95 TSI AWD Project VGT Holset no 56k - Page 5 - HomemadeTurbo

aero · 09-25-2008, 05:15 PM

Quote:

Originally Posted by Turboedmav

Hi there! This is my first post around here... I have a few questions and I hope you can help me...

I am turbocharging a Ford 5.0L, shooting for nothing over 12psi and slightly under 450hp, which is the known limit for the stock block and I was considering the twin-turbo route using a couple of Garrett VNT25's, recent research suggests me that even a couple of them would be undersized for this kind of displacement as they were originally bolted onto 2.2L chryslers and they were already quite restrictive on the exhaust side...

Seeing this Holset being used on a 2.4L I can't help wondering if this turbo isn't really a bit oversized, just asking for my own research, I don't want to get anyone offended here!...

if this turbo works well on a 2.4, one could easily be mislead into thinking that it would probably be a little undersized for a 5.0L, which I tend to doubt given this unit is originally installed by Dodge on 6.7 diesels

.

Leaving gas engine EGT's alone (that's a whole other issue) I don't know much about the differences in exhaust flow between diesel and gas engines.. I mean, does a diesel engine produce substantially more exhaust gases per displacement unit than a gasoline engine or are they about the same?... I'm asking all this because I'm trying to figure out if I should dump the twin turbo idea and just go for one of these turbos for my 5.0... too small? too big? can anyone please cast some light on this? I'm all confused now... thanks.

Sizing is a bit different, and somewhat of a mystery with these. Not many people have tried somethintg like this. Given the spool and response I would say it is not oversized for what I am wanting to do. I am looking for the ability to make 450+ eventually, so this is the best responding turbo that I could hope for.

Compessor size wise this thing is slightly smaller than a GT35R, a 60mm inducer. Similarly sized holset compressors in a small shitty BEP housing have been pushed to over 600AWHP at VERY high boost.

For your bigger motor I have to wonder if a HE431V would be a better option. It has a larger turbine wheel than the HE351ve that I am using. The VGT doesn't close down as far, and opens further. Should still spool stupid fast with 5L and when open make more power at your low boost goal. The one I had had the same compressor wheel as the HE351ve. The flange is also very close to a T4 flange, the holes on the turbo had to be dremeled out a bit to fit a standard t4 manifold. They are a bit more rare on Ebay, but it would leave your turbo options wide open if it didn't work out as expected. The 431 we picked up for ~$220 shipped, you just have to wait a bit to find one.

Turboedmav · 09-26-2008, 06:27 AM

Thanks Aero,

I know you must be sick of us turbofreaks asking you about the (probably overemphasized) dangers of the combination of VGT's and high EGT's... but the fact that almost every piece of literature from the manufacturers explicitly discourages the use of these units on gas engines makes me feel the urge to ask yet again.... sorry... are these turbos being underestimated? are the VGT's manufacturers just buying cheap insurance by telling everyone these turbos shouldn't be used on gas engines? what's up with that?

What do you think of my possible twin set up with the Garrett VNT's?... I am bent on this idea because I believe these turbos were actually good, just not well taken care of when they came out as OEM, I'm robably wrong, but I guess I'll learn the hard way... ... ... my reasoning has been: If the turbine is a bit undersized for this project... why not putting them farther away from the head... Every turbo "guru" out there says turbos should be as close to the head as possible for best performance... but if your turbo is going to be getting more exhaust energy from the engine than it can efficiently handle, why not giving the turbo a smalll break (in terms of temperature only, that is) by putting it some 30 inches away from the head? From my perspective, it would help keeping temperatures down a bit and probably reduce my chances of overboosting... after all I'm not shooting for high levels of boost in a stock 5.0L... I am definitely going to install wastegates as well but I'm thinking electronically actuated ones with... ... ... exactly the same kind of actuator you didn't use in your set up! (the valves themselves will be like electric exhaust cut-out valves already in the market, but those are controlled by a DC motor, not a stepper...cool right?)

I know that Megasquirt 3 has now the abilty to operate at least one stepper motor (for the IAC but can be programmed for any I/O) I'm planning to use this output to operate the stepper on these actuators... I know, I know... sounds unnecesary and probably stupid to use a mechanically actuated VNT when you have a neat way to operate the electronic version... ... ... ... why bother fabricating an electronically actuated wastegate if you could operate just the same actuator on the HE351VE and save yourself two hundred headaches... ... ... gues I just like to dick around and learn the hard way just like yourself...

So, for those of you who want to tame one of these actuators... there it is... the Megasquirt 3 can be programmed to do it.

Many aspects of my project are still undefined, and, in the end, I might just drop the twin turbo set up and slap one of these to my 5.0 (I searched the net and Holset says they're good for up to 7.0L... ... so I guess there's really no need to go any bigger since as I said before, the boost will be kept very lowm my HP goal doesn't really call for anything beigger and the engine is completely stock...

(are you going to sell me your actuator

or will I have to surf the net for one of them?

)

TomBones · 09-26-2008, 11:01 AM

So have you been able to control boost with that wastegate and control spool with the VGTs pretty well so far or are you still dinking with it. I was going to try to make a simple manual adjustable arm for the VGT for now. That way I can adjust it until it works for me. I may decide to put a wastegate actuator on the VGT also once I find out how much of a difference the VGT makes by moving it manually.

screamingdsm · 09-27-2008, 02:35 PM

Thats a nice setup man, glad to see some dsmers are getting it done. I too have aem powered g4cs 2.4, and i have a big turbo sitting waiting for the time to put it on. Its a 25cm turbine housing with a weird turbine flange.

CspecRun · 09-27-2008, 07:34 PM

That's a KKK right?

aero · 09-27-2008, 10:36 PM

Quote:

Originally Posted by malichite

So have you been able to control boost with that wastegate and control spool with the VGTs pretty well so far or are you still dinking with it. I was going to try to make a simple manual adjustable arm for the VGT for now. That way I can adjust it until it works for me. I may decide to put a wastegate actuator on the VGT also once I find out how much of a difference the VGT makes by moving it manually.

Still have some more things to try and work out. I want to build another MBC to try on the VGT actuator to see what it does to try and speed the spool back up a bit. Lost a little bit after I hooked the VGT actuator up rather than keep it closed, but it still has much more topend and still better response than anything else I've tried.

Here is a 1st through part of 4th pull and the boost control/response, with it the way I have it now.

It still needs a LOT of work tuning wise, I keep changing little things that put me back at square on in the tuning progress.

The oil actuated garretts I don't like because of the much greater compexity especially in the hot areas of the turbine housing. The fixed vanes on the movable back plate should conduct heat away much better than the movable blades in the garrett as well.

One of the concerns people express about the garretts and high EGT's is the possibility of the vanes sticking because of thermal expansion binding where they pivot. The holset moving parts are located in the oil and water cooled center section.

I do know of at least one person who has used a powerstroke VNT in a similar manner to what I have done. I don't know how it worked in the long term for him as I can't find the thread again.

screamingdsm · 09-28-2008, 01:18 PM

Quote:

Originally Posted by CspecRun

That's a KKK right?

yeah, or a borg warner s370. Its all the same specs. 71mm inducer 100mm exducer compressor wheel 83mm-73mm turbine wheel

Tom-Guy · 09-28-2008, 01:45 PM

Holy shit, those are some high IATs.

aero · 09-28-2008, 03:01 PM

Yeah. It should make way more power when I get the intercooler put back on the car. The only thing saving me is the E85.

Running the piping to the one I had was going to be pretty hard with the huge compressor housing and outlet facing the pass side. I've been contemplating selling it, its not the most efficient IC with too small of outlets, and getting an A/W setup.

screamingdsm · 09-28-2008, 07:31 PM

Quote:

Originally Posted by aero

Yeah. It should make way more power when I get the intercooler put back on the car. The only thing saving me is the E85.

Running the piping to the one I had was going to be pretty hard with the huge compressor housing and outlet facing the pass side. I've been contemplating selling it, its not the most efficient IC with too small of outlets, and getting an A/W setup.

You ever think of putting another pump inline like a bosch 044? Im pretty sure on e85 your gonna run out of pump on that turbo. Whats your timing map setup like as of right now?