dkorinko Posted March 5, 2006 Report Share Posted March 5, 2006 I was just wondering what to expect if I were to change to a 3.25" pulley from the stock one that I have on the supercharger now. I was curious to see if anyone would happen to know the horsepower gains, or much more boost it actually gives you. The only other mod on the car is a cold air intake. Thanks guys. Dane Link to comment Share on other sites More sharing options...
badassoldspower Posted March 5, 2006 Report Share Posted March 5, 2006 Taken from http://www.zzperformance.com For every person the SC pulley swap should be the first thing considered. It offers the largest HP/dollar value of any mod. You will need a special tool to do the install which can be bought or rented. Install time is about 1 hour. If this is the only mod you plan on doing then the 3.5†pulley should be used. The stock belt can usually be used but we recommend the 4060660 belt or our oversized tensioner pulley. The 3.5†pulley swap will give you ~20 additional HP. If you plan on doing other modifications as well then the 3.4†pulley is a better choice. It requires a smaller belt or an oversized tensioner pulley. The 3.4 will give ~25 additional HP. Supporting mods include colder Tstat, stage 1 throttle body, colder spark plugs, cold air intake, TB spacer and any form of exhaust modifications. We recommend at minimum doing the Ubend delete. Available octane plays a part as well. If you live in a state with only 91 octane available you will need to do additional mods to run a 3.4†pulley without KR. You might want to consider the 3.5. If you live in Indiana or parts of the country with 94 or 95 octane available, it will be very easy to run the smaller pulley w/o KR. Keep in mind that a larger pulley with no KR will make more HP than a smaller with less timing (more KR). If you plan on continuing to mod your 3800 in the future you should buy a modular pulley system. The assembly is lighter than a press on but more importantly, it will make future pulley swaps very easy without needing to use the puller tool again. Then as you mod your car, you can buy smaller pulleys. This will allow you to run one size pulley for the street and one for the track or when using race gas. After or along with the pulley you should run a colder Thermostat and colder spark plugs. The 160 is the best choice but doesn't work very well in winter operation. You can switch back to stock for winter use or buy the 180 and use it year round. For a colder spark plug we recommend the NGK TR6 or TR6ix. These plugs will help to lower KR. New plugs will also increase the performance and gas mileage of a car with used plugs. Many people run TR55's but we have found no ill effects of running TR6's and they work better for getting rid of KR. If you have a 97 or 98 then a CAI is a very good choice as your next mod. If you have a 99 or newer your air-box is a little better and you can postpone doing a cold air intake. The Wizaired box will give excellent gains and help reduce the KR that you will most likely be getting from running the smaller pulley. Exhaust should be considered at this point. The U-bend should be your first part of the exhaust to upgrade followed by the resonator, then down-pipe. After that your manifolds are the most restrictive, then your piping to the Y section and finally your pipes to the stock mufflers. The factory mufflers are not restrictive and should be changed based on looks/weight/sound before all else. Once you're making over 300WHP then we can talk about the performance aspect of mufflers. The U-bend and/or resonator should cost $50-100 to be replaced by a local exhaust shop. You'll want to pick up an O2 simulator if eliminating your rear O2 sensor. And yes, this stuff is all emissions legal as you are not messing with the operation of the cat. Exhaust work is an excellent way to get rid of KR when running smaller pulleys. Easy mods from here include a water pump under-drive pulley, and a throttle body spacer. The Spacer will help get rid of KR, the WP UD pulley will free up a few top end HP. Both are inexpensive ways to continue the pursuit of HP. The DHP PCM is an excellent mod a this point. It will help lower KR, and make driving the car a much more pleasurable experience. It increases HP, changes shift points as well as fueling, makes the car shift harder under Perf shift mode, takes away your top speed limiter, raises your rev limiter and has a few other tweaks. It will lower your gas mileage slightly and increase the chance of tranny failure (due to firmer shifts) but at your HP level now you shouldn't have to worry about the transmission yet. At some point above you are going to want to consider Poly Motor Mounts and a shift kit. The shift kit in combination with the PCM can break hard parts in the transmission so that is something to be aware of especially if you have heavier rims/tires/brake rotors over stock. You are now done with the easy stuff that most people do. From here you need to decide how far you're going to take your car. This will help you make the decision between high ratio rockers and an after-market camshaft. If you plan on being faster than mid 13's or make more than 280 crank HP you're going to need to do one of 3 mods. Rockers, intercooler, or Cam. Rockers add ~25HP, increase gas mileage, do not change reliability of the car, cannot be seen by the dealer, are relatively easy to install yourself and will support low 13's without an intercooler. They help the engine flow better, lowering KR and allowing a drop in pulley size by about .1â€Â. Combined with an intercooler many users have taken a 3800 with stock camshaft, rockers and an intercooler deep into the 12's with close to 300WHP. Bang for the buck rockers are an awesome mod. Link to comment Share on other sites More sharing options...
jeremy Posted March 5, 2006 Report Share Posted March 5, 2006 http://www.w-body.com/forum/viewtopic.php?t=39164 Link to comment Share on other sites More sharing options...
sl3196 Posted March 5, 2006 Report Share Posted March 5, 2006 Don't even think about switching to a 3.25 pulley on a near stock car. Read what badassoldspower copied from zzp. Link to comment Share on other sites More sharing options...
dbtk2 Posted March 6, 2006 Report Share Posted March 6, 2006 As was already said, a 3.25" pulley is a bad idea. Get a modular system and go with a 3.4 to start with. Before you drop to something smaller you'll want an intake, some exhaust work (downpipe & u-bend delete), a PCM, and probably 1.9 rockers or a cam. 3.25" is a bad idea and your car will probably slow down. I remember a few years ago when my dad was running a 3.25" pulley. He was getting absolutely no KR at all whatsoever. The car was decently modded but he had a thrasher pulley system so the next size pulley was a 3.0, he couldn't go to like a 3.1 or 3.2. He put a 3.0 pulley on it and the car was a huge turd. It was getting ~9* of KR and it was WAY slower than it was with the 3.25" pulley. Shawn Link to comment Share on other sites More sharing options...
dkorinko Posted March 6, 2006 Author Report Share Posted March 6, 2006 How would a 3.25" actually slow the car down though? Going from a stock pulley I dont see how it could....???? You guys have to help me with this shit lol, I could pretty much do anything on my 89 TGP but with this 97 GTP I am pretty confused when it comes to a lot of stuff.... Link to comment Share on other sites More sharing options...
badassoldspower Posted March 6, 2006 Report Share Posted March 6, 2006 Ok the reason you cant just slap on a 3.25 pulley is because the car will obtain too much boost, and you will get KR, or knock retard which means that the knock sensor on you engine is hearing "knock" so it compensates by taking away timing, or retarding the car's timing. So when your stock pulley is on, the car is able to have plenty of advance, because there is no knock. So the reason it would slow down is simply put because the computer is saving your motor from detonation, by retarding the timing. And by adding intake/exhaust, enriches the air/fuel ratio, you help the engine breath more, which removes some KR (knock retard) I think that is accurate, that is my understanding of situation. Link to comment Share on other sites More sharing options...
dkorinko Posted March 6, 2006 Author Report Share Posted March 6, 2006 Ok now that makes sense thank you, well sadly enough i ordered the 3.25" pulley before getting much of this info BUT, I do already have a cold air intake, and the same time that the pulley is being installed, NGK race plugs, a 160 degree thermostat, MSD plug wires, gatorback belt, and a free flowing exhaust system is also being installed, so hopefully i will be ok? I will also continually be running 100 octane fuel in the car, I should be ok, right????? Link to comment Share on other sites More sharing options...
badassoldspower Posted March 6, 2006 Report Share Posted March 6, 2006 with that setup with that kind of fuel and intake/exhaust, im gonna say you SHOULD be ok. Are you getting NGK tr6 plugs?. im gonna say yeah you should be ok, but just to be safe, get a DHP powertuner, so you can tune for optimum performance with the 100 octane fuel EDIT: You should go to 1:9 rockers too, that your best bet Link to comment Share on other sites More sharing options...
digitaloutsider Posted March 6, 2006 Report Share Posted March 6, 2006 I think you'll still be seeing KR out the ass, and I'd get the car scanned before I even installed the pulley. Make sure the plugs are AT LEAST 2 ranges colder, or you're risking detonating the engine. A good intake and u-bend/resonator removal IS A MUST. PEM's/headers should seriously be considered. I'll be totally honest with you, I wouldn't install that pulley before I got the car scanned or installed the aformentioned supporting mods. You're asking for trouble. Link to comment Share on other sites More sharing options...
sl3196 Posted March 6, 2006 Report Share Posted March 6, 2006 Send that pulley back and order a 3.4. Link to comment Share on other sites More sharing options...
john99gtp Posted March 7, 2006 Report Share Posted March 7, 2006 Don't even think about switching to a 3.25 pulley on a near stock car. Read what badassoldspower copied from zzp. going to 3.25 with nothing is insane dont even think about doing it even a 3.4 with no mods is cutting it Link to comment Share on other sites More sharing options...
dkorinko Posted March 7, 2006 Author Report Share Posted March 7, 2006 Don't even think about switching to a 3.25 pulley on a near stock car. Read what badassoldspower copied from zzp. going to 3.25 with nothing is insane dont even think about doing it even a 3.4 with no mods is cutting it Did you not see my last post? I already have a cold air intake, and the same time the pulley is being installed, there will also be NGK race plugs, a full exhaust system, MSD plug wires, a 160 thermostat, and the car will be running 100 octane fuel......oh, and the gatorback s/c belt..... Link to comment Share on other sites More sharing options...
jeremy Posted March 7, 2006 Report Share Posted March 7, 2006 Send that pulley back and order a 3.4. take this advice Link to comment Share on other sites More sharing options...
john99gtp Posted March 7, 2006 Report Share Posted March 7, 2006 thats still not nearly enough for a 3.25 IMHO Link to comment Share on other sites More sharing options...
sl3196 Posted March 7, 2006 Report Share Posted March 7, 2006 thats still not nearly enough for a 3.25 IMHO Buy yourself a scanner. Unless you like blowing shit up! Link to comment Share on other sites More sharing options...
White93z34 Posted March 7, 2006 Report Share Posted March 7, 2006 i bet 100octane gas will get REAL expensive REAL quick Link to comment Share on other sites More sharing options...
digitaloutsider Posted March 7, 2006 Report Share Posted March 7, 2006 Don't even think about switching to a 3.25 pulley on a near stock car. Read what badassoldspower copied from zzp. going to 3.25 with nothing is insane dont even think about doing it even a 3.4 with no mods is cutting it Did you not see my last post? I already have a cold air intake, and the same time the pulley is being installed, there will also be NGK race plugs, a full exhaust system, MSD plug wires, a 160 thermostat, and the car will be running 100 octane fuel......oh, and the gatorback s/c belt..... Your point? I'm running nearly all of that minus the plug wires and thermostat (I use 180. 160 is too cold for good gas milage and can cause premature wear of the piston rings. U-bend/res delete, no pems/headers). I would NEVER EVER dream of putting a 3.25 pulley on that car. You're asking for trouble. But hey.. it's your engine and your money. If you want to be replacing it in a couple thousand miles, be my guest. If you don't want to listen to us when we're giving you important advice that's your problem. We're telling you that you don't have enough supporting mods to use the pulley. If you want to disagree with us and run it anyway that's your business; Just don't come back crying to us when you pop a piston. (If by full exhaust you mean PEM's/headers, then you should be able to get away with it. If not, you'll require alcohol injection to run this pulley). Link to comment Share on other sites More sharing options...
loccomoco Posted March 7, 2006 Report Share Posted March 7, 2006 Well if you have full exhaust, an intake, diffrent plugs (2 degrees colder), and thermostat. You should be able to run it. PCM is one of the supporting mods as well. Don't go throwing on a pulley that small until you have everything done. It would be asinine to do so. Also, if you plan on running your car with 100 octane, plan on replacing your front 02 sensor because that will be gone in a few miles. Go ahead and get some rockers while your at it. Seriously, this advice will help you. BTW: SCAN YOUR CAR Link to comment Share on other sites More sharing options...
dkorinko Posted March 7, 2006 Author Report Share Posted March 7, 2006 Well if you have full exhaust, an intake, diffrent plugs (2 degrees colder), and thermostat. You should be able to run it. PCM is one of the supporting mods as well. Don't go throwing on a pulley that small until you have everything done. It would be asinine to do so. Also, if you plan on running your car with 100 octane, plan on replacing your front 02 sensor because that will be gone in a few miles. Go ahead and get some rockers while your at it. Seriously, this advice will help you. BTW: SCAN YOUR CAR This is the reason why I am questioning you guys, I trust all of you equally but as you can see, some of you say I will be just fine while others seem to think my motor will be shot if i do this???? Link to comment Share on other sites More sharing options...
dkorinko Posted March 7, 2006 Author Report Share Posted March 7, 2006 i bet 100octane gas will get REAL expensive REAL quick I can get it for $2.00 per gallon, which here in AZ where premium runs 2.57, it doesnt sound like such a bad deal Link to comment Share on other sites More sharing options...
sl3196 Posted March 7, 2006 Report Share Posted March 7, 2006 I don't see any of us here saying you'll be just fine. Link to comment Share on other sites More sharing options...
99RegalGS Posted March 7, 2006 Report Share Posted March 7, 2006 My friend put a 3.25" pulley on his car about a year ago. At the time he had 3" exhaust from the cat back (including the ubend removal) and a gutted airbox. We got it scanned and he was getting 6-7* of KR. Not very good. A few weeks later he got a 3" DP high flow cat and made a fenderwell intake. Scanned it again. This time he got 4* of KR. Lower, but still not that great. He now has a DHP PCM. He doesn't have access to a scanner at the moment so we're unsure what his current KR is. But I would guess 0-2* of KR still... Personally I would hold off on the pulley untill you get some exhaust done and a PCM. Then you may be fine with a 3.25" pulley or you still may be getting a bunch of KR yet. every car is different. On my car I'm going to wait on the pulley. I see 11psi on cold nights now. And my only mod is a gutted airbox with a K&N. So I know I'm boost stacking, aka too much exhaust restriction. So exhaust is going to be my next on my list of mods even though a pulley is temping. I mean 20+hp for $70, pretty good huh? But I want to make sure my car is able to handle the extra air and heat. You guys have to help me with this shit lol, I could pretty much do anything on my 89 TGP but with this 97 GTP I am pretty confused when it comes to a lot of stuff.... Do you want to know why it's different? Mainly it's because your old TGP was intercooled and the turbo in the TGP was more efficent that the eaton roots blower on your GTP. Sooo you were able to crank up the boost more w/o the heat gains like GTP's have. Link to comment Share on other sites More sharing options...
dkorinko Posted March 7, 2006 Author Report Share Posted March 7, 2006 Well I guess we will have to see what happens....the pulley and belt have already been shipped, and I think the thermostat and plugs get sent out tomorrow.... So the stuff should be here within a few days... I will let you guys know what happens. Link to comment Share on other sites More sharing options...
loccomoco Posted March 7, 2006 Report Share Posted March 7, 2006 Go ahead and make a new post called "Popped a piston" Hopefully you will be extremely easy on the gas until you get some of the supporting mods on. Link to comment Share on other sites More sharing options...
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