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Discussion Starter · #1 ·
OK, I've convinced myself my turbo's to damn small after coming up short while trying to get upwards of about 2.4 bar absolute boost acording to the ECU logs. High EGT's and crappy timing says it all. I think I've hit the point of seriouse diminishing returns.

So what's the deal, some say the BB turbo's take longer to spool, some less time. Is it possible to get new technology that will be on full boost between 3500 and 4k rpms, and still flow 500 hp? Anyone want to let me "test" some different turbos for them :wink: :wink:

Current turbo:
Garrett 50 trim t04e/stage III t3 turbine.

If I do this, the trick head will go on with all the goodies everyone's been talking up, I'll have new flanges welded on the DP and header, and probably vent the WG to atm. I gotsta give you 20vt punks a run for your money :eek:

This projects never going to be over :D
 

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well, javad told me they aren't really worth it for the money, but that's pobably just in my situation :D . anyway, glad to hear you want to stick with the 10v, we gotta hold onto our roots man :wink:
 

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Jim,
What's the atmospheric pressure where you are? There's a good chance that after your air filter, and the thin air up there, you're going past the 3.2-3.4 pressure ratio limit on the compressor.
Hook your megasquirt MAP sensor to the inlet of your turbo and see what the inlet abs pressure is at 7000 RPM at max boost. I bet it's pretty low.
Nothing Garrett other than the T70 or T72 can go past a PR of 3.4, time for a Holset :D
If you're not passing the 3.2-3.4ish PR limit of the 50 trim, then the problem is definately your restrictive exhaust housing and wheel.
This is exactly the reason I would suggest buying a new "whole" turbo, not a mix and match of components. Don't buy something with a smaller housing than Garrett designed it with, or you'll have huge amounts of back pressure, and high EGTs as you do now.
Check to see what kind of pressure ratio you're running the turbo at to get 2.4 bar. If it's under 3.0, then I'd go with a GT 30, new and complete. Not some retarded GT30 with a T3 housing that "spools up faster" because it'll choke you like the one you have now. The new GT exhaust wheels are a ton more efficient than the old wheels, giving higher boost pressure at lower RPM, while still flowing better.
The Holset exahust wheels are on par with the new GT series, and the compressors are far beyond the Garretts for anything needing high pressure ratios.
There is a guy on the net with an HX 35 on his 2.3 Ford (uses a T3 sized flange by the way) Starts going around 2500 RPM and makes 26psi by 4000. That's what's going on my car next time around.
So do some testing, see what kind of pressure ratio you need. No point in getting another turbo that won't work for you, and unless you test the inlet pressure and compare it to the outlet pressure, you WILL NOT know if the turbo you are going to get will work, whether someone says it will or not.
Good luck out there 8)
 

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Discussion Starter · #4 ·
Mike, that's the best freaken advice I've recieved in a long time, and gives me a ton new ideas. I've all but forgot about the Holset's.

I'd like to try some type of ram air system. Hap just told us about his ram air sytem that he built to help the same PR issue. It makes 8 psi in the air filter box at 80 mph. Hey, anything helps.

I'll try and see what kind of ratio I'm looking at. Those Holsets look pretty cool.
 

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hey, i know this isn't the same subject really, but, in this diesel magazine that my dad gets i saw an ad for a dealy that's kinda honey comb lookin' that goes in front of the turbo to stop the air from swirling or something like that. supposedly it helps reduce lag.....i dunno though. maybe it's something worth lookin' into??
 

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audifreakjim said:
Mike, that's the best freaken advice I've recieved in a long time, and gives me a ton new ideas. I've all but forgot about the Holset's.

I'd like to try some type of ram air system. Hap just told us about his ram air sytem that he built to help the same PR issue. It makes 8 psi in the air filter box at 80 mph. Hey, anything helps.

I'll try and see what kind of ratio I'm looking at. Those Holsets look pretty cool.
Holy crap in my pants! 8psi at the airbox, that'd pretty much make up for thin air anywhere you could survive.
The HX 35 operating range is up to 4:1 (~45psi at sea level) with flow capacity good enough for 500hp (50lb/min airflow) Really broad operating range too, the surge line is 130hp at 15psi. Since Javad made more than that at the wheels at around 3500 RPM, I'd say you shouldn't ever cross the surge line.
I've got the info packet with the compressor map in PDF if you want it, it's on the Holset site, but it's a pain to find after they redesigned the site a while ago.
Give the ram air a shot, but my guess is that your exhaust housing is killing the party. Do me and yourself a favor, measure the exhaust back pressure at the turbine inlet at your HP peak RPM and 20psi. I wouldn't be surprised if your back pressure was over 50psi, definately not good!
You can get a brand new Holset for about 400 bucks on ebay......
 

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Discussion Starter · #7 ·
Yea, I saw that turbo on ebay, looks pretty nice.

Anyone want to buy a solid t4/t3? :wink:

God damnit, I want that turbo now, and don't want to F with changing the header flange. Any bright adapter plate ideas? Comon Mike, make me something that you can turn in for a project. I'll give you an A+ if you need my input :D
 

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Just weld the turbo straight to the manifold, done deal. :D
 

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audifreakjim said:
Yea, I saw that turbo on ebay, looks pretty nice.

Anyone want to buy a solid t4/t3? :wink:

God damnit, I want that turbo now, and don't want to F with changing the header flange. Any bright adapter plate ideas? Comon Mike, make me something that you can turn in for a project. I'll give you an A+ if you need my input :D
Yeah Jim, the adapters are easy, problem is they take a few inches, and the Holset's are HUGE. I'll print some drawings out though, see what I can think up :wink:
I'll let ya know tomorrow. I imagine you would like to do this without taking the header off the car?
 

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Mike is great! Only posts when its really solid info...Awesome. Your user name should be E.F. Hutton...everyone listens :D

Aaron
 

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Jim, keep us updated on this holset turbo information.

I think a header and a larger turbo will be in my future sometime in the next year or two, and these turbo's sound like they have great bang for the buck in 300+ horsepower applications, and they have modern wheel and housing designs to boot.

I might be able to get holset flanges made if you need them, I have a contact with a shop that can laser scan in a file from a gasket, and laser cut them for a reasonable price. Let me know if you need help on that.

I might also make a set for myself (gotta set up some projects for the TIG welder I treated myself to last month).
Brian
 

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Hey Jim,
So here's the deal.
First, the exhaust flange is the same as the Garrett T3, so that's easy to come across. Since the 5 banger can't split into a divided housing well, you'll need to grind out the bridge, like the guy with the 2.3 Ford did. Look up his page to see. FWIW the HY35 has a smaller exhaust housing, better spool up, and is undivided. Bolts directly to the T3 flange. I really don't know which would be better, both the HY35 and the HX35 have been used by the 2.3 Ford turbo guys.
Second, an adapter flange would be at minimum 1 inch thick, and more likely 1.5" thick. If this is acceptable, I can make one, or tell you how to make one, but I doubt there'll be room for the turbo pushed out another 1.5"
I've got the flange drawings here, or they're on the Holset site too.
 

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Discussion Starter · #14 ·
Thanks Mike, I don't think I have room for an adapter. Well, a little more info. At rest my baro map sensor in the ECU reads 81kpa, so yea, that's some thin air, and at 2.4 bar that puts me at 3:1 PR right? I'm thinking ram air is in the very near future.

Also, next time I have the head off, I'm going to have a T3 flange put on the header. It's pretty much the standard for everything, and I'm pretty sure you can get the new GT series with a T3 flange without compromising anything right?

How does the non-wastegated downpipe bolt pattern compare between the T3 and K26?

Also just got back from the dyno, and figured some stuff out. I'll start a new thread on that.
 

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Yep, that's just at 2.9 PR, pretty darn high, even higher after the air filter etc. The non wastegated one has 4 bolts, like the Audi one, though I bet they're farther apart, check out the drawing in the PDF...
I'll check out the dyno thread...

audifreakjim said:
Thanks Mike, I don't think I have room for an adapter. Well, a little more info. At rest my baro map sensor in the ECU reads 81kpa, so yea, that's some thin air, and at 2.4 bar that puts me at 3:1 PR right? I'm thinking ram air is in the very near future.

Also, next time I have the head off, I'm going to have a T3 flange put on the header. It's pretty much the standard for everything, and I'm pretty sure you can get the new GT series with a T3 flange without compromising anything right?

How does the non-wastegated downpipe bolt pattern compare between the T3 and K26?

Also just got back from the dyno, and figured some stuff out. I'll start a new thread on that.
 

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ATP cast up some custom GT housings with a T3 flange on them that bolt up to T3 applications (what we used on Christian Miller's car), but it costs about $1300, so not a cheap turbo.
 

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Javad,
what did you think of the GT? Everything and more? Or marginally better?

Aaron
 

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Well, as in all things, you get what you pay for, but you don't always get twice as much for twice as much money.

I think the new GT's are by far the best turbos on the market, they combine the best of all the advances in turbocharging in the most recent past. But, for $1300, a GT30 isn't twice the turbo of a $700 T3/T4.

The GT30 will make more power sooner, however, I think where they shine is in efficiency esp. when compared to a T3/T4. In fact, the GT30 is the same turbo used on the R8's, only difference is the addition of water cooling and a thicker casting for the turbine housing.

If you have the budget, I'd definitely consider it (this doesn't include you Aaron, unless you manage to get one for free, which wouldn't surprise me :wink: )
 

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Cool! I think I'll stick to my hybrid for now,unless I find a GT for free..haha
Javad, are you using a GT on your 20V project?

Aaron
 
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