Hey guys. I want to share my experience with superchargerrebuilds.com and hopefully you can save a big headache. In January my Rotrex C38 started making a whining noise. After some research, I found that only two shops will do rebuild of this type of S/C. 928motorsport and superchargerrebuilds.com. I choose superchargerrebuilds.com because they can install a bigger compressor wheel plus the rebuild. I talked to this shop, they said it will take 2 to 3 weeks and they fix them on regular basis. I sent over my S/C to them early this past January. After four weeks without hearing anything from them, I contacted the shop and they apologize for the delay and I should receive my S/C in two weeks. After 3 months waiting and over 15 emails and phone calls, I asked them to sent me my S/C back. They said the same story again and asked for another chance. Another month goes by, I contacted them and after a few back and forth, they said my S/C was ready, really?. Their only way of payment is by check, so the same day I sent them a check by mail for $1,150 and a copy by email. Another two weeks go by and no S/C. I contacted them again and proceed to tell me that my S/C will be mailed the next day. Three days later, I receive my S/C and I was very happy.
A few days later I proceed with the installation following the AA instruction manual and the car started right up ( I change the oil, drained the fuel, spark plugs, fuel filter, fresh fuel etc..). I do around 10 miles avoiding boost to let everything warm up and get up to temp. I go to an empty area in Mexico, I'm in second gear around 2,500 rpm, I started pressing the gas pedal. Around 50% throttle and just 4,000 rpm, the car hesitate and shut off. The car fire back up but, something is wrong and no boost. I get home do some basic diagnostic and all seems fine. I took the belt off and the elbow from the inlet of the S/C. The pulley spins but, the compressor wheel is stuck. I contacted superchargerrebuilds.com and they proceed to tell me that I abused of the S/C, there is no way to know I'm telling the truth and that the form that I signed for the job says "no warranty" but, they will be happy to rebuild the S/C for another $1,150.
Learn from my mistake. Stay away from them.
Last edited by G60MM; 07-14-2020 at 02:32 PM.
Wow. What a nightmare.
What legit place only takes a check? This way you couldn't get your money back via a CC dispute or PayPal.
'98 RMS stage 2+++++(491whp/390tq VAC cams, CES Cutring-9:1, Built blower, Meth etc)
'09 Saab 9-5 Combi 5mt 1 of 1(Built Motor, Brembos, LSD, the works!)
'22 Cadillac CT4-V BlackWing 6mt
'22 Cadillac CT4 2.0T Sport AWD (wife's)
This has been happening for years we them and rotrex superchargers. I've had them rebuild one for me alot of years ago. Same thing but when it shut off would start back till I removed the belt. The supercharger was jammed. Rotrex superchargers are non re buildable. Learnt the hard way.
Sent from my SM-G960U1 using Tapatalk
the only place I'd send one is back to rotrex themselves... I could've sworn they offer rebuild/refresh services?
Oh wow, this is still happening!?!?
I had a similar issue back in 2010!
I sent in a Rotrex C30 that had a busted propeller shaft. Start out with their on-site web address that was something like 'superchargerrebuild.com'. I hadn't notcied it, but after a few emails, the email address had changed (though they copy and pasted the entire email chain into this new email) was something like 'superchargerrebuilds.com (note the added s at the end).
They used this tactic to ignore me for months, as I was sending emails to the wrong email address. Luckily I somehow caught the sneaky tactic, and emailed back to their original email.
At this point in time they responded, semi-promptly, and I informed them that I had learned a lot more, that the SC was not rebuildable, and that I simply wanted my unit back, and the initial payment refunded. Weeks go by, no communication. I finally get a hold of them, and they send me a tracking number. A package of about the right size arrives, but lo and behold, it is a C30 SC, but an amalgamation of SC parts that were not mine!
I email them back, tell them I have photos of my SC after it was removed that clearly show the housing being in pristine shape, pulley being in excellent condition, wear on the propeller, etc. They apologize for the 'mistake' and ask me, on my dime, to send them back the package and they will get out my unit.
A month or so goes by and I finally receive my original SC, though there is no refund of any kind.
TL;DR - superchargerrebuilds is a scam. Fuck those guys with a cactus. Sorry this happened to you.
"1991 332is - 1998 Supercharged OBDI S52 - E36 5-Lug with E36 M3 Brakes - B&G Coilovers - 2.93 LSD - Style 5's"
Gone but not forgotten
"1997 M3"
Currently being restored past its former glory
I recall reading a few stories of similar shenanigans over the years from people trying to repair or upgrade their rotrex's from this company.
928 motorsports rebuilds my chargers, very proffesional and never any issues, not sure if they rebuild rotrex though
Last edited by Boostedtincan; 08-09-2020 at 02:26 PM.
Wish I had read this before I sent them my blower. Mine's just a Vortech though. Hopefully, they send it back soon.
~Trey
00 540i/M6 Forgelines, M-pars, and boom, Oh my.
Hey guys, I end up saving for a year and bought the C38R-112. The biggest C38 available. Let me know if you are interested on this build and I'll post details of how to make it work, problems and results.
Big Rotrex. Could be fun. Does it fit existing BMW Rotrex C38 brackets?
Absolutely post details! This is going to require a lot of custom plumbing, and yeah I would imagine a different bracket..I'm curious to see how this will fit. The power potential has to be huge!
MODS: AA SC'D Rotrex C38-92 Stage 2 (60# injectors)==M50 Manifold==Snow Performance Stage 2.5 Meth Kit==Schrick 264/256 Cams==AA Ceramic Coated Headers==AA Trackpipe==Eisenmann Race 2x76==Clutch Master FX250 Clutch==Euro Oil Cooler==MANN Provent 200 Crankcase Catch Can==AA DSB== X-Brace==ZKW 6000K HID FX-R retrofit with Orion V2 L.E.D. Angel Eyes==Euro clear signals and tail lights==M-Tech Pedals and E-Brake==BBS RGR Diamond Black 17x8; 17x9 staggered==Leather Z Gauge Kit (oil temp, oil press, voltage)==Rally Road Guage Pod (steering wheel mounted with AEM AFR guage and Prosport boost gauge)==Cut-ring head gasket==Head refresh done by Autohead Performance==KW V2 Coilover Kit
Current with 85mm pulley and meth: 450 whp 365 wtq @ 13 psi on a Dynojet at Performance Eurowerks in Buffalo Grove, IL.
Previous: AA Mustang Dyno Tuned in Miami, FL @ 10 psi on 93 pump made 392whp 325wtq (Performance Eurowerks Dynojet in Buffalo Grove, IL was 410 whp and 325 wtq @ 10 psi)
Last edited by G60MM; 02-15-2022 at 10:34 AM.
I was able to hit 461 whp on a Dyno-Comp. This is an Active S/C kit, stage 2.
- Aeromotive 380 fuel pump
-Cut ring headgasket
-ARP head bolts
-Bosch 60lbs fuel injecttors
-C38-81 with 75mm pulley (13-14 psi)
-Active intercooler
-Porsche big MAF (3.5"?)
-Schrick Cams 264
-Turner shorty headers
-Active mid exhaust section
-Active rear exhaust section
-Stewart high flow water pump
-S54 full aluminum radiator.
-Stock computer
-Clutch master stage 3 (Not street friendly. I don't like it)
-UUC under drive pulleys (WP & PS)
-Tuned by Frank Smith
I installed the C38-112R with a 85 mm pulley and only got 6-7 PSI of boost. I bought a 75 mm pulley that hopefully will get install this weekend. I went with a full 3" exhaust too.
Here is a bad picture of the car.
E36 1.JPG
Last edited by G60MM; 05-02-2022 at 12:48 PM.
What was the torque on the 461 rwhp run in the Dynocom?
Any Dynojet results? Dynocom is about 10% higher horsepower and 20% higher torque according to one review I read from someone who tested the same car on various dynos years ago. It’s still good for your before and after comparison obviously but probably not good for comparing to results from the much more common Dynojet.
You should be capable for well into the 500's with that blower. With the C38-92 if I went with an 80mm pulley, and tuned for meth, I would be over 500 whp (would require pistons/rods and lower compression). I know AA had to do some custom 3.5" plumbing because of the larger
exit. With a 90mm pulley on my C38-92 we got 10 psi, and with an 85mm pulley we got 13 psi. I'm surprised you weren't able to get more boost...maybe it's geared differently?
MODS: AA SC'D Rotrex C38-92 Stage 2 (60# injectors)==M50 Manifold==Snow Performance Stage 2.5 Meth Kit==Schrick 264/256 Cams==AA Ceramic Coated Headers==AA Trackpipe==Eisenmann Race 2x76==Clutch Master FX250 Clutch==Euro Oil Cooler==MANN Provent 200 Crankcase Catch Can==AA DSB== X-Brace==ZKW 6000K HID FX-R retrofit with Orion V2 L.E.D. Angel Eyes==Euro clear signals and tail lights==M-Tech Pedals and E-Brake==BBS RGR Diamond Black 17x8; 17x9 staggered==Leather Z Gauge Kit (oil temp, oil press, voltage)==Rally Road Guage Pod (steering wheel mounted with AEM AFR guage and Prosport boost gauge)==Cut-ring head gasket==Head refresh done by Autohead Performance==KW V2 Coilover Kit
Current with 85mm pulley and meth: 450 whp 365 wtq @ 13 psi on a Dynojet at Performance Eurowerks in Buffalo Grove, IL.
Previous: AA Mustang Dyno Tuned in Miami, FL @ 10 psi on 93 pump made 392whp 325wtq (Performance Eurowerks Dynojet in Buffalo Grove, IL was 410 whp and 325 wtq @ 10 psi)
Dynocomp and Mustang dyno's read a little less than Dyno yet. This one that I use is spot on. I have GTS2 car that can't be over X amount of HP and when we get randomly flagged for Dyno check, it's always around 2 to 3 % lower. I don't remember the Torque #. I think it was around 400 WTQ.
400 lbs rwtq is way too high from the centrifugal making 450 rwhp. Turbo can do that or better but not a centrifugal due to the exponential boost curve (related to engine/blower rpm).
You would have to be making 500 rwhp in order to have 400 lbs rwtq, but made only 460 rwhp, which should give about 360 lbs rwtq. But the Dynocom is good for comparing your before and after gains from changing superchargers (and, I assume, tunes). It just isn’t reliable for comparing to the more common results from Dynojets.
'98 RMS stage 2+++++(491whp/390tq VAC cams, CES Cutring-9:1, Built blower, Meth etc)
'09 Saab 9-5 Combi 5mt 1 of 1(Built Motor, Brembos, LSD, the works!)
'22 Cadillac CT4-V BlackWing 6mt
'22 Cadillac CT4 2.0T Sport AWD (wife's)
update. I removed the 85mm pulley and installed a 75mm pulley. The bad news is that, even with the 75mm pulley, the SC is only making like 9.5 to 10.5 psi of boost. I took it to the Dyno and we had wheel spin at 5,000 RPM. We tried everything and got it better but, still spinning at 6,400. We hit 413whp and 385 WTQ at 6,400 RPM.
Any of you know if I can fit a bigger crank pulley on the S50? or any other solution to bump the boost? I'm looking for 13 to 14 psi of boost.
E36 Dyno.JPG
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