MrJohnnyLy

Sorry for the noobness guys, but I recently purchased an s2000 with a comptech supercharger installed. The other day it made a rattling sound at idle, so I called Paxton and they said that it wasn't normal and needs to get serviced. I removed the blower and while it was off the car, I measured the size of the pulley and it looks like it's running a stock 5" pulley. Since the supercharger is already off the car, I was considering upgrading to a smaller pulley, like 4.2" or 4". What I'm wondering is: is this safe to run on a stock kitted comptech supercharger system or would Flashpro/AEM EMS be required? Is it possible to tune a S2000 without engine management (I'm not sure if the comptech one that comes with the SC is even considered engine management lol)?

Thanks in advance!

CoolGuy094

No. You can not run a larger pulley (larger than a 7 PSI pulley) and retain the "base kit" rising rate fuel pressure regulator and Comptech ESM. You will need to step up to a tunable engine management (AEM, Haltech, KPro, or Flashpro if you are 06+) as well as larger injectors and likely an aftermarket MAP sensor. You will uninstall the Comptech RRFPR and the Comptech ESM. Additionally you will want to upgrade your clutch to at least an ACT HD pressure plate with the OEM friction disc if you haven't already. It will be about a $2k-$3k investment for parts depending on the deals you can find, plus another $400-$600 in tuning costs depending on what your tuner charges.

I just went through the motions of exactly what you are looking to do over the past few months. Upgraded from the 6-7 PSI Comptech base kit to a 13 PSI setup with Haltech standalone engine management, ID1000's, Hondata MAP sensor, and the SOS clutch kit. Feel free to PM me if you need specific help/questions on anything.

MrJohnnyLy

Thanks for the reply!

My S2000 is a 2003. If I run a 4.6" (Science of speed says it's rated for 7PSI), would I still need to run a tunable engine management system?

http://www.scienceofspeed.com/produc..._1220_pulleys/

starrman

You go past the point and you need to get the stuff... as mentioned above, most important of all...the tune.

CoolGuy094

I don't remember what pulley I had for my Novi 1220, but my boost gauge read 7 PSI at redline. I was able to adjust the RRFPR to keep my AFR's within an acceptable range. However I had the stock exhaust still on the car. Some guys with aftermarket exhausts/cats have had issues with keeping their AFR's in check at 7 PSI. You need a wideband gauge to be sure you aren't running too lean.

Moddiction

If you go any smaller pulley then stock you will need injectors, pump and a full tune. No cheap way around it if you want the engine to last. I have a vortech kit. Even on the stock pulley I was running way too lean. Do it right do it once.