dont you just love efi live makes things so much easier. if only u had an lb7 you could run roadrunner and re calibrate the ecm while driving it

 

I pulled my Dmax mechanic buddy on a tube at 60 once, was a first time rider so he had no idea of the normal pulling speed. LOL...

Ya wanta barefoot, no problem, what's the world record for barefoot'n??

 

hahaha awesome..

idk but if i get my hands on that boat itl go 100

 

Ok guys while waiting on my drive parts to arrive, I did some more digging on this turbo and air flow.

I pulled the heat shielding and found it's a 1.06A/R housing, not .85 or .95 as I previously posted. Also found the T4 pedestal gasket is leaking, not real bad but everything under there was soot'ed up. What else I found is my MAF is filthy, oil coated and probably impacting readings. No air filter on this setup, so she flows unrestricted but has been sucking in some soot from exhaust leaking, and a little oil from a filler cap leaking at high R's.

Came inside and did some digging into older logs with the previous MAF unit before adding the velocity stack to the elbow tube. Found the MAF readings were about 5lbs higher last fall vs today.

Compared some older data logs before adding the velocity stack and found one with 48.8 lbs.min at 3000R's @ 42.8 Boost_DMA. At my elevation, baro is 14.5. So 42.8/14.5 = 2.95 correct?

On the compressor map I've charted a rough operating range using that as my baseline from stock tune logs vs what I've posted above with more fuel, knowing MAF is probably reading a bit low now, we can see about what this turbo is spinning. Not getting close to max turbine speeds.. Humm...



According to our map, she is far from being maxed out. Operating in the 72-74% efficiency range if I'm reading this correctly. So I did a little more digging on this unit and found the 4 & 6cyl ricer guys don't get very good performance out of this unit either. Garrett rates it up to 5.7L engines and 800hp.



To me this says it should be operating higher up in that charted area, being the Dmax is 6.6L and with more air moving. She is not spinning near the max RPM if our MAF and boost readings are anywhere near correct. I'm even leaving some room in my estimates for the pressure drop at the cooler. Which I guess I'll verify by checking pre-cooler pressures when I check the drive pressure. Something just not looking correct here??

Then I look at what a Honda tuner had to say about his unit, and it matches what I've been told by some diesel guys.

Guessing that noted back pressure problem could be my EGT issue correct? She does good on temp with less fuel and RPM's. Above 3200R's and the 2000us tune she jumps quick on the EGT gauge pushing 1700.

Which brings me to what unit has been suggested by a buddy, a GT4202R. However that is not a water cooled, and I'll need to redo the exhaust from a 3" to 4" v-band style. Not a big problem, but would still like more input on this before considering a move. I don't think I'm making over 750hp yet, so what would be advantages? More air and less heat? If so, would probably be worth the swap..

-K

 

i just noticed the charger you have only has a 67mm comp wheel inducer. my buddy has a custom work stock charger on his lly that has a 68mm cast wheel thats been clipped down to 64mm then it has a 66mm turbine but its got one less blade then the stock turbine wheels do. the housings are stock other then the mwe groove has been opened up all that it can be. on stock injectors i got 52psi of boost at 50psi of drive pressure by tweeking the vane limit table. when the vanes open up on that charger you can really feel it pick up the power.....i really think that your drive pressure is going to be well over 1.5:1 when you get gauge hooked up and i think thats what is holding you back.

 

Yeah that's the consensus of most big HP guys I know. We'll know in a couple days.. When PPE opted for that 4094, I think it was more about reliability and keeping the heat down in the engine compartment over making big power. In 06 that was probably a decent turbo option.

What you think about the 4294 specs? My goal is to open up the exhaust flow and lower EGT's vs making 900hp. Some are saying go with the 4202 and 1.28 trim, I kinda like the map of the 4294 with 1.28 A/R. Is like 1 step up from where I am on the compressor side, with much improved exhaust flow. I only need a 400 more rev's and a little less heat, satisfied with the power and spool times now. Heck if it would run WOT at where it is without melting down, even that would be super..

-K

 

what does it have for an intercooler?

 

interesting.
K... random question but do you have an external oil cooler?
those garrett compressor maps are very conservative. but if you want that turbo to last forever keep it in the map.

im just puzzled by the low boost. hopefully fixing that exhaust leak willl take care of some problems.

 

but the 4094 is a good turbo for a guy who drives it on the street with normal rpms.

youre spinning double of that most dmax guys cruise at on the high way. so something like a gt42 would do awesome

 

The intercooler is custom, about 32"x24" with 3" in/out water over air unit. See pictures below.

I've never checked the pressure pre-cooler vs after, that's on the list when we check drive pressure. Have cleaned it once and looked pretty free flowing inside, but who knows. Works good at cooling, you can always lay your hand on the exit side tube, the other side will cook ya..

Yes it also has a larger than stock external oil cooler, and temp gauge. Actually runs cool [about 180F] normal unless your spinning some rev's then it touches 200-210F. I don't think the exhaust gasket is much of a performance issue right now, she still makes more boost than it did when I first got it. New gasket is in the mail.

As you can see in the pictures, I moved the cooler away from the turbo, lengthened the tubes and built a LB7 style 3" intake. Spool time was greatly improved with these changes, boost increased at the intake by about 2psi.

-K

Before
After