anyone runnin the 2.5 pulley...wat kinda boost are u seeing...just getting an idea here
you scratch my ride IMA EAT YO CHILDREN
i ran it.... with and with out alcohol injection... did nothing but heat up the engine more than what a 2.6" pulley did.... personaly i would say nothing smaller then a 2.6" should be used... with a 2.5" pulley i belive the supercharger is spining at some where in the high 16,000rpm to low 17,000 rpm range... which is way past the suggested limit... now all this means is slight bit more wear on the supercharger nothing to bad (your s/c'er wont last as long though) BUT! roots superchargers are VERY unstable when spun to far past their limits...
I was getting 9-10psi of boost with the 2.6" pulley and alcohol injection which, is the max this supercharger will give you, any one claiming higher is most likly telling you what they saw on boost spikes which can be a result of it spining to fast... so really its more of a waist of money i personaly think and that is from experience from trying the 2.7" , 2.6" and 2.5" all with and with out alcohol...
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Did you ever have it dynoed with the 2.6 pulley and alky. Just curious what kind of hp numbers that would be. 230WHP??
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
i'm currently running the 2.5" pulley with an M4 alky injection nozzle. Now Josh is right about the s/c being right at its limits with the 2.5" so most will not see much of an improvement over the 2.6" if any, but my s/c is fully internally ported both on the intake side and the tb side. The 2.5" actually dropped my g-tech times from 13.56@106 to 13.44@107 so in my case i think it was worthwhile. Now i just cant wait to start the tune with the HPTuners software which is supposed to be here in the next day or so. Once i ditch this Apexi and fmu i'm sure i'm going to have a much more drivable can street friendly car
"Horsepower is the Ultimate Accessory"
Yea in Jimmys case if you have your supercharger ported then i can see the 2.5" pulley being of more use... that i wont agrue..... im looking to do the same here soon... where did you get yours done jimmy and how much of a improve ment did it feel like it gave you?
Wade Jarvis - nope sorry no dyno numbers... just going by feel on this one and a car(s) i raced with both set ups... didnt change the out come at all i just noticed my engine temp was alot higher....
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
jimmyc99z24 wrote:i'm currently running the 2.5" pulley with an M4 alky injection nozzle. Now Josh is right about the s/c being right at its limits with the 2.5" so most will not see much of an improvement over the 2.6" if any, but my s/c is fully internally ported both on the intake side and the tb side. The 2.5" actually dropped my g-tech times from 13.56@106 to 13.44@107 so in my case i think it was worthwhile. Now i just cant wait to start the tune with the HPTuners software which is supposed to be here in the next day or so. Once i ditch this Apexi and fmu i'm sure i'm going to have a much more drivable can street friendly car
Did u port more then just the intake runners?? did u do it, or did you get a shop to do it? got any pics of the work??
ps..ur car is killer.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
jimmyc99z24 wrote:i'm currently running the 2.5" pulley with an M4 alky injection nozzle. Now Josh is right about the s/c being right at its limits with the 2.5" so most will not see much of an improvement over the 2.6" if any, but my s/c is fully internally ported both on the intake side and the tb side. The 2.5" actually dropped my g-tech times from 13.56@106 to 13.44@107 so in my case i think it was worthwhile. Now i just cant wait to start the tune with the HPTuners software which is supposed to be here in the next day or so. Once i ditch this Apexi and fmu i'm sure i'm going to have a much more drivable can street friendly car
Did u port more then just the intake runners?? did u do it, or did you get a shop to do it? got any pics of the work??
ps..ur car is killer.
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
sorry for the delay on the response, im usually on my own car clubs forums most often, if any of you guys ever wanna check out some pretty nasty cars just take a look www.607motorsports.com
Anyways though, i did the porting myself, i have been doing head porting and polishing for years, before the cavy i was a big v8 guy (mustangs, camaros etc.) I've accumulated all of the necessary tools to do the job right. I ported my intake runners to match my ported head then increased their diameter gradually as they got closer to the s/c opening. All internal opening were smoother and polished and all extra casting was removed. I then ported the TB side of the s/c as much as I could before it got too close to the seal which is there. The overall size now is about 65mm which is also what i had a custom TB made for. Sorry I do not have any pics of this
I am terrible when it comes to documenting work, and as for differences I honestly couldn't tell you that either because I ported and polished the unit before it ever went on the car for the first time, sorry guys. I will tell you in flow bench testing that the ported s/c unit has approx. 12% greater flow than the stock casting. There is room for improvement in there, the casting is pretty thick and the transitions can definately be helped. Hope that helps guys.
"Horsepower is the Ultimate Accessory"
damn jimmy. Wanna do my extra 2k 2.4l head i have?
Nate
Evolution of Cavyboy-->C22t--> C24na--->c24s/c
1995 Cavalier W/2k1 Engine
GM S/C 13.940@99.78pmh w/2.068 60ft
