turbo details and compression for b18c7 question

[VTi_b0i]

im using a garret GT28RS (disco potato) and its alot of fun on the street

[IEVAQ8]

tony, ur t28 s15 jdm spec bb turbo is a 0.64 rear housing........

on that t28 i would go for at least a 1.06 rear, even get it custom machined and fitted (bout $700) that inclkude machine work, biger exhaust wheel and balancing...........

i had the 0.86 rear, and i had same issues as u..............

[votek]

what rear exhaust housing have you got now?

[IEVAQ8]

im running a gt3037s with 0.82 rear housing.

and if u see my comparison with avo graph...............same response as a t28bb with 0.86 rear housing......

[votek]

whats full boost at for you tom?

[IEVAQ8]

whats full boost at for you tom?

Atm, the way my car is set up…………….coz im not running a boost controller………..

The more I rev the more boost I make………does that make sens…………

It makes 7.5psi, consistently after 7000rpm………

However I am on 5psi at 4500 rpm and its not laggy at all…………….just like my comparison avo setup to fullrace setup graph shows………..

Here is my full race and gt3037s boost graph

[votek]

yeah what you said was right. my limited was down to 7000 and when they revved it to 8000. it would push 11-12 psi

so they cut it at 7000 and told me to get a boost controller lol

[IEVAQ8]

that dont sound right on a internal gate...................or avo setup..........my avo setup was steady on 8psi no matter what revs...........and it was on full boost at 4000rpm.................

but with the full race manifold and external gate, the exhaust gases flow too well (if that makes sens) and causes over boost.

thats the probs i was having with 9psi spring it was opening at bout 10psi and over boosting to 12psi............

so with a 4.5psi spring its opening at about 5psi and boosting safely to 7.5psi

if i got a boost controller, i wouold be able to hold off on the boost till around 5000rpm and let it coe on hard and hold steady boost at 8 or 9 or whatever i wanted to hold it at