I have an '02 WRX and last year rebuilt my JDM 2 liter, the EJ207.

After the rebuild (which wasn't needed, I just got carried away, lol!) and after I got a base tune and a clutch to hold it ran 10.7 @ 136.2 mph, spinning horribly through 1st gear, only a 1.73 sixty foot.

I finally was able to get it onto a dyno to see what kind of power it was making with the GT3582R....

27 psi on straight 93, 461 whp / 330 wtq and on C16 and 35 psi, 603 whp / 420 wtq.

So... the car is fast. BUT, my friends 2.5 liter / GT3582R combo laid down (same day I might add) 631 whp / 489 wtq. So I am looking to do all I can to extract what I can from my set-up.

Ok... so the question... I am running the ported shroud compressor cover on my 35R. He is not.

In the EVO world... have there been any comparison's or real world experiences as to what difference the compressor cover will do to my set-up?

I have done a ton of reading... seems the general consensus is that all things equal, the ported shroud housing will add lag AND reduce overall topend efficiency.

So... assuming I do not run into compressor surge... the non-ported housing could potentially help me spool up a little quicker (currently, hitting full pump gas boost @ 4700 rpms, ie- 27 psi) and could give me a little more topend... in the order of 15-30 whp from the reading I have done.

That said... what are your thoughts???

Also, any real world spool-up and dyno numbers/graphs of GT35 variations would be appreciated.

def

 

Look into Forced Performance and their turbo line up. Any GT series they sell goes through some work and comes out a HTA. Just search any of Dave Bushurs threads and youll fine it or just as easily go to the site.

All I might add is that you'll gain in hp/tq and even better take less to spool. Check it out if you got the money you'll probably be sending in your GT3582 for a 450$ conversion to a HTA GT3582.

 

You are correct. Removing the ported cover will increase spool and top end efficiency. I have no practical experience with the 4G but with a lot with the 2JZ at the last shop. running non ported covers was standard practice after testing showed large improvements over ported covers. On 42 and 47r turbos where we could not get an unported cover, we actually machined the covers to remove the ports and then pressed in aluminum velocity stacks.

 

I have done that test man.. on my sr20det
With a 61mm wheel and 1,3 bar (19,5lbs) with the presicion ported shroud housing and the standard to4s housing
100--150 rpm on the spool up and 12 whp peak hp and over aprox 6-10whp on the powerband.
I will try to post the dynosheets ..the prob is I got All my dynos on my RIP old computer A friend its working right now trying to save all the info...Sorry
Forgot to mention that I did not experience any surge on both comp housings.

 

Thanks for the info...

def

ps- off-topic, how fast is the 240?

 

I know about the HTA's... and thats an option down the road.

But this is more about switching from Garrett designed ported shroud T04S cover to the standard Garrett, non-ported T04S cover. Just a simple compressor housing swap...

Thanks for the insight though.

def

 

Well hey, thats good info. What kind of peak numbers were you hitting? Boost pressures?

Thanks!

def

 

With my Talon, I see 30psi at exactly 5,000rpm in 3rd gear. It's a T4 with .68a/r (open) backside. A little different than what most people use. The compressor inlet is the regular 4"/2.5" (0.70a/r) with the bell inlet ie. no ported housing. Car made 541whp at that boost level on E85 rather easily on a 2-day conservative tune. 2.0L displacement. Car does not surge in any gear.

 

nice, whats it run?

def

 

Car had a junk trans in it that would not shift ...so crap times. I did manage to granny shift it to a 102mph trap in the 1/8th though at that setting. I'm in the middle of swapping in a good tranny so we'll see what it does soon.

 

The best run I can find hosted on YouTube HERE

 

nice! what trans is that? and is that an sr or rb?

theres an s14 around here with a manual and rb25. his best is 9.8 @ 152. pretty sick with wg dumptubes cut flush with the hood. fun cars man.

def

 

I used to talk to you when i had my wrx on nasioc..Well,i switched over to the evo.Bit, i still have my legacy gt..I hope that you find the info you are looking for... Justin

 

At 19,5 lbs with the ported shroud housing on a dynojet was 416-8whp and with the stock to4s 428whp (sc61 turbo 0.82 back housing) Now with a BW turbo .
Hope this help you some.
Cheers.

 

Traitor!! haha... just kidding. Glad to see your enjoying the EVO... thats what its all about.

def