Press-on SC pulley, or MPS?

From: https://rivperformance.editboard.com/Other-Stuff-c3/Parts-Wanted-f23/Anyone-in-the-Minnesota-AREA-t197.htm

Travis, curious if you bought a press-on 3.4, or went with an MPS kit?

im getting the press on pulley LOL not enough $$$ for the MPS kit hahha

Travis, in that case you may want to consider investing in a puller. If you rent, then send it back, THEN find you have significant KR issues, you're going to have to track down a tool again if you want to put the 3.8 pulley back on. An MPS kit is cheaper though.

what do u mean by the MPS kit being cheaper do u think i should go to pontiac and see if i can quick borrow their pulley puller and then wait to buy the MPS kit and then get the Hub, 3.4 inch and a 3.25 inch pulley!!!

I mean it's cheaper to buy an MPS kit and rent or borrow a puller, than to buy press on pullies and buy a puller. I think.

If you buy a modular system, you only need to use the puller the first time you do a swap. Once you have the hub on the SC shaft, pulley swapping is just a matter of taking the belt off the pulley, removing some screws, and swapping a different pulley back on, and putting the belt back on.

If you think you can get by with just putting on a 3.4 press on pulley and NEVER have a reason to swap again, then by all means do so. BUT, many guys will tell you they don't run their 3.4 in the winter.

1998 Riv wrote:

I mean it's cheaper to buy an MPS kit and rent or borrow a puller, than to buy press on pullies and buy a puller. I think.

If you buy a modular system, you only need to use the puller the first time you do a swap. Once you have the hub on the SC shaft, pulley swapping is just a matter of taking the belt off the pulley, removing some screws, and swapping a different pulley back on, and putting the belt back on.

If you think you can get by with just putting on a 3.4 press on pulley and NEVER have a reason to swap again, then by all means do so. BUT, many guys will tell you they don't run their 3.4 in the winter.

whats wrong with running the 3.4 inch pulley in the winter??

more KR

If you aren't changing to larger rockers or a cam, don't bother with the 3.4. You'll get too much KR to reap the performance gains of the extra air it can push. 3.5 is the smallest size to go on a stock valvetrain. There are some who disagree, but I've scanned enough 3.4 cars (including my own) to form a pretty solid opinion. Another reason MPS is the way to go. Start with a 3.5 and if you do some other mods you can easily change to the 3.4. If you haven't installed the 3.4 yet it's not too late to change your mind.

Travis, heed Derek's advice, he knows what he's talking about.

Cold winter air is much denser than other times of the year. Denser air means the engine needs more fuel added to the mix to keep the A/F ratio in spec. Your PCM won't be able to add enough fuel, and will instead retard your timing (KR) to prevent knock, which is caused by the lean conditions created by the very cold air.

I agree that the 3.4" is generally not a good idea without rockers, but with proper tuning and supporting mods you can run a 3.4" with minimal KR. It's not easy to do, but possible if you know how to tune. The only reason I say this is, the Riviera's exhaust is less restrictive than on a GS or GTP, so that helps us a bit.

Still, get the 3.5" or 3.6" until you have a scanner at minimum. If you don't have a way to see KR, you won't know if there's a problem. Your engine might not run right, the car won't be any faster than it would with a 3.5", and you'll be wondering why.

ok i may get a reprogrammed PCM and i do have a pretty open exahaust considering i dont have any mufflers and so will i be able to run a 3.4 with a
-reprogrammed PCM from 3800performance.com
-pretty open exhaust
-FWI
-and autolite 104's

A reprogrammed PCM from 3800 is not the same as a tune. The way they set the parameters is a guess at best. They don't know your car, your mods, or your level of KR. Without true tuning cabability, you're going to get what you get.

If you haven't yet, read though this: https://rivperformance.editboard.com/Series-II-3800-Supercharged-c2/Series-II-FAQ-f19/Will-swapping-the-SC-pulley-make-a-difference-t32.htm

where can i get a thrasher MPS. i went to zzp and 3800performance and cant find it! i see individual thrasher pulleys but not the MPS

is there any MPS that anyone thinks is better?

Intense has a nice system...

I just bought a 3.5" MPS from intense the other day. Should be here soon. I got the 3 days shipping cost me $113

ive got the thrasher. I would recommend another brand though. Thrasher only makes pullies in 3.4 - 3.25 - 3.0 - 2.85

thats it. Other brands have sizes by the 1/10th inch.


BTW, I had to get mine on ebay. thrasher sells them there now.

ok. you have inspired me to go with an intense system. where do i get it?

http://www.intense-racing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=IMH-090&Category_Code=BE

When possible, I have almost exclusively used INTENSE parts to mod my car. Great product/service. A bonus is their MPS pulleys are interchangeable with ZZP's. This is a great reason to buy it, trust me.

just ordered it from intense for $111 shipped

What size did you get?

3.5" im gonna rent the tool from 3800performance unless you know of a less expensive way

something pretty funny now, before learning what i learned from you guys, i was going to get a 3.2" based off of what the vendors said. thanks!

I don't understand why a vendor would do that. It's not like they'll profit any more from selling 3.2" pulleys vs. 3.5". Incredibly incorrect and dangerous recommendation. Stay away from any vendor telling you to do a 3.2" right away.

turtleman wrote:

just ordered it from intense for $111 shipped

Congrats! Can't wait to get mine in and get it installed too.

I just got the pulley
waiting for puller