wondering what your thoughts are, im looking to purchase a Borg Warner 91-79 (part number 177275) and i have 2 turbine housing options (T4) either an undivided .88a/r or divided .91a/r. I am running an open t4 manifold... just seeing what you think, looking for around 700-725whp.....

 

i would run the open one just because of your manifold. i have used a divided housing on an open manifold on a customer car but he wasnt making over 425hp or so.

 

i used the divided s366 on an open full-race topmount no issues here at all, ran a 10.0 with it.

you could always use the divided manifold and SP quick spool valve on the open manifold and get about 100hp, 1000rpms sooner!

google sound performance or SP quick spool valve" on youtube

 

Anyone have any experience with the SP quick spool valve? Seems to good to be true.

 

just checked those out with some before and after dyno runs...if these really do what people are showing then wow.

 

I'm running an open manifold with a divided housing.

 

ok awesome guys, i just wanted to make sure. The .91a/r housing is standard on that unit and the .88a/r is special order and costs more money, so i was just concerned about saving some cash lol

 

the only experience we have with them is on the 6cyls but I can tell you this, its worth every penny, especially if you decide to get the solenoid and have some form of pwm output to it like aem has and can control how open or closed it is and such.

To be honest I would love to see something like this on a large turbo honda like say an s372, before and after.........

 

Having the turbo spool up faster is not going to make a difference at the track.

 

Really? Is that why 67mm cars are running as fast, or faster than S372 cars? A better power band always helps.

IMO, it's hard to control the boost when a lazy turbo finally comes alive, so much that people are putting 26" slicks on their cars trying to hook for 2k rpms. In turn destroying drive train all the time. With a better power band, you could control the boost way better and lessen the shock on everything. Thus longer lasting parts, and quicker et's. So unless your on a power glide, IMO spool does make a difference.

 

True stroy. At the IFO just here in Ennis we were the only 67mm (6765) and everyone else in the class that qualified was on S372's and we were spanking that *** all day. ALL F@CKING DAY! In qualifying alone we went 10.1@149 and the next car was a 10.4 on a S372. What they know about that 67mm on a stock bore getting it done?

 

dont mean to thread jack, but what about doing the opposite? any cons running a divided manifold w/ open housing turbo?

 

I originally ran an open t4 manifold with my s372R (1.25ar) and it made over 700 just fine but spool sucked. switched to a divided manifold and it was night and day. better spool and powerband.

 

I am running a open manifold with divided turbine housing and it wasn't bad at all. I have recently done a test and was quite impressed. I decided to port the turbine housing and sharpen the divider like the way you would on cylinder head ports. It spools about 500 rpms sooner on average. Before I did this the best my car would trap was 114 and now it is trapping 117!

 

+1

 

This is exactly what we did to our set up. If you port the turbine housing it will help when you use an open manifold!

 

It made a hell of a difference when driving on the highway. It hit's full boost (9psi) at 4k in 2nd gear now. You can just down shift and floor it and boost is there! I also got the manifold, turbine housing, and waste gate thermal coated and that was a vast improvement as well! I am trying to decide on what turbine blanket to get now. I was looking at T1's but I cannot afford that one at the moment.

 

wherers ken peak?

 

Ken is probably street tuning cars in China now, after ****ing everyone out of their parts and money with that Peakboost scam of a company.

 

ne careful on the porting in the turbine housings especially on the divided turbos, some of them more then other s will for sure develop more than standard cast housing cracks, they can actually develop rather large cracks in them and need replacing.

I did absolutely nothing to my 366, straight off the shelf on a full race t3 undivided manifold. car would make about 28psi on my dyno just after vtec(4800) I think I have a video somewhere of it on the rollers

 

We run an open manifold on a divided housing, works fine. As far as testing the different combos, the only difference was spool time on the 2 step, which can be minipulated anyways.

 

Absoutly the power band is very important......if a turbo makes its set boost at 5500 rpm vs a larger turbo making its set boost at 7000rpm. If you motor doesn't drop under 7k which it never does.... during a pass why would it make a difference. Totally agree the 67s are kicking ***. But its not because the boost comes on earlier. I could be completely wrong though

 

It seems like a lot of the outlaw cars turn anywhere between 9500 and 10500 rpm. Even with a stock GSR trans you wouldn't drop under 7k shifting that high. Hell maybe even an LS trans would be kinda nice with that much power and rpm! I like the 67mm turbo's for street use but the 72's I wouldn't imagine being very fun at all.

 

Roughly the same setup i have, minus i have a forward facing mani. what RPM were you seeing full boost at? I have the S336 .83 A/R.

 

Any back to back tests on this?