TonyG

I like the turbo a lot (the Garrett). It's a great turbo. The K27/6 is a very good turbo for a stock engined 2.5 for sure. I would not upgrade from the K27/6 to the Garrett unless I planed some serious engine modifications (which I have and am continuing to do... I'm talking about very expensive custom headers/cross over pipes, billet cams, extensive port work on both the intake and exhaust, short runner/big plenum intakes, etc.... Just bolting on a test pipe,"O" ringed Powerhaus head, MAF, etc.. is still considered a "stock" engine.


On a street engine, you want to get on the boost as soon as possible. That's what makes a quick fun-to-drive car.

My website, <a href="http://www.tonygarcia.org," target="_blank">www.tonygarcia.org,</a> has plenty of dyno sheets of a 2.5L stock engined K27/6 setup. The boost is all in by 3500.

The Garrett by contrast "hits" a "smiggen" over 4000.

The Garrett pulls better past 5500, and makes more power from 5000 up, but no where near 50+HP. More like 25HP (seat of the pants dyno) if that.

But... the Garrett will support extensive engine modifications which is where I'm going (where I'm at), where the K27/6 is pretty much limited to 2.5L stock engine cars with all the bolt on crap. No in this context, we could see much larger power gains. I'm shooting for 425HP to the wheels on a 2.5 at 18 psi boost.


To put it into perspective.... I ran at Willow Springs last weekend.

I was in back of a 2002 Z06 Corvette. 405HP and 3130lbs. And... by the way... these are damn fast cars around the track in stock form!

Coming out of turn 9 I could pass, and did, the Corvette.

In 3 of the run sessions, he started before me. All three runs, I passed him down the straight and I was running 16 psi boost on 100 octane fuel!

Currently, here's the mod list (haven't installed the headers, head, cam, intake yet):


Stock head, stock cam, stock intake, stock throttle body, stock headers. Built bottom end, no balance shafts, aluminum flywheel, lightened knife edged crank. 3" stainless manderel exhaust from the Garrett back into (3) three Borla XR-1 race mufflers (very quiet), RC Engineering Indjectors, ARC2, MAF, bla bla bla

CPTdooberhead

I've got a ball bearing T04E as well. I have hit 28 PSI. Believe me. Theres a reason im changing out my headgasket!

Mike B

[quote]Coming out of turn 9 I could pass, and did, the Corvette.

In 3 of the run sessions, he started before me. All three runs, I passed him down the straight and I was running 16 psi boost on 100 octane fuel!<hr></blockquote>

Music to my ears... <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" /> <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

TurboTime

TonyG, let me know next time you race at Willow Springs, I'd like to come out to watch. I live just down the street. I'd like to see your setup, talk shop, and see you smoke some Z06s

TurboTime

GaryK

I think the 46 trim is a good match for a mostly stock engine like mine. I don't get 12psi by 3200rpm like Russ does, but the problem is altitude which kills spool-up here. But the lag is no worse than the K27/6 and I'm sure it will flow efficiently at 16psi to redline, with much less heat and backpressure.

And thanks for your encouragement during my install, Russ. As you know, the turbo is bolt-in but not a direct fit. This is the largest compressor that will "fit" with the stock intake manifold. I had to grind down the heads of the throttle return bracket screws, remove the front bracket for the manifold altogether and cut off the mounting boss, etc.

Also, the alternator prevents a straight shot from the MAF to the compressor inlet.
And the temp sensor water pipe that was on my car for the K27 wouldn't clear the new compressor. Jason at TEC was kind enough to modify it for me.

Gary

Pat Kennedy

OK so, can we empirically compare a K27/6 and a T04E? Can anyone post compressor maps or hard data comparing the two?

This has been a very interesting thread, due to my currently failing K27/6 (bought it used from David Lindsey) and I'm trying to decide between having the K27/6 rebuilt or springing for something else. Problem is, my funds are earmarked for a GURU stage 2 MAP w/bigger injectors, some SFR exhaust and maybe an AVC-R.

I currently have a 2.8L stroker, stage 4 MAF, DeltaGate and MBC.

I've never had a turbocharger rebuilt before, what's a ballpark dollar figure for this service? My local Porsche tech tells me there's a local place (Milwaukee) he sends them to and it is the same place Windward sends their turbos for refurbishing. Now personally, I run from anything Windward as fast as possible, but that's due to their own lousy customer service. But this local turbo refurbisher is KKK certified, and if they do Windwards turbos, they probably know what they're doing.

Luke

I would be interested in the seeing the difference in the to4 "B" and "E" maps.

tazman

[quote]Originally posted by Luke:
<strong>I would be interested in the seeing the difference in the to4 "B" and "E" maps.</strong><hr></blockquote>

You can see the different ones here <a href="http://www.majesticturbo.com/compression.html" target="_blank">http://www.majesticturbo.com/compression.html</a>

GaryK

I too was debating whether to get my K27/6 rebuilt or buy a Garrett. A KKK rebuild is typically $300-350 from either Majestic or TEC. I've had KKK's rebuilt for my Audi's before with good results. But, I really wanted a #8 hot housing for the K27 as well, which made the rebuild/upgrade price near the cost of my T04E.

My motor is nearly stock and I really have no plans to run more than 15-16psi boost, so the 46 trim should work efficiently. With a 2.8L and higher boost levels, you might want to go with the 54 trim or larger.

I'm hoping to get my car on a dyno soon and can provide the results, but unfortunately I never did this with the K27/6 even when it was working fairly well.

Btw, can anyone read the chart on Majestic's site to determine the DR and then the CFM for our 2.5L motors?

Dan87951

What is the main difference between the T04E and the T04B? I'm having a hard time reading the maps. Which would be the faster spooler with a #8 hotside? Really trying to get a sweet street turbo that will put in my seat as well. Been talking to Tim about a Stage 1 (T04B) 360 degree ball bearing with Stage 3 Trim, Super V compressor, and #8 hotside. I'm hoping to combine this setup with the mods I have in my signature. Will this make 310ish rwhp at 15-16 pounds?

David Floyd

[quote] What is the main difference between the T04E and the T04B?<hr></blockquote>

TO4E/TO4B/Stock, this should help some.

jimbo1111

WOW that to4e is much bigger than the to4b. Whats the differance in hp between the two and spoolup time.

GaryK

Ran my car on a Dynojet today, with a wideband O2 sensor hooked up as well. With 15psi boost, readings were 295 rwhp and 328 rwtq. The mixture got progressively richer, from 13.5:1 at 2500rpm to 12.5:1 at 4000 rpm to 10.5:1 at 6000rpm.

'89 951 - Garrett T04E 46 turbo, Autothority MAF & custom K27 chips circa 1994, stock injectors, fuel pressure at 42psi static, Bursch testpipe, Borla exhaust, rebuilt stock wastegate, MBC at 15psi -- otherwise stock

The fuel curve needs some work, but at least my Autothority chips were not too lean up top as they are reputed to be. Maybe at sea level the mixture would be proper. Could the problem be the rising rate adjustable fuel pressure regulator?

Dan87951

My gosh the T04E looks like a treat to install!! People actually get those things to fit? Unbelievable! <img src="confused.gif" border="0">

GaryK

Yes, it is a pita to install. Even after some grinding, bracket removal, etc, I still have the issue where the alternator interferes with a straight shot from the MAF to the turbo inlet.

And disregard my comment about the rising rate adjustable fuel pressure regulator. I have the Paragon billet aluminum one, which I now understand increases pressure at a linear rate.

So, I guess my chips are just causing the excessively rich mixture up top. There's probably another 30rwhp available with the proper mixture.