Quick setup run down:

Built B17
60-1 Turbo
750 Injectors
Ram horn manifold
Ultra Gate 38mm w/ 7lb spring
451whp

I noticed on my datalog that in every gear my boost falls around 6lbs and takes about 1000-1500 rpm to build up to 16lbs.

There are no boost leaks or leaks in the manifold.

Somebody I talked to said that changing to a 10lb spring would hold and ramp the boost quicker than the 7lb spring.

Is there any truth to that? I'm still semi new to turbo setups.
I hope this doesn't sound like a dumb question.

 

what boost controller are you using? i dont think the spring size is going to make any difference

 

AEM Boost Solenoid
Hondata S300 w/ Boost Options
GM 3 Bar

 

Are you lifting off the throttle when you shift?

It's kind of unavoidable to lose turbine speed if you have to lift...

 

are you using the boost by gear option on the s300?

 

Yes, I'm using boost by gear. 10, 16, 16, 16, 16

By lift do you mean not using full throttle shift?
Im not using full throttle shift, should I be?

Thanks for the input and help!

 

are you letting off of the throttle when you push in the clutch to change to the next gear? if so the boost is going to drop a little.

 

non bb turbos lose a lot of boost between shifts. unless you can shift pretty quick i dont think theres is much else to help it besides get a bb turbo.

 

I let off the gas and push the clutch, shift, and then hit the pedal again.

I didn't know I should be staying on the gas the whole way through.

Do a lot of people use the full throttle shift option?

 

Powershift that bitch.

 

what mani? boost creep maybe.

 

i do a full throttle shift sometimes on my 3-4 shift. you dont need to set it up on the tune but it would be nice to have the no lift shift limiter. ballin.

 

what pressure plate you using?

 

ACT Extreme

 

shift flat foot all the way through it will help the problem a little and can help your et's

 

with the trade off of blowing tranny's like crazy


the full throttle shift on most ecu's isnt adjustable enough to get it to do what you need it to do.

 

i agree. thats why i only do it on the 3-4 as its the easiest on the tranny then the 1-2 and the 2-3.

 

if you completely lift you're shifting slow

don't lift 100%, lift 50-75% if you're worried about your trans.

you can also setup your revlimiter to work as a shift limiter, just make it cut at wathever you want to shift it and pickup 500-1500 rpms lower. that way if you shift near the limiter you can keep it floored (or 50-75%) while shifting, once clutch goes in it'll hit the limiter right away dropping your rpms almost instantly a 500-1500rpm during your shift, making the shifting smoother and dropping less boost.

the amount of rpms you want it to drop depends on your setup and or shifting speed
figure it out and you can flatfoot it without a shiftcut while keeping almost full boost

 

Lots of good info guys.

Joe, you pointed out what I was afraid of, I can't afford to break trannys!

 

Are you using a lightweight flywheel? Light weight flywheels rev faster, but they also fall back down faster. A steel flywheel will give the rotating assembly more inertia and keep the rpms and boost from falling off as bad.

 

if you could maybe raise your rpm shift point.. i found that raising from 8000 rpm shifts to 8500 rpm shifts helped keep my 61 spooled.. i also have the .82 exhasut housing..