3.4 or 3.5 Pulley

[3800Charged]

Finally thinking about dropping pulley sizes, might do a 3.5, or should i just do a 3.4?? If i do either do i need to get different size belt? Thanks

[00Beast]

What mods do you have? You'll for sure need a belt with the 3.4, likely with the 3.5.

[3800Charged]

Just got finished doing some work lol
Headers
3" downpipe
3.5" FWIC
160* Stat
Custom HP Tuners Tune
NGK TR6's

[2003 SSEi]

Some things i noticed.

IF you have headers, you cant have a downpipe, it is built into the headers

The 160* thermo is too cold for your car. Remove it for a 180 and have the fans properly set

you will need to get with your tuner, and scan AFTER the pulley is installed to see what kind of Adjustments need to be made.

[MattStrike]

So If you have the same SC belt idler pulleys that I do ('98) you can get away with changing the belt routing and still use the stock belt length down for a 3.4 & 3.2. But you'd need an underdrive water pump pulley (3400 pulley modified or billet aluminum), the belt may rub on the stock WP pulley if you do that (mine did, ran it for 6 months that way with no problems. Fixed it right after I had to do the last rebuild though). I did it to clear the A/C clutch hub on my engine swap, and discovered that it requires a 1" longer belt for the alternate routing. If your idlers are smaller than mine were, it will not take up as much slack.

[3800Charged]

Some things i noticed.

IF you have headers, you cant have a downpipe, it is built into the headers

The 160* thermo is too cold for your car. Remove it for a 180 and have the fans properly set

you will need to get with your tuner, and scan AFTER the pulley is installed to see what kind of Adjustments need to be made.

Actually my headers merge together into a Y and dump into a 3" DP
Proli true about the 160* being to cold, but i only put that in cause its balls hot in FL and I was seeing a lot of knock and didnt have the means to tune it at that time so it will proli be changed out

So If you have the same SC belt idler pulleys that I do ('98) you can get away with changing the belt routing and still use the stock belt length down for a 3.4 & 3.2. But you'd need an underdrive water pump pulley (3400 pulley modified or billet aluminum), the belt may rub on the stock WP pulley if you do that (mine did, ran it for 6 months that way with no problems. Fixed it right after I had to do the last rebuild though). I did it to clear the A/C clutch hub on my engine swap, and discovered that it requires a 1" longer belt for the alternate routing. If your idlers are smaller than mine were, it will not take up as much slack.

Thanks for the info, yea im not sure if my year had the same size pulles as that, maybe somebody will chime in with that info

[2003 SSEi]

If your seeing knock then you need to adjust for that, not throwing in a cooler thermo. The knock sensors dont turn on untill 150* degrees with the stock calibration.

[3800Charged]

yea its been tuned, i have 0 knock at WOT from 0-120, so thats not a concern anymore

[yourgrandma]

All other issues aside, for your climate I would be careful even with a 3.5. Balls hot is pretty hot. Without any other airflow mods I don't know if you can really pull off much of a drop.

Nice thing with an mps is you can swap pulleys all day. I'd start with the 3.5. Scan, tune, assess.

[3800Charged]

All other issues aside, for your climate I would be careful even with a 3.5. Balls hot is pretty hot. Without any other airflow mods I don't know if you can really pull off much of a drop.

Nice thing with an mps is you can swap pulleys all day. I'd start with the 3.5. Scan, tune, assess.

yea pretty much my thought exactly! was leaning towards the 3.5 for the fact that it wasnt a huge step and possibly using the stock belt(still not sure) and my tuner is a close friend of mine so i can adjust on the fly whenever i need! I still need to figure out how to lower my IAT's. theyre pretty hot, i need to find something to either wrap or coat my intake pipe lol

[SSEiFreak]

I myself run a 3.4 pulley but I have a couple more things done and it did require a different belt. I run it with a full headers back exhaust, 180* thermo, copper 104's, custom intake, headers are wrapped, i am running no cat, with a thrush cherry bomb, egr delete, tune by the gtp god in indy and a couple other things. Like yourgrandma said you need to ensure more of an airflow upgrade before dropping to a smaller pulley because it is gonna try to suck more in and you will just be restricted and get no benefit from it.