racer rx

Hey Guys...

I just got my 7 our of hibernation. Last year I had it street ported and noticed that the port gave me a little
more lag... The primary turbo kicked in at 3400 rpm or so.
Then the secondary at 4800 - 5000 rpm with a great jump in acceleration and a little wheelspin.

I've been changing the pills in the wastegate to give approx. 13.5 -14 pds. of boost. Yes I do have the usual
mods... ECU/IC/intake ect. ect.

Does anyone know how I can bring my primary turbo on line quicker than 3400. The primary seems so use-less. And does not give me the get up and go.

Any suggestions?

thanks jc

maxcooper

If you lug the car in fifth gear with your foot on the floor, what RPM are you running when you hit 10 psi? My car with 90K mile turbos hit that at about 2600 RPM, and 2200 RPM with reman turbos and a fresh, mildly ported motor. I think the RPM also depends on ambient temp and other factors, so I don't know how useful a precise comparison is, but your numbers should be in the ballpark.

You might have a loose wastgate actuator (not sprung tightly against the seat), or have lots of cracks in the wastegate valve seat that are preventing the turbo from spooling up when it should.

It seems like porting should make it spool up a little faster, if anything, as the exhaust port opens earlier. It sounds like you have other problems.

-Max

Yenven

I just got a new street port motor to.
My turbos do almost the same thing,but the first one comes online were it should but the number two comes on around 5500rpm.

Im going togo rip all the intake off and see if all 3 of the Actuators work how they should and look over all the vac hose for leaks.

BTW does anyone know what happens when u make the actuator rod longer or short,i see were u can turn it to do it.

racedriver

I lost all boost respone below 4500 rpm on my new streetport with non sequential. It was non seq. before and would pull at 3000 rpm?? Did anyone port the exhaust a certain way??, possibly creating an overlap.

SPOautos

I think some of the larger street ports cause the velosity of the air flow to slow down eventhough its moving more air. Some shops streetport is basically just a "clean up" job not really a big port, it doesnt really affect much. If your low end power decreased a little its prob due to a big port job which will help you at higher rpms like you guys are seeing. When racing you dont fall below 4500 anyway so it shouldnt be to much of a prob.

just my .02

STEPHEN