What turbo for a mild 3.0?

[87turbodance]

I've been doing some research into what turbo I'm going to use for my 3.0. For the hell of it I was looking on Ebay for a t3/t4 or a full t4. After looking through all the ads I've come to the conclusion that I dont know anyhing about what different A/R ratios and trims do to the turbos performance. I've been thinking about going with a full t4. What specs would you guys recommend. I dont plan to ever exceed 20 psi but realistically I will probably stay around 10 psi. This will be for a single turbo setup mounted above the tranmission with a pair of maniolds constructed of weld els. I'm basically after a turbo that would be capable of 400hp but still spool decently for street driving.

Ryan

something like this maye:
http://cgi.ebay.ca/AiResearch-T04-T3...QQcmdZViewItem

[Frank]

That is a misrepresentation. Its not really a T3/T4 hybrid. I personally would not go with it.

I would call Chris Wright and go with a T3/T4 Hybrid Super54trim. Go with a 0.63a/r turbine housing. You could talk to gasketmaster and get a regular 54trim with a DDB center also.


Frank

[87turbodance]

How do you know that the ebay ad I posted is a misrepresentation? I'd never buy a turbo off ebay I was just using ebay to take a look at what's out there. So a t3/t4 would be the way to go for a 3.0? What about A 16g?

[Ondonti]

whats with the 54 trim?

[TurboGLH]

How do you know that the ebay ad I posted is a misrepresentation? I'd never buy a turbo off ebay I was just using ebay to take a look at what's out there. So a t3/t4 would be the way to go for a 3.0? What about A 16g?

It claims to be a t3/t4, but it's a straight t4 with a t3 bolt pattern. The give aways are the split tang and the turbine outlet.

A 16g would be much too small for a 3.0, hell it can run out of breath on a 2.4.

Taking this chance to pimp Franks Turbo Calculator, I inputed the numbers and got this.

Using a 3.0, 400hp 11.8 as the ideal A/F and a BSFC of 0.51 you get this

3.0/400hp/11.8AFR/0.51BSFC

Using those numbers it looks like a a true 20g (using a tdo6 turbine) would be a good choice, but you would need to input your desired AFR and HP and regraph.

[87turbodance]

Would a straight T4 be to much for the 3.0 to spool?

[Frank]

Not to much, but as I have told Brent in the past (before he went crazy wicked on us) that I think you have a more streetable turbo with a T3/T4 since these heads are posses.

When you say mild, do you think 300hp or 400hp? The 20g is a combo for both. I suggest a 54 trim as a baseline for 350 and very streetable and since I was hung up with a T3/T4 since you originally mentioned one. Not a problem.

And Chris, your the pimp...

Frank

[87turbodance]

basically I'm looking for a turbo that would provide full boost no later than 3500 but have the potential for 400hp down the road. In the beginning I only plan to play with about 5 psi to see how things work. Anymore than that and I'm looking at forged pistons later. I still haven't quite figured out how to read the turbo graphs. My wife will drive the car daily from time to time and I dont want her complaing about it

[Frank]

Well the 20g is what is ideal as Chris recommended.


Frank

[87turbodance]

They seem kind of pricey. I might just do the T3/T4 setup

[TurboGLH]

Not to much, but as I have told Brent in the past (before he went crazy wicked on us) that I think you have a more streetable turbo with a T3/T4 since these heads are posses.

When you say mild, do you think 300hp or 400hp? The 20g is a combo for both. I suggest a 54 trim as a baseline for 350 and very streetable and since I was hung up with a T3/T4 since you originally mentioned one. Not a problem.

And Chris, your the pimp...

Frank

What can I say, I think that the TC is the coolest thing since sliced bread. I use /mention it every chance I get.

[Wink]

I personally like the compressor map of the T04E 50 trim for the 3.0L motor. Great for a low boost application. And allows for hella growth for over 20 psi. Add that to a Stage III turbine in a .63 A/R housing, and I believe you will have a turbo that will give exactly what you're looking for.

Just my $0.02,

Wink

[87turbodance]

Would a 46 trim not be more efficient? Or am I looking at the graph wrong?

[Wink]

If you were to plot the graph with the motors required flow needs, you'll find that the 46 trim is highly effecient in the middle of the rpms. But it sorta falls off towards redline, going by the compressor's effeciencies on the map.

Brent already found out how horrible the 57 trim is at low boost. The compressor's effeciency just flat out falls off the face of the world at low boost. But sings nicly at higher boost. But since he's one of the select few with alot of mods that increase effeciency of flow, he's finding out that the 57 trim is starting to get outgrown by his motor.

The 50 trim has an extremely wide map. It will be just as effecient as the 46 trim down low. But it will allow for better, cooler boost in the upper rpms levels.


This is a 3.0L with the 50 trim at 6 psi of boost, roughly 240hp.


This is the same boost level with the 46 trim.



This is the 46 trim at 400hp.


And now the 50 trim at 400hp.



The only change would be how large of turbine and housing you use. Figure your max boost with a Stage III turbine in a .63 A/R T3 housing will definately be before 3500rpms as stated by the above graphs. But I think you'll get the idea.

[87turbodance]

very helpful. Thanks. I'm a little confused though. Are you talking a full T4 or hybrid?

[Wink]

those are just compressor maps. The way they spool up will be determined by the turbines. I suggested a T3/T4 hybrid. Something with a Stage III turbine and .63 A/R housing.

If you go with a full T4, then I'm afraid that the turbine will be too much for a streetable turbo setup. Ask Brent, He's running a full T4 with a T3 flange. I think he stated that he sees boost fairly early, meaning before 2500. But it doesn't come to full swing until 3500 or so. I'm sure he'll correct me if I am wrong on this. But I believe his turbo was a T04E 57 trim in a .60 A/R housing that was mated to an "O" trim turbine housed in a .70 A/R housing.

[87turbodance]

ok. That's what I thought. Thanks. I'm going to give my local turbo guy a call and see what he can do for me

[Ondonti]

Nope, I found out the turbo is a KKK k27 turbo. We arent sure what the turbine is. The wheel specs are the same as STage V wheel but the housing a/r is bigger then a .63 like most t3 turbine are.

Anyways, the k27 pushea little more air then the 50 trim (49lb/min) but has the crappy map shape of the 57 trim.
k27 is an "upgrade" for a lot of turbo porsche guys.

My boost wasnt full till 4000+ rpms but I have a massive exhaust leak in my manifold from a spot that didnt get welded. Im Fixing that hole with some 2000 deg epoxy.

Now, In 5th gear I would get a couple psi boost as low as 1700-1800 rpms...but..........

[Irocelectric93]

Brent...ive never asked you before but what are you spooling at?

[Ondonti]

Brent...ive never asked you before but what are you spooling at?

Depends what gear. in the lower gears I get a little boost around 2800 but I dont get full boost till a bit over 4000 rpms. Remember I have a large exhaust manifold leak I am working on fixing.

In 4th or 5th gear I can make boost below 2000 rpms but im not sure what the point is. I guess its cool cause i can climb any hill in 5th gear.