I bought a 3" pulley about 8 years back when I originally started this project and I'm seeing a lot of different responses about what you need to do to the motor to get smaller pulleys to run.
I have a XP Hot Cam, ported heads and intake, roller rockers, 42# injectors.
What do I have to do other than program the computer for it to get the motor to run correctly with the 3" pulley?
You dont have to tune anything, but a 3.0 is pretty aggressive for the novice that isnt going to make sure everything is running correctly. a 3.2 would be a safer bet to start out with and if you get some scan tools and do some research go into the 3.0 and smaller area.
Also, you will want to switch out the roller rockers for stock.
Do you have a scanner? As long as you consistently monitor for KR you should be fine. Get a (MPS)multi pulley system that way you can easily pulley up or down when needed.
Also, An Intercooler, E85 or both would hook your right up.
Do you have a scanner? As long as you consistently monitor for KR you should be fine. Get a (MPS)multi pulley system that way you can easily pulley up or down when needed.
Also, An Intercooler, E85 or both would hook your right up.
Its been more than confirmed that roller rockers suck.
I bought a 3" pulley about 8 years back when I originally started this project and I'm seeing a lot of different responses about what you need to do to the motor to get smaller pulleys to run.
I have a XP Hot Cam, ported heads and intake, roller rockers, 42# injectors.
What do I have to do other than program the computer for it to get the motor to run correctly with the 3" pulley?
Sell 3.0 pulley for an appropriate size pulley to match ur MODs or add appropriate MODs to run the 3.0 pulley.
I wouldn't let people tell you a 3.0 is wrong really... its what ive always ran on typical xp cam setups but its one of those things that if you are not going to pay attention to things I wouldnt risk it.
So if I use a 3.0 I will constantly have to monitor for KR, but you think with a 3.2 I should be safe without constant survalance?
Constantly... no... I mean if it works it works, but I wouldnt really do it without having a wideband around, or a scan gauge just to make sure you dont lean out due to fuel trims, or fuel pressure, or whatever... anything under a 3.2 is where you get into trouble with stuff like maf sensors, injectors, etc as well.
E85 will make things a lot more safe. You could run a 2.8 pulley no problem as long as the injectors can keep up. A few guys made more power with E85 after they removed their intercooler.
Ok so not to hijack this thread, but I'd like some input on my setup as well and don't want to start another thread on the same thing. Just wondering whether you think I may be in the safe zone (if there is one) or if i may need to do some other things. I am thinking on running a 3.25 pulley on my engine which has a vs cam, dbl roller set, stock lifters, 60lb injectors, 125lb springs and retainers, ported intake, ported sc (bottom corners removed), bit of porting done down near the valve seats in the heads, 3" dual exhaust.
Ok so not to hijack this thread, but I'd like some input on my setup as well and don't want to start another thread on the same thing. Just wondering whether you think I may be in the safe zone (if there is one) or if i may need to do some other things. I am thinking on running a 3.25 pulley on my engine which has a vs cam, dbl roller set, stock lifters, 60lb injectors, 125lb springs and retainers, ported intake, ported sc (bottom corners removed), bit of porting done down near the valve seats in the heads, 3" dual exhaust.
What octane gas? That is one of the main determining factors on how low u can go.
No e 85 around here easily accessible. Just high grade fuel at the pumps. So like 91 octane. I suppose I could run an additive if that stuff even really works. troy
[This message has been edited by fieroaddicted (edited 04-18-2014).]
I don't know that I would build the engine to REQUIRE High Quality Gas, not like we can expect the quality of gasoline to get any Better. (that's just me, always an optimist) LOL
Dumb question: When you change to a modular pulley, do you have to get a smaller belt or anything else or is it just change the pulley and go ?
By the way, what is the stock pulley - 3.8 ?
The stock pulley is 3.8...U can use the same belt down to a 3.4 pulley....Belt will of course not be as tight but with that large of a pullwy there is no issue..
The stock pulley is 3.8...U can use the same belt down to a 3.4 pulley....Belt will of course not be as tight but with that large of a pullwy there is no issue.
Thanks. It looks like that might be my first easiest upgrade. The rocker arm, springs and retainers change frightened the mechanic when he looked at the side of the engine underneath the back window (he didn't think he'd be able to get to everything he needed to change).
Thanks. It looks like that might be my first easiest upgrade. The rocker arm, springs and retainers change frightened the mechanic when he looked at the side of the engine underneath the back window (he didn't think he'd be able to get to everything he needed to change).
If changing rear springs and rockers scares ur mechanic then u should start looking for a new mechanic...Not a hard job at all..
I would also like some input on pulley size... I have a SIII (So GEN V M90). Engine is pretty much stock for now. I have a wideband and DHP Tuner. I guess I can upgrade injectors and depending how difficult, I can pop a cam in there... I just really want to get it running nice before I upgrade things and end up chasing my tail...
If changing rear springs and rockers scares ur mechanic then u should start looking for a new mechanic...Not a hard job at all..
Exactly. When I first got my 3800 started in the car, it started pouring out smoke because the incompetent machine shop that did my heads installed wrong valve seals, I replaced all valve seals in the matter of about 1 hour IN THE CAR.
------------------ 86 Fiero GT 4spd - L67 swap: VS cam, GenV 98 GTP - Some mods
I would also like some input on pulley size... I have a SIII (So GEN V M90). Engine is pretty much stock for now. I have a wideband and DHP Tuner. I guess I can upgrade injectors and depending how difficult, I can pop a cam in there... I just really want to get it running nice before I upgrade things and end up chasing my tail...
I have a 3800 SC series III engine modified to a Series II type to get away from drive by wire. It has a N* TV, VS cam, larger injectors, intercooler, and a tame/reliable tune. This engine still dynos at around 300 HP and 300 ft lbs of torque at the wheels. I believe that I can run a 3.2 or 3.0 pullet with very little change except for a new tune. I actually have a 3.0 pulley sitting in the basement but have not installed it because I am lazy and really do not need any more performance.
what everyone is saying is that its possible to run the 3" pulley, EXEPT if you haven't tuned the computer to compensate for the increased boost, its going to run a little off of where the correct air/fuel ratio should be, enough so that it could ruin the motor from running too lean in this case.
im learning about this with the cam manufacturer I have and the tuner im in contact with, too high of boost, or too low of vacuum from where the stock tune is set at and you're going to run into either being too rich or too lean.
ALSO have to mind the ignition knock (ping) with the kr monitoring. the s/c engines tune wasnt meant to run 87, they can but they shouldn't... 93 is probably what every performance build will end up using, if they care about their engines... OR they tune for it.
what everyone is saying is that its possible to run the 3" pulley, EXEPT if you haven't tuned the computer to compensate for the increased boost, its going to run a little off of where the correct air/fuel ratio should be, enough so that it could ruin the motor from running too lean in this case.
im learning about this with the cam manufacturer I have and the tuner im in contact with, too high of boost, or too low of vacuum from where the stock tune is set at and you're going to run into either being too rich or too lean.
ALSO have to mind the ignition knock (ping) with the kr monitoring. the s/c engines tune wasnt meant to run 87, they can but they shouldn't... 93 is probably what every performance build will end up using, if they care about their engines... OR they tune for it.
No....u need the right MODs to run a 3.0 pulley..Wether it be an IC, cam, headers...Injectors, E-85..ect Running a 3.0 pulley by just changing tunes is not the way to go about it..
I decided to go smaller on a pulley and installed a 3.4" on my series III that has the Gen V supercharger. The increase in boost was very significant. Even with the improved exhaust, 180* stat, Autolite 104's, large CAI system, LS1 MAF , N* Throttle body it became impossible to remove all of the KR's. More fuel and even a slight cutback in timing didn't change that. Finally went back to the OEM settings in the tune w a tiny bit more fuel at AE, and installed a ZZP SSIC. Problem solved. Now my experience was with the series III 3800/gen V supercharger. Results on a series II engine will be different but with a 3" pulley I really doubt that you will run knock free without an intercooler.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
When I built my gp and it was a series 2 up I went for a 2.8" (it was free). And I was running pretty mucj the same setup. Had horrible kr.. until I ran an alky/meth setup then it was "driveable". I was still scared to get all the way into it esp on a hot day. The fiero is alot lighter and helps with kr but honestlly you need extra cooling. Whether its a stacked ic or a alky/meth injection setup.
E85 will make things a lot more safe. You could run a 2.8 pulley no problem as long as the injectors can keep up. A few guys made more power with E85 after they removed their intercooler.
True words.
------------------ 84/87 NB, 3800SC, E-85, VS Cam, 2.8 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, Regal GS Gauges, S-10 Brake Booster. 1/4 mile -11.85 at 114mph
