i have a kraftwerks supercharger with 100mm pulley. has anybody tried a smaller pulley 95mm or 90mm? i see that we can buy pulleys from supercharger rebuilds.

 

Im not familiar with Rotrex pulley sizes,
but I have read about guys on here destroying their blowers by using a smaller pulley than the "hi boost" pulley Kraftwerks sells.. exactly how much smaller I don't remember

 

Yeah from what Ive read it doesn't sound like much. Technically the high boost 4" pulley is already over spinning by 5% if I remember correctly. When they say its maxed out of the box, they weren't kidding. Best option I would think, is to replace that blower with the C38 TTS uses in their kits. 500+ capable.

 

There are a few people that are using the 90mm Rotrex/custom pulley and I am sure a few using a Rotrex 95mm. One past owner had over 100K onhis S with a 90 before the charger tore it’s oil seals up. Looking at a 90 here is the bad and the good: People that have stayed near readline for extended periods have lost their charger and it is a f’n mess when they let go. As junk said above, they are already over spun as it is and with a 90 it’s 110.7% overspun at 8300 rpms. The good is lower boost and more overall boost. I have run a 90 and liked it but have returned back to the 100.

J

 

I went with a smaller pulley as well 95mm.. But from what i am piecing together i see that the problem is not the Rotrex; I am no expert just testing and tuning; So what i am doing is replacing the pulleys on drive that have failed for me , that people claimed "caused slipping" on there kits. Im wondering if this is what overheats the Rotrex to eventually fail. I dont know; I cannot fully review as i just changed it a few weeks ago. Its holding fine.. But i have not had a full track day with it; and probably wont till next season bc id like to upgrade other components (oil cooler , injectors , Kpro).

 

if you look under the tech info section on the rotrex web site it shows 120,000 rpm dotted line being the max. i just order the 95mm pulley and relocating a double the size oil cooler (14 row) and have 2 rotrex reservoirs. so fluid heat should not be a issue.

 

Excellent I am ordering mine as well. Please update progress as you go along.. These threads really helped me get started

 

I've been wondering about this for a while, but didn't want to try a 95mm without some research 1st. I also wonder why Kraftwerks wouldn't offer a "Higher" boost kit with the C38/31? Maybe there isn't enough cooling capacity easily accessed on the S2000? It SEEMS like there is plenty of room for additional cooling to be added...

 

Maybe Krafterks wanted to keep the kit reasonably conservative. C38's are fine on the S2000, here in the UK many of us have the TTS kit which uses a C38 with front mount intercooler.

Dan

 

i'm glad to hear someone else with an ap1 using a smaller pulley than 110mm.

what kind of power are you making ScrapDog and SLINKYDOG?