T3/T4 with ar.48 Has anyone else done it?

RB25SX · Post by **RB25SX** » Wed Oct 22, 2008 6:07 pm

I got a T3 .48 exhaust housing for my T3/T4, to see what differance it will make to throttle responce and lag. Std T3/T4 usualy comes with T3 .63 exhaust housings, but I found that it has a lot of lag on the SR20, starts boosting at 3500 and full boost over 4000 rpm. I wil fit it tomorrow to see what the differance is. Will have to be mapped again, and dyno'd. Will try to take it to drags on friday night to see how it does. My previous time was 13.3. Does anyone use a similar turbo setup?

AR 200SX · Post by **AR 200SX** » Wed Oct 22, 2008 8:45 pm

will start boosting a bit earlier.i am running the same setup.

RB25SX · Post by **RB25SX** » Thu Oct 23, 2008 5:44 pm

Drove the car today, and the smaller Exh housing does make a differance. Turbo spools up faster, but not much lower in the rpm range. Full boost from about 4000 rpm. Maybe remapping of the feuling will make a differance also. Will get it on the dyno tomorrow, to compare dyno prints.

AR 200SX · Post by **AR 200SX** » Fri Oct 24, 2008 7:12 pm

thats what you want,mine starts boosting at about 3500rpm right to the top.

phoenix s14 · Post by **phoenix s14** » Fri Oct 24, 2008 8:54 pm

Yeah no this is informative... I have a T3/T4 on my SR and it suffers from the same problem... only boosting from 3500 and full boost from over 4000

very interested in your results bud... 1 more question...

Are you running a bearing centre or not??? Am considering doing this as well... want boost from 2000 and full boost from +-3000... any ideas what else to change on the turbo to get it spooling any quicker???

please post those dyno results

Doctor G · Post by **Doctor G** » Sat Oct 25, 2008 9:42 am

phoenix s14 wrote:Yeah no this is informative... I have a T3/T4 on my SR and it suffers from the same problem... only boosting from 3500 and full boost from over 4000

very interested in your results bud... 1 more question...

Are you running a bearing centre or not??? Am considering doing this as well... want boost from 2000 and full boost from +-3000... any ideas what else to change on the turbo to get it spooling any quicker???

please post those dyno results

A little birdie tells me on a sr to run a t61 with a 0.48 AR ex housing, together with a stage II or 0.58 trim compressor wheel, and he reckons it boosts from between 2300 - 2700rpm already, and at 3000-3500 its on full boost already making 200kw to the wheels, and then of course makes some serious power up top.

Only he reckons the gearboxes don't like this so much. Then again, this was fwd, so maybe the rwd box can handle it....

RB25SX · Post by **RB25SX** » Sat Oct 25, 2008 12:31 pm

Yes, this was a interesting test, I use a normal bush turbo, not bb. Had it on the dyno yesterday, looking at the print with .63 and .48 dyno runs u can see the differance. I decided to keep to 1.2 bar compared to 1.4 bar on the .63, only because of reliabilaty. I am sure on 1.4 bar the .48 housing would give the same 405nm but on a much wider powerband. On lower boost I lost out between 4300- 6000 , but gained a bit between 2500- 4300 and ended almost the same on top at 6500 rpm. I ran 13.2 again last night with less power, must add that the tail wind might have helped a bit. From my experience, on a SR20 with std cams, a .48 exh housing works better on the T3/T4 setup. Feels a lot more responsive on the road.

n1smo200sx · Post by **n1smo200sx** » Mon Oct 27, 2008 8:45 am

I also run a .48 housing at the back with a close to T61 front-KKK.
My boost comes only at 4500 rpm but it hit really hard and revs up to 8200.Made 207rwkw at only .8 bar.Will try to see the difference at 1.2bar soon.that sr still stock cams? Cams will also help with response but tnot biiger than 256 on the std valve spings to be safe