what about porting the exhaust part of the head with oversized exhaust valves, that should increase spool....assuming no porting is done on the intake stuff.

i think it would be a waste to pull the head for that without a full port job though, the trade-off woudln't be great enough to justify leaving the intake unported.

and, nitrous, LOL

 

higher compression can spool the turbo faster... but then you need good quality gas...

 

Superchager.....HaHaHaHa

 

I have seen Shiv, Martin, and ATP all sing the praises of the 3071 (in each of their own kits) but I am yet to be convinced it spools significantly better than the big power 30 series, aka, 3076/and Vishnu spec 3037. So, there must be something to really like about this turbo besides it's initial spool up. I'm assuming they really like it's responsiveness between shifts, etc.

Good luck on the spool issues. The 2.3 stroker kit is the single thing that will transform your car to a spool monkey. But you are looking at at least three grand with labor...

 

I've been lucky enough to track test most of the turbos out there and I have to say on pump gas I like the 3071 best (over stock (03) through 3037's and 35r's). I wonder if all 3071s are all the same internally(?). the of course you have to figure in the exhaust manifold and if there is a cat or not. The one I drove had 91oct, ported head, 272s, no cat and it was a 2.0l and it was making full boost under 4k and spooling at 33 or 3400, it felt damn strong and very well matched to the 2.0.

Smoggy, that was the shop car at the photo shoot...

 

IIRC, the 3071s are not all the same. We tried different hotsides on my car to try to get it to spool sooner, but all we managed to do was lose power with the smaller one. At the time my 3071 was installed, Martin at AMS also said that it came with a newer hotside than previous 3071s.

So far I like my 3071 a lot, although I do wish that it held on just a little bit longer up top. I can't imagine what a 3071 would be like on a 2.3 ... it would be an incredible street setup, although personally I'd probably go with a 3076 for street use on a 2.3L 4g63.

l8r)

 

i know when i get my set up it will be the 3076, i've heard nothing but god things about that turbo kit, I took a ride in a 2.3 gt35R and man that thing feels like it has no lag.

 

When you said you lost power with the smaller hotsides did you loose torque as well? That may be the trade off, a little less peak but more "area under the curve"(?)

 

Remind me to post a comparison chart later ... I've got the dyno run files for the comparison (conveniently located at home, of course).

l8r)

 

Here you go. Comparison of the smaller hotside vs larger hotside on the 3071. To be fair, the difference is a little bit more dramatic, since the final tune reflects different cam timing, but even with the same cam timing, the larger hotside was 25-30wtq ahead of the smaller one.

l8r)

 

Thanks, BTW that was a long work day , it looks like the smaller housing simply has too much back pressure but you'd expect it to spool better than the larger at the low end(?). Were you running the same boost? good stuff, thanks again

Hey, you wouldn't happen to have a stock turbo/similar mods run to overlay as well?

 

thanks for the comparo .. I was wondering if I had gone too small with the housing now .. looks like my suspicions were correct .. I was just too afraid to go bigger in case of too much lag ..

I'm using .64 now .. what did you upsize to ??
The other thing I'm seeing strangely is also boost tapering .. shrug .. either that or the engine is not making power up there anymore

 

If I were to leave the WG at the same setting, then boost would taper with the 3071 on my car, but it is no problem to dial it in to hold boost all the way across the rpm range. Seems that with the 3071, torque will start to taper off past 6000-6500 rpms (depends on your setup ... i.e. cams, etc).

I think I'm using a .63ar?? Martin would have to confirm that, as I wasn't paying attention when they swapped it back.

l8r)

 

Chrono, comparison dyno graphs for the different stages of my Evo are here: https://www.evolutionm.net/forums/sh...1&postcount=50

The one thing that the 3071 graph doesn't show is that it now pulls all the way to 9000 rpms ... I got Shiv to finally flash it for a 9100rpm fuel cut.

l8r)

 

how do you dial in??as in change springs or boost controller settings?

so you are back to small housing then? thanks

my torque tapers around 6500rpms.. this shows how the torque looks like (not a dyno!)