hey guys, this is a log of my 4th gear pull. from 2500 rpm it hits ~30 psi at 4000 rpm
tha car is 2.3 with S2 cams, true twin scroll manifold, 7 blade HX35 with 14cm TS T3 hotside

im interested is it a good spool for 2.3 ? what will give me swapping to 12cm ts housing ? is it worh the hassle ?

Sounds pretty good

Keep that housing, with your displacement and 30+ psi boost you need to let her breathe.

I thought 12cm housing was already pretty big to be choked and maxed out even by 2.3

Nope. Really rough numbers, but 12cm^2 nozzle is going to translate to something like 0.9 A/R. This will behave like a ~0.55A/R open housing of the same flange. Fairly small.

I think its spooling slow. that same turbo with 12cm ts on the 2.0 spools 400-500 rpm faster. 2.3 is worth 400rpm spool. so in effect this setup is spooling 800rpm slower than it could. I also think its possible the 14cm is adding lag and not power. you can go too big on exhaust housings.

From personal exeriance I can say that the 12cm is to small. The 14 is still probably too small. OP what does you manifold look like?

^

it's custom tubular one, 44mm ID runners

I think its spooling slow. that same turbo with 12cm ts on the 2.0 spools 400-500 rpm faster

Click to expand...

94awdcoupe

so you are telling me that 2.0 spools hx35 at 3500 rpm ? where it spools stock turbo then, at 2000??

http://www.dsmtuners.com/threads/hx35-dyno-264-272-vs-272-272.403784/
target boost always precedes peak tq by about 300rpm. so this setup was likely hitting full boost around 3600.

"Spools" to what boost and in which gear? Those are the sort of qualifying details that are crucial to statements on spool being of any use for comparison.

Also need to consider if the car you're trying to reference against is FWD/AWD, its total weight vs. your weight and pretty much every component of the powertrain play a part in boost threshold.

If there are a lot of mutual details, and there's still a big difference in results.. it's time to verify mechanical timing, boost/drive leaks, look into the tune, clogged cat, collapsed flex section, etc.

If it's none of those, are you comparing to someone at Sea level where you may live somewhere prone to high DAs?

~500rpm is nearly negligible in that respect.

agreed there are far too many factors left out. so much that its not worth debating. a dynograph on a dynojet would be first thing needed. but from his log it looks like it will hit peak tq around 4300. thats around 400rpm slower that the 2.0 12cm graphs that are easy to find. doesnt matter what gear the 2.0 pulls were done in. because if they were done in 3rd then the op car is spooling even slower.

Timing advance will also play a roll during "spool up".