Ok, I'm just playing around with some ideas here, but I need a couple questions answered. I was looking at a .50 Trim turbo like the SRT-4 guys use. They are making good power with them, and it seems like the spool times are decent. I'm aiming for around 350-400whp, and the compressor maps appear to be decent for what I'm looking for. So here are my questions:

1. Which A/R exhaust housing would be better, the .48 or the .63? I understand the .48 would spool up faster, but will it kill top end power?

2. Where is a recommend place to purchase one from? I've already looked at ATP turbo's site, but is there a place that is a bit cheaper. Looking to spend around $500-$650 for one.

3. Do you guys/gals have any comments on this turbo selection for an LSJ?

Thanks ahead of time, and let's try to keep this professional here. I am not a newbie when it comes to turbo and modding as most of you know.

 

AGP has a nice ball bearing 50 trim that spools real nice too. As for exhaust housing size, depends on where you want to make the most power in your rpm band. With the smaller housing it'll spool faster but you will lose top end power. Other way around with the .63 (which is what I'm running right now)

 

I would recommend going a little smaller turbo. The 50 trim from agp for the srt can support upwards of 500 hp (race gas). if you are only looking for 350 to 400 a smaller turbo will suit you a lot better.

Remember about the spool time. We have 2.4 and you have a 2.0 so spool will be noticably slower for you.

Edit: I see that you are fimiliar with mits 16G. You might want to look for 20g for your cobalt. If should support that hp you are looking for.

 

.63 here you go http://www.rogueusa.com/Garrett-T3-T...t-t3to4e50.htm


How about a big16g? Instead. You could have 2 16g turbo cars.

 

I'm trying to stick with a t3 style flange for ease of manifold access, so that's why I wasn't necessarily looking at the 20G. The thought did cross my mind however because I love my 16G.

On Full-Races site, they are rating the .50trim for 420whp. I will say that it should spool faster than Pauls' .57trim, and that is working great for him. I would say that I'm leaning towards the goal of 400whp more so.

Paul, how much top end are we talking about here. Do you think it would allow me to achieve my 350-400whp with the .48 housing? Thanks again guys.

Damn thanks for the link. I can get either the .50trim or the .57trim for $575! Nice!

 

try www.turbochargers.com they have awesome pricing on turbonetics t3/t04. i went with a .63 a/r and 60 trim compressor on mine. cost me 750.

you should talk with 06black about properly specing your turbo. he knows his stuff.

 

1. Your top end has nothing to do with your spool timing, it's all in relation to airflow. It just means that you'll have a more responsive lower end cause you'll have a high amount of CFM at lower RPMs because the turbine housing a/r is smaller (stronger exhaust velocity).

2. www.agpturbo.com

3. Turbo selection has alot to do with what you want. We all have preferences.

Also, referring to trims and not specifically what model doesn't help much. Granted, I know that you're talking about a T3/T4 type turbocharger but other people might not. Just a suggestion.

 

go DBB or dont buy one at all.

the .63AR houseing sits RITE on the surge line for our car so its just about "perfect" per say.

i run a larger houseing then that and my mid-top end is crazy and i only see a touch of lag on the 1-2 shift, 2-3, and 3-4 kick rite back into boost.

i'd go with a DBB 50T over a crap journal barring unit any day of the week.

 

I forgot about that. Good point.

 

Right on the surge line. Perfect. Maybe for VE but idk about perfect for performance.

 

Adam, you might wanna watch that first point of yours.

spool times have a vary direct relation with exhasut houseing.

if we keep the flange consistent(say a T3 in this case) then the .48 is much smaller then a .63 thats a given, however with the .63AR houseing being STUPID close to the LSJ surge line going smaller will choke out as the revs climb.

in short, the .48 will come in quicker but it will trail off in the upper end of the rev range, the.63 will take a marginally longer time to come in but you eaither wont suffer, or suffer vary little top end boost drop.

not directly on the line, buts its close. close enough that a good cold day will push it over that line.

however with that houseing, as long as you keep every thing else constant a houseing that sits in the max eff% island, fairly close to that line offers the fastest PR build up with minimal back pressure.

 

I guess depending how close. But idk if i would run real close to it though. I am assuming the af at redline is still on the island?

 

also do remember we can pull over 1000rpm more than the srt's do. I run a t3/t4 .57 trim with a .63 exhaust housing... 7400 rpm. does start to fall off @7k though

 

lol toward the right-upper side of the island

i jumped to a bigger houseing do to future plans and my concern thats the same as yours.

that i know my friend, i graphed the car at 3 different VE with the same 4 boost numbers and concluded an average.

 

I know this is about your turbo, but what happened with the twinscrew. If you want to keep it private please pm me. I'm very curious about the outcome.

 

If you want you can PM me about it. Like I said, I'm just weighing out my options. I haven't necessarily given up on it yet.


Ok, I at a decent level of understanding here, but you guys have just blown me right out of the water. I guess I need to do a lot more research on this. Great input thus far gents, please keep it coming.

 

i take it you got sick of waiting for your TS? Still waiting on my package aswell...

 

If you give me a call bro I'll explain.

 

I saw your post and I forgot about that. I corrected myself.

 

you know i'm just playin with ya Adam, your one of the few people i'll bother to listen to!!!

 

yes.

Alright if u want 400whp get a dbb 50trim with a .63 thingy...

Agpturbo.com is a prettyy good site and reliable and are very friendly to help out and who sells the 50trim turbo alone, not sure on the price but img uessing around 800 or so.

 

not just a 50trim tho........sooo many viable options for a relatively "low" power goal

 

Why is the DBB so much better than the journal?

 

faster spool

 

Well I know that lol
But it is still a bearing...