Or he could do as you have and go the 2.4L displacement route. That is easier to fit in the engine bay than a V8. JaJaJa

 

What seems strange is that the OP mentions having tried a 7640 equipped car but goes on to state that he was not satisfied with its power, spoolup or transient reponse in comparison to that of a stock IX turbo. His assesment just doesn't make much sense to me. From all reports that I have read, the 7640 is at least equal to if not better than the IX in terms of spool and transient response. Furthermore, by all accounts, the power potential of the HKS turbo is unquestionably superior.

 

how did a 7460 not fill the bill? Guy here in germany has one making 450whp with ridiculous spool. The maf goes nuts when he's in 5th and loads the car up in low rpm.

 

You could put a TME Core (with 15G compressor wheel even) into an Evo 4 9.0cm2 exhaust housing for ultimate response.

It will not make the same power as the Evo 9 turbo though.

Response and power go hand in hand.

 

I have V8 in the other car thank you.

I'm not looking for smaller turbo. I'm looking for bigger but technologically better turbo (say BB aftermarket vs. JB stock) doing more HPs but w/o lag. I don't think it's unresolvable task as say Evo IX stock turbo would exist with BB cartridge and ligher wheels (magnesium/titanim) it would be what I need.

 

HKS spools faster but has bigger lag. For track and autox I did better on Evo IX stock turbo.

 

Can you put some numbers with this-- so you are at full boost when with your ix?
You are at full boost when on the HKS?

You want the numbers to be what? and at what RPM?

You didnt address the others mods you have or cams you are running, both effect spool and transient response almost as much as the turbo.

When I first got my HKS it was a little laggy compared to the stock viii--tuning and cam timing changes made all the difference in the world.

 

I agree with the above observations from a person who has tuned for the turbo in question. I too get the feeling that perhaps the OP is judging the 7064 without trying to maximize his particular setup. If it is on a Mivec engine then the tune is critical especially with respect to valve timing and igntion advance. Also, the HKS turbo is especially demanding with respect to adjustment and proper setup of wastegate spring pressure due to its idiosyncratic almost funky, segmented actuator rod configuration. Finally, we are not told about the particular DV/BOV setup on the car in question.

In short there are a number of factors that can affect spoolup and response on any turbocharged setup. Proper setup and combination become almost as important as turbocharger selection.

 

Ah, I was wanting to think of saying something like this. Why go out of your way focusing on a very small, trivial portion of the whole story. For what it's worth, going from 90 WTQ to 300 WTQ at full throttle in 0.5 seconds (with <120cuin) can cause headaches.

Most stock fitting rigs already spool rather laglessly, and with NLTS it's only one time from 1st to whatever. Sacrifice some carbon and there's none at all.

 

I agree Mike that there will always be that inverse relationship between spool and power output. I tried the 9.0 but I personally prefer configuring with the 9.8. The 9.0 is just way restrictive. Too tight as to scroll radius and too constricted turbine inlet area.

I think that the 9.8 is a better all around compromise for quicker spool. Almost the same spool as the 9.0 but doesn't sap as much power. I think that the 9.0 is best relegated to duty on the old slush-box automatic tranny wagons.

EDIT: Sorry for digressing off course with my OT commentary.

 

Sure. Full boost was at ~4000 rpm and peak of torque near 4000 rpm as well. Nearly 2 bars. Now actuator needs fixing so I don't run the car ATM

I run BC 272 cams, nVidia o2 housing, downpipe and Trust titanium catback. FIC 1100 cc injectors and DW300 pump. Big APS intercooler. Drop-in filter.

 

Get rid of your garbage mods first such as the brian crapper cams and invidia O2 housing and you'll be well on your way to what you're looking for

 

Last artifacts I keep from previous owner I'll go for GSC cams and custom titanium housing and downpipe soon. Can we still talk about turbo?

 

2.4 LR BB Green on e85 35psi with aggressive timing. Sledgehammer response and torque punch

 

All thats been said here-- in summary, there is nothing thats going to get you better transient response then the turbos mentioned here, BBK Lite, HKS, fp/wht/green, tme etc.. all are small stock based turbos that will do what you want and all mentioned in the above posts. You do need to dump the cams-- the
O2 housing I think is fine-- I use it without problems and have for years now-- you need to get a good set of SMALL cams with lots of lift to maintain lowend , maybe even a split duration hks 272i/264e, and cam gears to get the intake advanced--since you have a ix i dont know about the exh gears.--again for low end--and you will be in the rt place. I am at approx 15psi at 3k and 27psi at 4k on the same turbo and the jump from 3-4k is instant, car is spooling at 2k easy. Any turbos mentioned in this tread should net you similar results if you match the rt components with the anticpated usage and power band. my .02.