Before I get dismailed I just did a forum search under PCM and didn't find my answer so here goes. 1986 GT with 5 spd Getrag and 1998 Buick GS 3800SC. To my knowledge, the engine is all stock and is running the stock 3.8" factory supercharger pulley. The exhaust has two very small mufflers, but is running the stock manifolds. The car has other mods, but I don't think anything mechanically has been done to the engine. It runs great now FYI. I want to coax a bit more power out of it, but don't want to go with additional exhaust, headers, camshaft or intercooler. Maybe some day, but not for a while. I'm considering either the 3.4" or 3.5" ZZP press on pulley. I didn't see anything in ZZP's info regarding their PCM being applicable to a 3800 with a manual transmission. I know that there are forum members who reflash PCMs, but I don't have their forum names or other contact info. I presume that I should have the PCM recalibrated to prevent KR or other associated gremlins. Hoping that someone will point me in the right direction. Opinions regarding whether to go with the 3.4 or 3.5 pulley with my set up are welcome. I appreciate all the performance mechanical upgrades that members are doing with their cars, but I don't want to do more than the pulley, PCM or any other minor associated items (thermostat/spark plugs) at this time. What do you think>
One modification usually leads to another. The best way to choose your mods for a smaller pulley is to go with the build sheet recommendations on [url] www.zzperformance.com [/url] These guys have been building performance 3800 engines for many years and have a wealth of experience to share. Basically you will need colder plugs, a 180* stat, a CAI system, and a free flow exhaust w a 3.4" pulley. Without the additional parts you will get KR's. Having done a few swap installations first hand, I can tell you that the ZZ recommendations are right on.
------------------ " 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 "
[This message has been edited by Dennis LaGrua (edited 02-07-2014).]
PCM changes are not needed until you are looking at changing fuel injection items (maf sensor, injectors). Up until that point "tuning" is just a way to convince people they need to pay money to make horsepower, which is not ever true.
I disagree,getting rid of Gm's excess crap like abuse mode and torque management (esp. With ETC) as well as really rich PE,fan temps and a number of other things are a very good reason to have the pcm programmed. But no sense paying a bunch of money on it till you have furthur enhanced stuff like dh mentions,unless you go with a cold enough thermo that the closed loop settings need corrected. If it's a buddy doing a $50 "tuneup" on the pcm than that would be worth it imo if you aren't planning major mods for awhile. But yeah,don't pay a "tune" price if you don't need it. If you just need something flashed for a change try just putting up a thread in the wanted section. Alot of us aren't limited by licenses and can charge whatever we want,and simple stuff is just that-simple lol.
Drop to a 3.4 pulleyif u have a good open intake and exhaust setup. Nosrac is local and can cut u a pretty good tune for ur setup. If interestdd in going to a MPS setup I have 2 SCs with MPS hubs already pressed on would just need a pulley.
If you are using a manual transmission in your 3800 SC swap, then you'll definitely want a tune made because the stock auto trans tune isn't going to play nicely with the manual trans. Things like torque management should certainly be disabled in any manual trans tune (but there are reasons for keeping it if you were going to use the 4T65-E auto trans - but that is a topic for another thread).
Having said that, I would recommend you have a tuner who is familiar with Fiero swaps make your custom tune for you and not someone like ZZP or any of the other Grand Prix tuners. I've heard of too many people having problems with such tunes in a Fiero because of things not getting deactivated in the custom tune so it works in a Fiero swap environment properly.
The size of blower pulley you can run will depend heavily on all the other mods you have done to the engine as well as what kind of fuel you run and environmental conditions in your area. For example, I've heard of guys having KR (detonation) trouble trying to run 3.4" blower pulleys on otherwise stock engines in areas where they can't get anything higher than 91 octane fuel. There is more to it than this but it is just an example.
I would definitely recommend you get one of those quick change blower pulley setups so you only have to press the hub on one time and then have a couple of different size blower pulleys on-hand so you can swap them out easily if you run into a KR issue. Of course, this also means you are going to need the ability to view live KR data from the PCM which can be done cheaply with an Android smartphone, the Torque Pro app, and a Bluetooth OBD2 interface. Info on this scanning setup can be found here: https://www.fiero.nl/forum/Forum2/HTML/127485.html
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
If you are using a manual transmission in your 3800 SC swap, then you'll definitely want a tune made because the stock auto trans tune isn't going to play nicely with the manual trans. Things like torque management should certainly be disabled in any manual trans tune (but there are reasons for keeping it if you were going to use the 4T65-E auto trans - but that is a topic for another thread).
Having said that, I would recommend you have a tuner who is familiar with Fiero swaps make your custom tune for you and not someone like ZZP or any of the other Grand Prix tuners. I've heard of too many people having problems with such tunes in a Fiero because of things not getting deactivated in the custom tune so it works in a Fiero swap environment properly.
The size of blower pulley you can run will depend heavily on all the other mods you have done to the engine as well as what kind of fuel you run and environmental conditions in your area. For example, I've heard of guys having KR (detonation) trouble trying to run 3.4" blower pulleys on otherwise stock engines in areas where they can't get anything higher than 91 octane fuel. There is more to it than this but it is just an example.
I would definitely recommend you get one of those quick change blower pulley setups so you only have to press the hub on one time and then have a couple of different size blower pulleys on-hand so you can swap them out easily if you run into a KR issue. Of course, this also means you are going to need the ability to view live KR data from the PCM which can be done cheaply with an Android smartphone, the Torque Pro app, and a Bluetooth OBD2 interface. Info on this scanning setup can be found here: https://www.fiero.nl/forum/Forum2/HTML/127485.html
-ryan
Wow. This is definitely the type of feedback that I had hoped to receive. Dark Horizon, MstangsBware, DefEddie and Dennis LaGrua all providing excellent information. I am running a Getrag and the swap was done several years ago. The PCM works fine with my current set up, but mechanically it is all stock. I have a fairly open exhaust (at least it's loud), but no headers or other mods. I'd like to squeeze a bit more HP out of it without changing too much. Yeah, I know that this is probably the description that anyone would like ... more power without doing much. I had hoped to just put on a smaller pulley and have the PCM recalibrated to work with the pulley so that I don't screw up a piston. I appreciate all the experience that everyone has with getting the most out of these engines, but I'd just like to push it a little further. Can I just put on a 3.4 or 3.5 and have the PCM "tuned"?
Wow. This is definitely the type of feedback that I had hoped to receive. Dark Horizon, MstangsBware, DefEddie and Dennis LaGrua all providing excellent information. I am running a Getrag and the swap was done several years ago. The PCM works fine with my current set up, but mechanically it is all stock. I have a fairly open exhaust (at least it's loud), but no headers or other mods. I'd like to squeeze a bit more HP out of it without changing too much. Yeah, I know that this is probably the description that anyone would like ... more power without doing much. I had hoped to just put on a smaller pulley and have the PCM recalibrated to work with the pulley so that I don't screw up a piston. I appreciate all the experience that everyone has with getting the most out of these engines, but I'd just like to push it a little further. Can I just put on a 3.4 or 3.5 and have the PCM "tuned"?
You can put on a 3.0" pulley and have the PCM tuned to pull all of the timing advance out so it doesn't knock - but will it do you any good? No. There is a happy medium you have to attain with pulley size and a given configuration of mods done to the engine. Running too much boost for the given mods and having to retune the PCM to yank out all the timing to prevent KR is going to give you the end result of not much (if any) net performance increase.
Other things to consider are fuel quality, weather conditions, and what you really need the car to do and how reliable you want it to be. I've seen more than a few guys break pistons because they got too greedy with boost. Is it really worth hurting an engine to gain 10 or even 20 hp? In my opinion, running the engine on the absolute ragged edge to gain that extra 10 or 20 hp isn't really worth the risk of blowing it up if you get ahold of bad fuel or something like that. My advance for the average person is to not run your engine within an inch of its life but rather give it (and your wallet) a margin of safety. Save the smaller pulleys for the day you install other mods so the engine can operate safely with the added boost.
Having said that, I would think you should be OK running the 3.5" pulley with your stated mods. A 3.4" pulley might be pushing it (or might not, but without being able to see some scan data - there's no way of knowing).
