I was wondering what the power difference is between the 3.5 and 3.4 is? I'm considering getting a 3.4 pulley now.

Go 3.4, i assume it depend how much KR* you will get with the 3.4.

A 3.4 should give +-25hp. its 0.4 difference from stock.

so 15hp seem realistic for a 3.5.

Just make sure you have the basic supporting mods.edit: you already have them except FWI.

However...I run a 3.4 with a gutted air box..and things are good when it'* cool out. Haven't tested my gutted box with warm weather yet.

Didnt you just sell your puller EXPIR
Mike are you saying from 3.4 to 3.5 is 10 HP

Yup, I did, but I got the modular pulley system. I'm having second thoughts about not getting the 3.4. If I do get the 3.4, or smaller, it will take less than 5 minutes to change. I can't see spending $200 for an FWI, when I can spend $60 for a smaller pulley and get more hp gain. It all started when I bought the Intense PCM because I wanted a little more pick up and now I've been bitten by the bug and can't stop. I just ordered an AeroForce scan gauge too.

A 3.5 pulley is going to give a larger gain than a 3.4 if you are stock because you will see a lot less KR.

yes, it all depend on your setup and how your car will react to the pulley, this is where a scan is useful.

Last summer i was only getting 2-3* KR with similar mods you have and my car felt strong even on hot summer days.
Billboost run the 3.4 without problem, you should be ok too, but if you have the opportunity to get it scanned, go for it.

While you can run the pulley with no apparant problems, you would still make more power with a 3.5 and no KR. If you were to get 5* of KR with a 3.4 pulley, then thats 10-15hp you just lost due to the reduced timing from that. Going from a 3.5 to a 3.4 pulley is only going to give you ~10hp if everything else is the same (if even that much power), so you are actually hurting yourself and your engine. We ran our '00 SSEi for 2 years and over 50k miles with just a 3.4 and had no problems, but AFTER we did mods to it and scanned it it was getting 7-9* of KR depending on weather conditions and whatnot. It took a DHP and 1.9 rockers to kill off all the KR. With a 3.5 pulley the car would've been quicker all along. And yes, even though the car was suffering with large amounts of KR for a lot of miles, it still runs strong even with 165k+ miles on it, but it would've been quicker with a bigger pulley.

I just recommend the 3.5 pulley because for someone not getting serious they will get a nice gain and they won't have to worry about KR and trying to kill it and whatnot. Then if they decide to get more serious later it doesn't really take that long to change a pulley and they can go with something smaller. But thats just my opinion. We all know he'll get KR with a 3.4 so why recommend it? He has a 3.5 now and isn't having problems with it so no reason to change.

Basically the only thing that he should do is scan the car for KR. See what it is getting now and go from there. When the KR gets down to 0 then maybe drop to a 3.4 and get rid of the KR with that pulley and then move down again. My guess is he'll need either rockers or exhaust work, if not both, to be able to run a 3.4 with no KR. But that is just a guess.

Shawn

Shawn.. I have been running a 3.4 with gutted airbox and not had KR issues. Recently I added ported exhaust manifolds and lost almost all of the KR at shift points. Rogue mentioned this KR is caused by boost dumping for the shift and is normal. The manifolds did help with the 1-2 degrees of KR at WOT that I did have.

The only unknown is that I bought the 3.4 at the end of October and have not scanned it above 80 F degrees.

Thats why i went with the 3.5. I don't want to kill the engine. I guess I'll stick with the 3.5.