superchargerrebuilds.com review. Stay away.

[pbonsalb]

Problem with changing crank pulley is overdriving the other accessories. Maybe you could get underdrive pulleys made for them but I am not sure if there is space to fit a large enough underdrive water pump pulley. Maybe you could fit an extra tensioner or idler to improve blower belt wrap, but I don’t know the AA SC well enough to know whether there is space. Can the pulley be machined or refinished for extra grip?

Even the Dinan/RMS systems with extended crank pulley and dedicated blower drive have trouble with belt slip when trying to spin their Vortech blowers fast enough to make 500 rwhp (and the 400 lbs rwtq you get from a centrifugal on one of these motors if making 500 rwhp). Has to be even more challenging with twice as long a belt and fewer ribs and less tension.

[G60MM]

Problem with changing crank pulley is overdriving the other accessories. Maybe you could get underdrive pulleys made for them but I am not sure if there is space to fit a large enough underdrive water pump pulley. Maybe you could fit an extra tensioner or idler to improve blower belt wrap, but I don’t know the AA SC well enough to know whether there is space. Can the pulley be machined or refinished for extra grip?

Even the Dinan/RMS systems with extended crank pulley and dedicated blower drive have trouble with belt slip when trying to spin their Vortech blowers fast enough to make 500 rwhp (and the 400 lbs rwtq you get from a centrifugal on one of these motors if making 500 rwhp). Has to be even more challenging with twice as long a belt and fewer ribs and less tension.

Maybe I was not very clear. What was slipping was the rear tires not the belt. I have 255 on the rear but I was told that me tires were to soft to grip on the Dyno roller channels.

[pbonsalb]

Lower the tire pressure and strap it down better. Have people sit in the trunk if still needed. Plenty of us with more power and torque have successfully run on dynos, sometimes needing one or more of the things I described to help. The gradual onset of torque with a centrifugal should not pose nearly the problems of a hard hitting turbo, though.

[G60MM]

We tried all that with no luck.

[Colby Colbs]

We tried all that with no luck.

3M Spray Adhesive. Roll the car on the dyno and spray an even coating until it gets tacky. Makes a huge difference on worn roller dynos.

[abradic]

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.

Attachment 703113

I would have think a 75mm pulley will get you 13 psi at redline. Is your rev limiter set to 7200? If you can resolve the issues with slipping on the dyno, you should be around 12-13 psi by redline.

[G60MM]

I would have think a 75mm pulley will get you 13 psi at redline. Is your rev limiter set to 7200? If you can resolve the issues with slipping on the dyno, you should be around 12-13 psi by redline.

The Rotrex C38R-112 turn slower than the other C38. I think that is why I'm not able to hit 13 psi and the rev. limiter is set to 7,200 RPM.

- - - Updated - - -

3M Spray Adhesive. Roll the car on the dyno and spray an even coating until it gets tacky. Makes a huge difference on worn roller dynos.

We did not tried that. I'll bring a can next time. Thanks.

[abradic]

The Rotrex C38R-112 turn slower than the other C38. I think that is why I'm not able to hit 13 psi and the rev. limiter is set to 7,200 RPM.

I know it turns slower...on my 85mm pulley I'm hitting 13 psi, so with a 75mm pulley you should be similar. If you can resolve the dyno slippage issues, you should get very close to 12 psi by 7200 rpm. You'll pull another 2 psi those last 800 rpms, maybe even 3.

[damnboy37]

That’s some nice power from the c38, can’t wait to see the results.

I’m only making 316/269 on my Dinan s3 kit (vortech v2 si, 3.15in or 80mm pulley and upgraded impeller from 928), I don’t have any other mods. I really need a boost gauge and a tune, but don’t know anyone in SE Wisco that knows about boosted s52s.

[pbonsalb]

310/270 is not bad for a low boost non intercooled centrifugal. If you run 93, a modern tune might get you a little more power but not significant gains. You would need an intercooler like the RMS, bigger crank pulley, bigger injectors, pump, higher flow hfm and tune to add significant power — the 375-425 rwhp range depending on supporting mods and boost. I think you are smart to look for someone who knows supercharged E36 well if you do not, but I am in NH and can’t help you in WI. If you can’t find the support you need, I would leave well enough alone rather than risk spending a bunch of money and either not being satisfied or worse, damaging your motor. Maybe buy an E92 M3 instead — they are a lot of fun (I had an E90 M3 for 10 years).

[abradic]

That’s some nice power from the c38, can’t wait to see the results.

I’m only making 316/269 on my Dinan s3 kit (vortech v2 si, 3.15in or 80mm pulley and upgraded impeller from 928), I don’t have any other mods. I really need a boost gauge and a tune, but don’t know anyone in SE Wisco that knows about boosted s52s.

Have you thought about coming to the Chicagoland area? Performance Eurowerks may be able to help you, they prep many BMW track cars. Fluid Motor Union does tons of bimmers, as well as various others.

[damnboy37]

I was looking for a e90 before I found my f87 a few years ago, I still want to get one someday

[damnboy37]

Have you thought about coming to the Chicagoland area? Performance Eurowerks may be able to help you, they prep many BMW track cars. Fluid Motor Union does tons of bimmers, as well as various others.

I went to Fall Line back in 2013 with no luck, I was thinking about taking it to CES in NC back in 2018 before I got my m2, it’s been on the back burner ever since.

[pbonsalb]

CES is good and would be at the top of my list, but it’s a drive from WI to NC. Ask Jamesons viggen — he took his car there from halfway across the country and his great results after having been disappointed dealing with another tuner. Maybe there is some place experienced with these cars that is closer.

[abradic]

I went to Fall Line back in 2013 with no luck, I was thinking about taking it to CES in NC back in 2018 before I got my m2, it’s been on the back burner ever since.

I contacted Fall Line when I wanted to add a meth kit and go with my 85mm pulley, as well as swap in my current clutch. They never called me back, and even the guy on the phone didn't really sound interested on my initial call. Performance Eurowerks was pretty helpful though, but if you are looking for a big project CES is as good as it gets. When I did my initial tune I sent my car down to AA for a dyno tune. It was worth shipping the car there, and then drove it back. They also upgraded my head gasket to a cutring, and I spoke with John at CES to order it. He seems as legit as all the posts on here suggest and was very friendly. If I were to do a big upgrade (pistons/rods along with 80mm pulley) I would most likely send it to CES and have Nick G dyno tune it. I believe the only way Nick G. will tune it is if John does the hardware...I could be wrong though. Just for the Nick G. tune alone it would be worth sending it to CES.

[Jamesons Viggen]

Put 1000 miles on my car this weekend. Also had my buddy who really knows how to drive give our friends some runs in it. He came back saying it's night and day after being tuned by Nick and gone over by CES. Totally worth the drive.

[G60MM]

Hey guys, does any of you know if it's possible to add a bigger crank pulley on a S50? I have a spare crank pulley from an S52 and both look like the same size.

[pbonsalb]

How much bigger can you go without over driving the accessories? You could compensate with underdrive pulleys for the accessories but space is limited for the water pump pulley. Not sure about AC.

With a Dinan or RMS supercharger, there is a dedicated blower drive and you can fit larger pulleys to drive the blower. These require a thinner or smaller electric fan. I never went over 6.00” but some have.

[G60MM]

How much bigger can you go without over driving the accessories? You could compensate with underdrive pulleys for the accessories but space is limited for the water pump pulley. Not sure about AC.

With a Dinan or RMS supercharger, there is a dedicated blower drive and you can fit larger pulleys to drive the blower. These require a thinner or smaller electric fan. I never went over 6.00” but some have.

I have under drive pulleys on the water pump and power steering. I don't think I have one on the alternator. It also have an Spal electric fan. My problem might be the radiator. I installed an S54 M3 aluminum radiator that is like twice the size of the stock one. I have a stock size but in aluminum somewhere in the attic.

My tuner told me that every 5mm up in size = 2 PSI of boost. I will call RMS and see what are my options. Thanks for the information PBONSALB.

[pbonsalb]

I ran a Z3M S54 radiator with Spal 16” 1600 cfm electric puller fan with an RMS Vortech kit and 6.00” extended crank pulley for the blower drive. The 5mm smaller equals 2 psi seems like it is for using a smaller pulley on the blower rather than a larger pulley on the crank but math is not my strong suit so I would have to work it out in paper to test my guess.

You can cut the threads off the WP fan stud if you need clearance for the fan motor or offset the fan. 1600 cfm is not much for a higher boost supercharged car, so you will need a good pusher fan on the other side. Not having AC would help but I kept AC. Some have gone down to a 14” fan but then it covers even less of the radiator core. A 16” covers less than half and there is no room for a shroud to help pull air from the whole core.

If you have cooling problems, I think a Stewart pump with a regular drive as opposed to underdrive pulley is best. No issues with overdriving if you have the Dinan/RMS dedicated blower drive Vortech system. It could be a problem with a VFE or AA or old ESS system that runs the blower off the accessory drive.

[G60MM]

I talked to RMS and they said to get a custom bracket to move the S/C forward and custom pulleys. He said that it will be close to $3K at the end or sell my kit and buy one of his S/C kits.

[pbonsalb]

Ok. You don’t have the Dinan/RMS kit. That was not clear. You would need a lot of hardware to start over. It’s not worthwhile unless you are hardcore into superchargers. Just go turbo and make way more power under the curve. Plus you may need a new tune and fuel injection hardware if significantly increasing power. Plus an intercooled assuming you have a VFE or old ESS kit. And if it is an old ESS kit, it’s an old Vortech that should at least be rebuilt with a better impeller.

[abradic]

I talked to RMS and they said to get a custom bracket to move the S/C forward and custom pulleys. He said that it will be close to $3K at the end or sell my kit and buy one of his S/C kits.

Please do yourself a huge favor and stop talking to RMS. They ARE NOT the tuner you want to be taking advice from...especially for a Rotrex kit. AA, John at CES who works with Nick G for tuning, Jordan at RK Tunes, all of these are far better options. RMS couldn't tune their own kits, so they definitely aren't a good source for someone else's kit. If you are running their tune now, you need to take it easy with the car until you get a reputable tune. This forum is full of countless threads with RMS issues if you search.

[Jamesons Viggen]

I talked to RMS and they said to get a custom bracket to move the S/C forward and custom pulleys. He said that it will be close to $3K at the end or sell my kit and buy one of his S/C kits.

Please do yourself a huge favor and stop talking to RMS. They ARE NOT the tuner you want to be taking advice from...especially for a Rotrex kit. AA, John at CES who works with Nick G for tuning, Jordan at RK Tunes, all of these are far better options. RMS couldn't tune their own kits, so they definitely aren't a good source for someone else's kit. If you are running their tune now, you need to take it easy with the car until you get a reputable tune. This forum is full of countless threads with RMS issues if you search.

This.

Any question I had for RMS led to a multi-thousand dollar rabbit hole. Dont do it. Far better pathways like the CES/Nick G route which I recently took myself.

[G60MM]

Thanks everybody for the information. I think I found a bigger crank pulley. GDM makes a 1" bigger crank balancer/pulley and I'll go up in size on the S/C pulley to lower the boost to 13-14 psi. I'll report back with my findings.