C38 vs R
KgPS .065/.08= 15%
12.5psi x 1.15 = 14.375psi

Are you saying the c38 lineup is kapped at 12/13lbs on this platform? Cause its not. The c38-91/92 flows 82lbs/min thats more than a pte 6266. We prolly only see 12/13 lbs due to the restriction of a 3" intake.

No, I'm saying that if your pulley is giving you 12.5psi on the 38 then the R will make 14.4 on that same setup. I doubt you are seeing restriction from a 3" intake.

That makes more sense. Either way there has to be a restriction of air flow somehwere, no? if a pte flows 74lbs/min and can achieve 16/18lbs of boost. Shouldnt the c38-91 achieve the same boost pressure or even better? Mayb im over thinking this..

Yes, rotrex already decimates all other sc units as it is in overall performance, I have had 0 issues so far and complaints, but sure will be interesting to see what this c38r can do

I’ll get my car on a dyno with the 80mm when I can and if it’s worth it to show some results, if not I’ll be waiting in the wings on c38r results.

What size is the outlet on the c38? If it's less than 3" then a 3" intake can't bottleneck it.

All outlets are 2.5"

They haven’t released any specs for the c38r yet....how did you get that comparison ?

What boost are you seeing with your 85mm pulley

I wasn’t able to get my car on a dyno last summer, bought another car in August so I didn’t get a chance, but I will try this summer once the snow melts to get it on dyno with both pulleys,85 & 80

Seat of my pants feeling with the 85mm was great, 1st gear is absolutely useless,that’s why iam rethinking gearing, only issue is the crash bar in front of intercooler, I think it hinders our cars a lot, gonna install FI crash bar this summer.

You don’t have a boost gauge ? And I was watching intake temps in 100 degree summer day and intakes were 118 degrees ... not sure if more air will change much .... I do have a water/meth kit sitting in the garage ready to go on and tune ... that should give me a little more

No boost gauge, new car took up my parts fund but I got my parts list ready for this year, my seibon vented hood did help a lot with engine bay temps and intake piping temps, I am thinking that having half the intercooler completely blocked can’t help anything but I could be wrong. I’d install the water meth if I were you cuz then you can add more timing, I was shopping for a system to. Here in Canada where I am we see daily summer highs of only 25celius so I can make big power but then traction becomes an issue, spinning isn’t winning

See first post.

That post has inaccurate info ....our current is .63 kg/s and the c38r is .80 + preliminary and that actual final spec is unknown ... and you are factoring the pressure ratio as if it would be the same ... where is would be 3.00 or better
https://www.bimmerboost.com/content....wer-capability

Jinxx are you on the pre order list for c38r?