Chris White

You are asking for two things that are diametrically opposed.

You want significant power output at higher rpm (that’s where you are going to get the 350rwhp) and you want power at low rpm and quick spool up. You can’t have both, you have to make a compromise and decide where you want your power band. In round numbers you can get a 3K rpm bandwidth (with some roll off at either end). Do you want 2.5k to 5.5k or 3.5k to 6.5k? your choice and then pick a turbo to suit.

The difference between old designs and more modern designs in that the modern designs are more efficient in their respective ranges. None of them (Old or new) work well when outside of the designed performance range.

Its like asking for one athlete to be good at 100m and a marathon. Not going to happen since the physical requirements of each event are very different.

Interestingly enough you will notice that the 100m and the marathon athletes keep getting faster in their respective events as a result of 'design refinements' due to scientific study. Same is true for turbo design.

Pauerman

Give Garrett a call directly and ask about my statement. I'm sure they will concur with what I've said. Ask them how a journal bearing cartridge handles thrust and how it differs from a BB unit. Did I say that journal based turbos are faulty? What I'm implying is that back to back, the Garrett BB design is advertised as being a more robust platform compared to the thrust and journal bearing design while offering superior spool and transitional boost performance. Is that clear enough for you?

porschefig

Wait, so a k26/6 is the only turbo that can give me 1+ bar before 2800 rpm and hold ~16 psi to redline?? My k26/6 gives me 1+ bar before 2800 rpms (not yet datalogged) and I'm told that if everything is working properly a k26/6 can hold ~16 psi to redline

....6500-(x=<2800)=3700+ rpms of 1+ bar boost (in 4th gear)...

I think Transaxle is looking for a turbo that can do this w/o running out of efficiency at ~13 psi like the k26/6 SEEMS (to me) to do. He's asking for 350 at the flywheel...NOT at the wheels!!!

(just using this example as a point of reference) The Lindsey Racing 340 rwhp kit shows 340 rwhp at 18 psi boost.... is there NO TURBO that can make 1 bar before 3000 rpms and hold 18 psi to redline??????

IF so......I think I need to consider selling my car...

Rogue_Ant

I have datalogged my K27DR to produce 15psi @ 3000 rpm, and will hold 18psi to redline.. (and this is at 5000' elevation, it would spool quicker at sea-level).


Rogue

porschefig

PS: threads have been started that show turbos making 1bar before 3000 rpms and holding ~18psi to redline...so I'm not selling my car ;-)

I was just trying to make the point that the right turbo for Transaxle does exist, and hoping my provoking would get some more suggestions out of people.

porschefig

Rogue beat me to it!!
I'm also at ~5000 feet (no longer in Great Falls)

PS: search for keywords: pauer garrett
username: nize
(I can't remember how to link to other threads)
PSS: I'm still waiting for Nize, and his friend's, dyno results w/ great anticipation!!!!

JE_951

A 27/6 should allow him to get those kind of characteristics for faily cheap if you piece it. IF you wanted to go more exotic then a GT28r may be a decent choice (but thats a guess)

Then agian He is asking for a turbo that can product 350flywheel hp. Well thats about 303rwhp so a 26/8 with supporting mods can produce that. MAF, Tial, 3.0fpr, exhaust will yeild those results.

JE_951

Nize (peter) had a tranny blow up on him right after the initital tuning. I dont want to ruin a suprise that he may have in show for us but I think in th 1psi range he was at 320rwhp with the original intake box and stock downpipe/test pipe, running the Wolf 3d system.

I too am waiting for a ride in his car when finished since I am in the market for a new turbo. I will however say that in the middle of his tuning process I get a ride in the car and it had GREAT spool up. Very smooth but also sudden for great exits.

Peter: if you read this my motor is practicly finsihed so I will be out with you guys shortly!

JE_951

sorry! 16psi range (not 1psi) haha

pole position

Calling the manufacturer to get a unbiased opinion is like trying to get a straight answer from a politician, they will tell you whatever you want to hear.

Garrett makes some great and some not so great products . But they are not the only game when it comes to state of the art technology. Example : Garrett was unable /unwilling to produce a reliaible VGT for gasoline applications but Porsche /KKK did.

Chris White

Um…nope.
You actually said that a ball bearing turbo has less parts. This is incorrect. Maybe I am being nit picky here – but that’s just the way I am when incorrect info is posted as the truth.
“Garrett BB design is advertised….”….OK, so that’s an advertisement….and I should call them and ask them how good their turbos are? I am sure that if I call each manufacturer I will find that their stuff is absoltuly the best…..
Garret makes a fine turbo. So does KKK. If you (in my opinion) want the most durable center section go with a journal bearing from KKK. If you want a faster responding turbo (all else being the same) go with ball bearing (just avoid some of the early units or the cheap stuff – it will fail).
You mentioned a back to back comparison – its pretty tough to beat the long term reliability of the KKK center section – they usually last well over 100k miles for street use and have decades of endurance racing behind them. Very reliable. Maybe not the best in ultimate performance, but very reliable – and that’s what I was addressing in my post.
Have a nice day

944CS

transaxle, you will have to have headwork done to produce those power levels at 16psi.

Rogue_Ant

A GT28RS would be about a perfect solution for 350hp / quick spool, IMO.


Rogue

sawood12

I understand that, however i'd have thought that over 20yrs+ of turbo development i'd have expected the window of efficiency to have widened a bit - introduction of new technologies, new mateirals, more advanced impeller profiles due to the advancement in Computational Fluid Dynamics etc.

Anyway I doubt my budget will stretch to any of the fancy top spec turbo's so I have been considering one of the two: the Vitesse 'quick spool' turbo or one of the Lindsey Super Series with ball bearings (not sure which size). Has anyone got a back to back comparison of these two turbos? They seem to be quite popular so i'm assuming both are pretty good.

Thom

I like very much my K26/8 with Guru chips and SciVison MAF. I hardly see how one could improve the balance between lag and performance by replacing the turbo while keeping the relative laggy character of an old-school turbocharged motor that makes these aging cars so much fun to drive.
At the speeds one can carry on derestricted Autobahns in Germany lag should rarely be seen when traffic is light enough.
IMHO.