency island. Im thinking by going smaller than an 88mm Ill have to run the turbo faster to make the same power as the bigger turbos. If I am looking at it right. But I wanted to get some info about the S91 compaired to the GT55. The motor im using should make between 750 and 900 hp on motor, depending on the final cam choice.

 

The only problem with the GT55 is the reliablity. They won't live for long under those racing conditions. You might want to try something like a S95 if your going thumper T91. They will outspool the big UTV's by a large amount and make as much or more hp due to the new ETT technology.

 

DR Turbo, sorry it took so long to get bak, DSL went down. Can you give me some more info on the S95, I noticed in another post you had a mustang racer using two of them on a 10.5 O/L car. IS the turbine on the S95 the same size as a Thumper? also, are yall doing those in ball bearing?

 

Dr Turbo, Also what is ETT technology? And how would the S95 compair to the ball bearing Turbonetics 91mm? One more thing, Have you guys heard anything about alot of guys having problems with the Y2K turbos? Anyway Im very interested in the S95, do you have any pictures?

Thanks Jerid

 

The turbine wheel is a tad larger then the GT55, but smaller then a UTV. It flows ALOT of air though compared to the UTV and will outspool them as well.

Also the 10.5 car was running only a single S95 on those test passes, for the regular season though another is being added......so should be VERY interesting. No BB yet, but not really needed since they are using a VERY strong bearing structure.

 

ETT stands for extended tip technology. Which means a 95mm ETT wheel will flow like a 98-100mm standard wheel but not add the mass and lag that would be acompained with a physically larger wheel.

 

The S88 would best be suited for size CI motor? 364-388's?

 

The S88 will work fine with 400ci engines, but at that point I would start thinking 91mm+ unless you have limited space.

 

DrTurbo any update on the S91?

 

Just FYI, look in my sig for power on pump gas...

 

Dr T, what backing plate are you guys using on the S95, is it the steel on like the Garrett's or can you put an aluminum on there to save a little weight?

 

S91's are still prototypes and are in R&D phase right now. They will be testing soon for some #'s.