Turbo setup indecision

[Calan]

I've read several threads, but I'm undecided on what to do with my turbo setup. I've got the car torn apart for a tranny rebuild and other stuff, so figured I'd fix some turbo issues at the same time.

I'm planning on 375-400 hp on a semi-daily driver/weekend cruise-around type car. (mod list is up-to-date I think). I would prefer quick-spooling "torqey" fun from stoplights rather than a high rev/max power type of setup.

I currently have a Big16G with stock O2 housing and mani, and a Megan Racing 2.5 to 3 inch DP. The DP BARELY bolts to the stock O2 housing, so I want to upgrade that to better accomodate the pipe and get better flow. My stock mani is cracked (of course), so it's going as well.

I'm leaning towards a rebuild, porting, and bigger flapper on my 16G, a stock Evo III O2 housing, and a stock Evo III exhaust mani. The only problem I've heard about is the slight angle difference on the O2 housing which may cause me DP alignment problems... any way around this or other solutions?

Any comments or suggestions on this?

 

[romeen]

I am currently running my EVO 3 O2 housing with a Bushcur DP that is not intended/angled for it. You can make it work but it does put a good amount of stress on the flex section and I would imagine the exhaust manifold-head studs as well. Although my DP has held up with this setup for the last 2 years I have an RRE DP with the correct angle for the EVO O2 housing waiting to go on.

Instead of putting more money into your B16G you might want to consider putting that money towards an EVO3 16G. Although it doesn't flow a whole lot more air, the lighter compressor wheel makes for quicker spool and a harder boost hit. In summary, more area under the torque curve. I don't know that it will get you to your HP goal but it is a fun DD turbo and hard to beat for the money.

 

[gsxtacy]

Or quit messing around and go 50+ trim....

I recommend either the SCM 5031 or the SCM 6152...

 

[Calan]

I was kinda looking at the Evo III turbo option also romeen, but didn't mention it... It looks like I could pick one up from FP for only around $100 more than the cost of rebuilding my big16G.. which actually is in pretty good shape any way (no shaft play or anything).

I may go that route and just sell my B16G. I'm still worried about that DP angle though... Just bought the damn pipe and had my exhaust cut and rewelded to match the flange at the other end....and hate the thought of having to replace it already

What about some slight machining on the DP flange or O2 housing flange? hmmmm...

 

[Calan]

Or quit messing around and go 50+ trim....

I recommend either the SCM 5031 or the SCM 6152...

Nah... from what I've seen and heard, I think a smaller/quicker spooling turbo would be more fun... and I'm all about fun over pure power and time slips

 

[Steve93Talon]

Why are you rebuilding your turbo? Is there anything wrong with it? If it's trashed, I'd buy the EVO16g over rebuilding yours (you can always sell yours as-is on ebay to cover the difference in cost).

Throw some mild cams in there and a meth kit and you'll make 350-400whp with that setup. Just pick up a used 2G manifold and port the outlet to match the 7cm housing. You can even find one already ported if you look hard enough. If you want to spend $200+ on a manifold, look into the new FP one.

I'd skip the EVO o2 housing and just get a tubular. You can get them for like $75-150 with either internal or external dump. I'd also not do the bigger flapper, just port your wastegate passage if it's creeping past the boost level you want to run. To reach your goals with a 16g setup, you're gonna be running enough boost that creep wont be an issue anyway, and the big flapper will just make boost fall off up top.

 

[Rice Over Wheat]

Nah... from what I've seen and heard, I think a smaller/quicker spooling turbo would be more fun... and I'm all about fun over pure power and time slips

I had a AGP BT28 w/ 17 psi actuator which is pretty much the fastest spooling turbo that is bigger than stock that you can buy @ 2500, full spool at 3000. Now I have a Bullseye T04B 50 trim and tial 38mm that spools at 3100 and reaches full spool at 3800. If you think that is slow spooling... Of course, the borg warner core is newer technology than the PTE/SCM turbos and spools quicker. Kind of between a journal and bb turbo. And they are cheaper as well.

To me, it's more fun to have that kick in the back that continues beyond 7500 rather than tapering off like smaller turbos. My turbo is always spooling at 3000+.

 

[v2ner]

I had a AGP BT28 w/ 17 psi actuator which is pretty much the fastest spooling turbo that is bigger than stock that you can buy @ 2500, full spool at 3000. Now I have a Bullseye T04B 50 trim and tial 38mm that spools at 3100 and reaches full spool at 3800. If you think that is slow spooling... Of course, the borg warner core is newer technology than the PTE/SCM turbos and spools quicker. Kind of between a journal and bb turbo. And they are cheaper as well.

To me, it's more fun to have that kick in the back that continues beyond 7500 rather than tapering off like smaller turbos. My turbo is always spooling at 3000+.

Big turbos are only good at higher speeds/gear while smaller ones are only good below. Your second gear will never be the same again. On the other hand third on up will be amazing.

 

[Calan]

Now I'm leaning towards the EvoIII mani and EvoIII O2 housing, but keeping my Mitsu B16G instead of buying a new turbo ($$$ that can go elsewhere). It doesn't have any shaft end play, but has very minor "chips" on the exhaust turbine. (I don't think it's enough to affect the balance or performance, but I'm obviously no turbo expert).

I'm thinking I'll just clean it up and maybe port it to match the mani and O2 housing where needed.

Comments?

 

[Rice Over Wheat]

Big turbos are only good at higher speeds/gear while smaller ones are only good below. Your second gear will never be the same again. On the other hand third on up will be amazing.

It's not the speed, it's the torque curve vs rpm range and the amount of airflow for the same amount of work. Smaller turbos deliver power sooner in the rpm range but fall off quickly at the top of each gear.