8.7 spring only hitting 6 psi
 

Well, I got my first tune and dyno on monday.

I have an 8.7 psi spring in, but the most they could squeeze out was 6 psi and 230 hp.

I have 550 cc injectors, TurboToyotas kit.

Any thoughts? I did do a search btw and didn't come across anything.

vac leaks or exhaust leaks at the wg?

They dyno shop tested for vac/exhaust leaks and said I didn't have any.

Well in that case, make sure you have the right wastegate spring :)

Haha I did, but thanks for the the "do'h" check. Gotta always check those first haha.

Well, when I get home, I think im just gonna triple check all my couplers and do the soapy water test to see if there are any larger leaks that maybe they missed at the dyno shop.

what wastegate r u using? tial???

Yea, it's a tial.

ive had this issue before... seeing as 35mm and 38mm wastgates use same size springs...i figure ill order a 8.7 35mm spring for my 38 and well it ended being good for like 6 psi if that...i just ended using a boost controller

i would make sure ur spring is an 8psi spring first and if anything get a boost controller and call it a day but also i would double check for any vac/boost leaks what color is ur spring do u know?

It happens to me cause of the stock axle back im running, but with my qtp open I get all of that 8psi and sometimes touches into 9psi.

Ok, thanks all. I'll check into all these suggestions and get back to you. First I'll check for exhaust/vac leaks one more time.

After that, I think it may be the restrictive exhaust. The kit came with an s-pipe, but I am running the stock midpipe with the cat and resonator and a tanabe axel back.

Are you sure it's an 8 PSI spring?

Boost leak?

Altitude? Couple this with a core that steals .5-1 PSI of pressure drop and you have a winner.

also what wastegate size? tial 38mm and 44mm have different color codes on their springs

Yea, it's an 8.7 spring, had the tuners dbl check and try one of their 8.7 springs to make sure.

Boost stays steady, doesn't creep or leak.

I'm in arizona, so no crazy altitudes.


I do have a small exhaust leak at the head that I need to fix. Passenger side lower corner isn't seated correctly and I have the stock mid-pipe with the restrictive cat.

I'm guessing it's the combo of the exhaust leak and midpipe.

It's the tial 38mm wastegate.

is it new? I had to take mine apart and clean it ... had a similar issue before.

Tried that as well, but didn't help.

are you sure they did boost leak test? or maybe they just checked your clamps if theyre tight or checked it visually? i had a huge boost leak and i still creep boost, 7 psi one 6psi spring

Yea, I had another shop check as well. They told me the midpipe as well. Sounds like that's the issue.