I bought 2 of these brand new for my denali twin turbo project. I thought I'd post here since many of you guys are more knowledgable about turbos and specs than I.

They are garrett turbos brand new in the box. They are t04b25 per the sticker on the boxes, PN 409770-5019, I'm told they are new old stock from about 3-4 years ago.

The compressor housing is .60a/r and the turbine housing is 1.15a/r with a 3" outlet. I'd rather be running something like a .84 on the turbine housing since these are going on a 6.0L v8 and I am aiming for fast spool, not top end (the engine has about a 5.5krpm redline). Obviously to change the turbine housings I need to know trim specs etc, this is what I need help with.

The turbine wheel major dia. is 2.87, and minor dia. is 2.51 or thereabouts.

Can anyone help further ID these turbos and recommend where I can get 2 tangental divided t4 turbine housings in a .84 or similar?

 

Whats up Kevin,

Garrett T04B25, U-Trim compressor, a little smaller then a V-Trim. The turbine wheel is a P-trim. Was OEM turbos for NAVISTAR diesel trucks. High vloume low pressure unit, should work ok with your engine at low boost levels. It'll be laggy with those big *** turbine housings, but give it a try. You can't really take full advantage of divided turbines on a 90 degree V8. If it were a flat plain crank set at 180 you could. If your going to get new turbines, get some open valute or non divided housings. .81 or .68 would do it.

~Mike............

 

Mike do you happen to know where a compressor map is for that turbo?

 

Was just trying to dig one up, I can't find it. I've built several hybrid turbo's using those compressors. I know they flow less then a V-Trim, I believe in the neighborhood of 48 lbs per minute MAX, 25~30 being the sweet spot @ 1 bar. I'll continue to look.

~Mike................

 

Thanks for the response. I thought about PM'ing you but I didn't want to be bothersome so I'd just wait for you to respond when you saw this

I thought they looked like diesel turbos due to the massive turbine housings. I plan to run them at 5-12psi and make 450-500awhp. I dont really want to bother with installing them in a complex space-restricted setup (I have to custom fab everything) only to have to take them back out when I am unhappy with spool. I'd like to go on and change them now, not to mention that the smaller housings would probably help with fitment and fabrication in the engine bay a little bit.

Where would I get the other turbine housings? IF you can supply them i will gladly buy from you, perhaps you can make some money along the way. What is 'open valute", is that just another term for non-divided?

 

I stopped selling turbo parts a while back and lost touch with all my suppliers. Your gonna have to do some searching if your looking for a good deal (eBay). Any T4 P-Trim housing should work, stay away from on-center and stick with tang. Valute is the opening to the turbine or disscharge of compressor housings. Open valute is just another way of saying non divided.

Those turbos are a dime a dozen and have been selling here and tons of other forums as well as ebay. Theres Chiniese knock off's of those things now too (ala SSAutoCrap). Hope you got em cheap. The same turbo has been manufactured by Garrett, AiResearch, and Borg Warner, all having same specs, just different names on the copressor housings.

Your Denali should hawl *** after those suckers are installed.

~Mike............

 

http://cgi.ebay.com/ebaymotors/Turbo...QQcmdZViewItem

A bit higher then I expected, maybe they'll cut you a break cause you need two.

~Mike..........

 

hmmm...their title says .68 while their description says .58.

So, does the turbine trim come into play when buying a turbine housing, or can I simply order the a/r housing that I want for a t4 and not worry about it?

If I could get 2 housings and 2 vband setups for 400 then I'd be happy with that.

I got both turbos brand new for $700. After checking around on ebay and turbo supply sites for a LONG time, I could not find any small-ish t04 turbos that were not chinese for under $700 each, so I thought that $350/each was a good deal, even though the turbine was not what I wanted. Both the turbine housing and the compressor housing both say Garrett, and the box was garrett also, thus I am sure they are not chinese.

So given my application, you'd recommend a t4 undivided tang .68 over a .81?

Thanks for your help, btw. IF you have any use for the existing divided t4 1.15 turbine housings that I won't be using, they are yours, just say the word.

 

I noticed the .68 and .58 descreptency also. I'm sure its a typo, even if its not, I'm sure those guys can get whatever you want. Email and haggle with them, make them the offer of two turbines and v-bands for $400. I do it all the time. Infact, I can't recall every paying retail for a single thing except food and gas for a long time LOL.

I'd stick with the .68 A/R (or even smaller). Don't let the massive exhaust engery of the rotary sway you when dwelving into piston wourld. Even some grand national guys run T3 turbines on a single turbo and make good numbers (3.8 ltr V6). Although you have roughly 3 liters of displacement per turbo, your redline is low and I'm sure that engine is optimised for low end torque. I'm sure your going to want instant spool and essentualy make the truck feel like it has an even bigger engine, and the smaller A/R turbines will do that.

You MUST match turbine housings to the turbine trim. You have a P-Trim and its most likely been clipped too, all the more reason to go with the smaller A/R.

Thanks for the offer man, but i have a couple of those monster turbines laying around too. Pretty much useless for most applications except diesel. Even on the rotary its a bad match, if someones looking for more top end, they should have a bigger compressor, and if they have a large compressor, that should be matched with a larger trim turbine too (Q-Trim) thus negating the huge A/R turbine.

Keep me up to speed on your project man....

~Mike...........

 

Kevin, Here's Treadstones email address. His name is Jason and He replies back every time.

info@treadstoneperformance.com
Also, check out their website as they have everything they sell listed there.