Pully Question
Retired Senior Admin
Expert Gearhead
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin
You scanning your car for KR Knock Retard? If your running with no other mods and a pulley that small you run a huge risk of chipping a piston. Also, for every degree of KR you have you loose about 5hp. With out know more about your car other then what you said, I would guess your getting 8+ degrees of KR and loosing a good 40hp. A stock engine with a 3.5" pulley and a light tune will get more HP then a stock engine with a 3.25" pulley
Retired Senior Admin
Expert Gearhead
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin
As I said in our PM, you need a scan gauge before you do anything else. I really don't want to see you blow the engine. Trust us on this. You will get more power with a larger pulley and no KR. I'm willing to bet money on the fact that you are loosing 40 or 50 hp right now.
With a ported SC, high lift rockers, a good set of headers, a free flow cat, and a good intake. Not to mention a good tune on the PCM you should be able to get to a 3.3", perhaps even your 3.25" But you MUST scan for KR.
With a ported SC, high lift rockers, a good set of headers, a free flow cat, and a good intake. Not to mention a good tune on the PCM you should be able to get to a 3.3", perhaps even your 3.25" But you MUST scan for KR.
DINOSAURUS BOOSTUS
Expert Gearhead
Joined: Mar 2005
Posts: 41,391
Likes: 30
From: Enfield, CT
Rockers, ported charger and some type of exhaust mods. 3.2 is possible, however if you scan and look at timing there is a good chance you will note that your timing is much lower than it should be. I once has the go as small as you can pulley misconception. Through good info etc friends told me I was running on the low octane tables which is what the pcm reverts to when you have enough constant knock.
As you can assume low octane tables mean less timing, less power, less fuel mileage. Oddly enough going to a 3.4 or 3.5 if you have low timing or knock could gain you more timing, more power and better mileage while using less power from the motor to turn the bigger pulley.
Sounds like you are willing to listen from those that blew up motors before you.
As you can assume low octane tables mean less timing, less power, less fuel mileage. Oddly enough going to a 3.4 or 3.5 if you have low timing or knock could gain you more timing, more power and better mileage while using less power from the motor to turn the bigger pulley.
Sounds like you are willing to listen from those that blew up motors before you.
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