Experiences with GT/GTX 3582??

[momento1]

I didnt get any response to my previous thread about peoples thoughts on what size turbo i should consider between either GTX3071 or GTX3076 (currently i have a GT3071 with 0.63ar

so...

putting some feelers out there for any info or dyno graphs of anyone who is using or has used a GT3582 or GTX3582 and with what A/R...

Im interested more so in spool/boost plots cause im trying to understand what the average RPM people are seeing their desired boost.

Ive searched around the forums and on others and can see some people getting 25-27psi by roughly 4500rpm.. but cant confirm what A/R they are using or with what supporting mods....

Im trying to ascertain what i would be expecting because then i can try and relate it to my build with my mods and hope to lower that threshold.

I will be on E85 fuel so i can hopefully see better spool anyways and becasue im building the bottom end and installing adjustable cam, im aiming to increase my timing and further reduce the boost onset...

[gnutz2]

GT3582R with .82 hotside I see 1bar at about 4500 and 2bar at about 5000, this does vary with gear.

That's on a fairly standard engine, 8.0 CR and both 7a cams.

[momento1]

Wow... Only 1 bar at 4500.
Is that on purpose to delay the boost onset?
Maybe im wrong but that seems pretty late onset.
If thats normal then its definantely not the turbo for me

[Error404]

The issue you have with the .63 on the 3071 is surge, so you have to map more conservatively around that. You can go with a .82 hotside and not loose anything really low down and make more up top.

[momento1]

Yeah you are right
Previously i did get some surge with my gt3071 and 0.63 rear but i now went standalone ecu tuned with 7a cams and e85 fuel and it is a dream to drive.
I get about 25psi at 3700 and 28psi at 4000 and keeps pulling hard all the way to 307kw atw at 6500

I just wanted to go to a slightly larger and more efficient turbo for that kind of boost level without losing a lot of spool time too much past 4000

Thats why i was considering just going to a gtx3076 even cause it was easier to bolt straight into my existing 0.63 rear.
However if the 0.63 is going to pose a problem once i change my cams over to a more aggressive 267degree from 034 then i may as well start considering the next size up which is the gt35. But only if its not going to be a lag monster. Hence why im interested to see what people have achieved with the gt/gtx3582

[gnutz2]

Wow... Only 1 bar at 4500.
Is that on purpose to delay the boost onset?
Maybe im wrong but that seems pretty late onset.
If thats normal then its definantely not the turbo for me

My setup operates the wgfv at 100% duty when boost is building to hold the wastegate fully shut.

That's typically what I see in 3rd gear, 1st and 2nd will build boost slower and 6th gear will do it a lot faster.

looking at a data log when I was testing I see the car did 1 bar at 3800 in 5th gear on one run, but if i told you the turbo could do this it would be very misleading because in that situation you would normally change down 1 or 2 gears and be on boost straight away.

Another reason is the turbo always surges like crazy around this boost/rpm area, sometimes its a loud chirping and other times it can make the car violently shake, which has just reminded me i need to change the turbo map so the boost cant rise that quickly in the higher gears.

HTH

[A80Avant]

If you want the best of both worlds then go for a GTX3576 with the 0.63ar. Still have to change the hotside anyway. That could put you close to 550ish with no much better spool than a gt3582 with the 0.82ar