You are right, it would choke it down compared to a 10.5 , however - all the DSM Red models that ran 10's and even 9' used even smaller 8cm housings. So if you kinda look at this unit in historical perspective within the 4G63 realm, 9.0 isnt even as small as we have been stuck with in the past.

 

I don't remember really. I'm not sure we ever really operated it without a solenoid on the line to up the boost. We have on other smaller variants that would give about 17psi or so with no solenoid.

 

I don't know the history, do you remember the whp? e.t. and mph is hard to go on with so many people turning their dsm's into tin cans

 

This being all very true but without looking at a timing map it is unfair to say that the 100 octane wasn't also being used to take advantage of its anti-detonation characteristics versus 93. Hot is hot anywhere and I know from many years that 100 octane allows for more aggressive timing then straight 93 of as do you. Whether the ability to run more timing and possibly a leaner A/F was taken advantage of none of us know (even FP since all he runs is 100) . To hint towards that since it is was very hot and 100 octane didn't make a difference in the cars performance is very unfounded (if I am assuming/reading in to much then please forgive me). Especially considering the boost level compared to the ambient heat index.

Even so, if you were to lose 2-3mph from having to run pump it is still a very impressive mph known the less for the mods .

 

I was asking cause allot of the guys on the greens and wr's are trying to hold more boost up top by cranking down on the actuator. I was wondering if yours is holding pretty good set at 18 like it came??

 

This is the way to discuss an issue. Not by calling someone stupid or that they don't know squat from p-diddy (or was that p-diddley). Point is well taken.

 

That is the best reply I have read in awhile and the forums would be alot more concise/useful if we all took that approach. Very good .

 

Chris: A lot of peeps would say that your .63 housing is too dinky for the HTA 35. They would instead opt for the .82 exhaust housing as being ideal because of added topend potential. Some might even take it a step further and favor the 1.06 housed HTA 35.

I'll bet that 99% of the Greens leave FP's shop configured with the 10.5 turbine housing. I tried the 10.5 on my Green but I couldn't live with the relaxed spoolup(22 PSI@3400 RPM). So, I later swapped the 10.5 over to a 9.0cm housing. It now spools to 23 PSI by 3200 RPM. Which is O.K., but my goal was to get the Green to spool to 23 PSI by 2800 RPM. I figure that I can do it when I switch to the Forge WGA, an O2 dump, a fully ported 9.0 turbine housing and an HKS EVC-6.

Since my car is a JDM RS with the really short geared JDM(closer ratio) 5 -spd tranny, with high numerical final drive ratio, I need a very fast spoolin turbo otherwise I can't see max boost in third.

So, the possibilty of a faster spooling, tighter-housed Red is extremely appealing to me. I can live with the slightly higher EGT's, the slightly increased backpressure, as well as the possibility of compressor surge that I'll get with the 9.8 housing. In fact, me thinks that I'll order a Red /9.8 for my RS. Thanks, Roberto, for developing such cool turbos for us.

 

Have you measured presurre between wastegate and solenoid valve? When boost and rpm goes up, pressure to wastegate usually drops, since boost control tries to close wastegate. If pressure in wastegate line goes to ambient and boost drops, wastegate is too weak or the limits of turbo has found.

I have stock evo8 in 2.3l engine. After 5500rpm (22psi boost), stock actuator can't hold anymore. With FP 18psi actuator situation is better and it can keep boost over 6000rpm.

It would be intresting to see wastegate prssure curve on RED when there is 30psi boost, what rpm pressure in wastegateline starts to go down.

 

Do you mean to say that you have a stock VIII turbo on a 2.3 liter stroker motor? If so, then is it the 9.8 or the 10.5 cm turbine housing?

EDIT: What form of boost control device are you using.

 

10.5 hot side. I have bolt that to saab b234 engine (90mm bore, 90mm stroke, 9.25:1 compression ratio) with tubular exhaust manifold and full 3" exhaust. 630cc injectors. Boost control is done by self tuned stock ecu, boost controller is normal PWM based solenoid valve. That setup can produce with 98E (RON)
~400bhp.

Measuring wastegate pressure you can see how ecu adjust boost pressure. If you put boost and wastegate pressure in same picture it is easy to see how ecu tries to correct spikes etc.

Next year plan is to put RED with 850cc injectors and see what happens, and measure everthing

OT: Saab's have also 2.0 and 2.3 turbo engines and there is also this never ending debate wich one is better, no ultimate truth found yet...

 

clearly we have different goals as I'm more into drag racing and want a good trap speed so truly what happens below 5500rpm or so doesn't matter. The 9.8 might spool quicker on the Red but it's going to sacrifice power and that wouldn't be acceptable for what I'm into. I'm sure with a high enough octane that can be overcome somewhat.

at the time I bought the HTA 35R that's the way they came .63 later BR started selling them at .82 by default. Instead of changing mine to a .82 later if I don't meet my goals I'll likely just go to the next bigger turbo, maybe a 37R for a little more trap.

 

The long wait is over... she showed up today on my doorstep.. thought i would share a few photos

http://i181.photobucket.com/albums/x...o/Dsc02461.jpg

http://i181.photobucket.com/albums/x...o/Dsc02460.jpg

 

to the people who are receving the Red's now, did any of you guys get it ported/coated as well? I was told by FP that this might delay it a couple of extra weeks (lord knows how much in FP years).

 

Mines just plain jane...