Thread: Safely Modding Your 3800 Powered Car!!

Without further ado...here she is...I used a few people in it so I'd like to give credit to Brian (reptile), Jay (abrasive), Dave (trannyman95), 02BlueGT, ZZPerformance for all the products and belt listings, and Lee (IndeedSS) for the cam specs and comparo pics, and Nick, (01GTP) for the Header thread.

Modifying your 3800 Powered Vehicle: Safe as Stock to 12’s or Faster…


The reason for this thread...is not that I am tired of helping people, it is just that I am just tired of posting the same thing over, and, over, and over again. I feel like a broken record and no one seems to take into consideration there are many vital steps to take before jumping into this pool head first in the shallow end. This is just my opinion over the few years I have learned and gathered information and worked on these cars and have build my own with the help of so many awesome people. Keep in mind...first thing you need to know...once you start tossing things at these cars, things can break...transmission, axles, popping pistons...that's why I've got this basic guideline here to help you to modify your car as safely as possible. Also...you break it...not my problem

The first question here at hand is to see what year car you are going after, what goals do you have in mind, what budget do you have for your car? Modifying a ’97 Grand Prix is different than the ’98-’02 GP’s as well as the 2003’s are different from all the others too. Then comes the ’04-’08 Grand Prix’s. '04-'05's are tunable just as the older ones are...but anything '06-'08 WILL NEED a '04-'05 PCM to work correctly when tuned. Tuning the ’97-’03 Grand Prix’s are a bit easier as there have been way more extensive testing on them than the ‘04+ cars, even though they are still highly modded by many people as they are becoming cheaper and more readily available.

Basic info about them is that they are a GM W-Body, Coupe/Sedan, FWD, 4-spd automatic transmission (Code-Named the 4T65E-HD; 2.93 gearing) 3800 Supercharged V6 platform (Code-named L67 for 97-03 or L32 '04+), rated at 240 hp (260 horse for the '04+ cars)and 280 ft. lbs. of torque from the factory. Figure your 20%-ish drive train loss and you’ve got your basic wheel horsepower numbers. The N/A Grand Prix was also powered by the 3800 V6 (Code-Named L36 for 97-03 or L26 '04+) and mated to a 4-spd automatic transmission (Code-Named 4T65E; 3.29 gearing, Keep in mind in '04 The GTP Comp G used 3.29 gearing from the factory for a way better setup) making 200 hp and 225 (add 5 ft. lbs. for the '04+ cars) ft. lbs. of torque. If you have just bought your ’97-’08 WBody and are looking to modify it then please take these steps to insure safer modding steps. Begin with your typical maintenance first, such as:
1) New Spark Plugs (You can upgrade spark plugs at this time if you wish)
2) New Spark Plug Wires (You can upgrade spark plug wires at this time if you wish)
3) Oil/Oil Filter Change
4) Fuel Filter Change
5) Coolant System Flush (Replace Dexcool with Yellow/Green Coolant)
6) New Thermostat (You can upgrade to a 180*/160* Thermostat at this time if you wish)
7) Lower Intake Manifold Gaskets/Coolant Elbows (2)
8) Transmission Pan Drop/New GM Transmission Filter (Replace 3-4 quarts with Dexron VI, not Dexron IV)
9) New Brake Pads and/or Rotors
10) Supercharger Oil Change (Replace with 2 New Bottles of GM Supercharger Oil)

Also...be sure to check your brake fluid, tires, alignment, and anything else you can think of that I might have missed. First and foremost...get a way to scan the car for important parameters...the most vital being KR (Knock Retard). Best bang for your buck way to scan is by purchasing an Aeroforce Scan Gauge. You can buy them on plenty of the vendor sites for around $200-$300.

Now, with all of that preventive maintenance finished...and a way to monitor your car's behavior, you can start with some go fast stuff. Granted, not all cars are going to need a little fixing up, but if it needs done...it wouldn't hurt to get it done and out of the way before you start beating on it like your step child. Many comments I have gotten in the past as well as a lot of others are the poor souls who read Vendor Tech Articles and “Stage Blah Blah” Performance Upgrades and think with a Intake, 180* T-Stat, and a Cat-back that you can safely run a 3.4” Supercharger pulley. Can you do it? Sure. Is it the safest way to go about things? Not really. Too small of a pulley can cause KR. Reptile typed up a sticky as well on how harmful Knock Retard can be to your engine on here as well.


Follow these steps to surely get the most out of your 3800 Powered Car. Something to keep in mind is this is just a rough draft if you will...you can go about it however your wallet allows or what YOU might think will work...but I recommend it to go somewhere close to this order...

1) Free Modifications - To be honest there is only one free mod REALLY worth going about...Granted ZZPerformance talks all day about the TB Screen Removal, Voltage Booster, and even the Boost Bypass Modification…they aren’t worth it, and won't help at all. They were put there for a reason from the factory; Leave them alone. The only one worth doing however is flipping your stock motor mounts...seen here by Abrasive...

Originally Posted by Abrasive

You basically turn this....


Into this....


I do it just as Scimmia described, by removing the torque strut (dogbone) from in between the part pictured above and the engine brackets just to get it completely out of the way. Then with the bracket still attached to the car, put the bolt back through the bushing and tighten down the nut completely. Then I take a flat screwdriver and pry the rubber bushing back just enough to spray some lubricant in behind it all the way around. A little WD-40 works good. Then I put a 15mm wrench on the bolt head and another on the nut that I just put back through the rubber bushing and begin pushing the two wrenches towards the engine. Turn them slowly to make sure you are not tearing the bushing and sometimes you have to work them back and forth a little bit to get the entire bushing to "flip" 90 degrees. Once finished, the bushing is now solid on the front and back which is where the engine puts the most force against them as it tries to move back and forth. Then just take the nut off and remove the bolt, reinstall your dogbones, and you're done.

Thanks Jay For those wondering...this is the easy and free alternative to poly motor mounts. They won't shake/rattle/vibrate as much as Poly's but they won't work as well either. There are no "power gains" from this...it just limits the movement of the motor and translates power to the ground better.

2) Cold Air Induction - Three Words; Make Your Own. People can argue all day about the K&N, Wizaird Intake, JMB Fenderwell, MSP CAI, SLP CAI, etc., but for the price they can all be beat if you take a trip up to Home Depot, Lowe’s, or your local Hardware Store. Design is up to you guys but most people after getting to the basic 3.4" setup toss out the Cold Air/Ram Air/Hot Air/Fenderwell Intake Setup for an Open Cone Intake Setup...which is just a Cone filter on the end of the Throttle Body (Or in the '04+ cars...bolt a filter to the end of the MAF Sensor).
Cost: $30+
3) Lower Temperature Thermostat - Easy mod for your WBody as the stock T-Stat tends to run a bit hot, above 195*+. Throw in a 160* or 180* Thermostat from your local auto parts store to keep that motor cooler. Cost: Less than $10
4) Spark Plugs - Change out those stock spark plugs with new ones to restore any lost power. Brands that most tend to go with are either Copper Core Autolites or NGK Spark Plugs. Get these at your local auto parts store also. They range as follows in order from hottest to coldest plugs...remember...you want the hottest spark possible...so running a super cold plug on a larger pulley to combat knock isn't the best plan...ACD's, AL606's, and AL605's are basically for stock cars or very small bolt ons still running the stock S/C Pulley or modded N/A guys...you want to keep a hot spark. NGKTR55/AL104's for your 3.4" Setup, TR6's are a tad cooler...best used around the 3.25" pulley area, and AL103's...are for the extreme supercharged application...3.0" pulley or lower. Here is a picture to reference the firing order and the correct coil number if yours aren't numbered or you just need a quick reference picture: http://i33.photobucket.com/albums/d6.../plugwires.jpg

AC Delco Factory Replacements: Stock
Autolite 606: Stock
Autolite 605: 1 Heat Range Cooler
NGK TR55: 1 Heat Range Cooler
Autolite 104: 2 Heat Ranges Cooler
NGK TR6: 2 Heat Ranges Cooler
Autolite 103: 3 Heat Rangles Cooler

5) Spark Plug Wires - If you need some new wires, opt for the stock Lifetime Warranty Auto Parts store brand from your local auto parts store, but if you want to upgrade and need new wires now is a great time. Coil Packs, leave the stock ones...don't waste your money on MSD's as they are actually proven to fail within a years time and put out LESS spark than stock units. Companies that offer aftermarket plug wires are MSD Ignition, Taylor Wires, and PRJ Performance. All ranging from 8mm to 10.4mm monster wires. Cost: $60-$120
6) Exhaust - Here is where a lot of misconception tends to occur. Many people think that when someone says exhaust work that they can run 3” straight pipe from the cat back and drop to a 3.4” pulley and think that they have done enough exhaust work. Hardly. The cat back is the least of your worries as is flows good enough and has been dyno tested to not show signs of flow issues until 350+WHP, which is around 400hp at the crank. Exhaust modding should be done as follows:

Powerlog Front Manifold – The Front Manifold for any 3800 was casted very poor from the factory. Replacing it with a high flow unit from ZZPerformance gets rid of that nasty stock manifold, lowers KR, and gives you a few more ponies.

Cost: $120+

Downpipe/U-Bend Delete – One of the best mods for a WBody you can do with basic hand tools as long as you spring for the bolt-in type DP. The Downpipe and U-Bend are both hands down the most restrictive part of the exhaust system on our cars. If you ever plan on buying headers you will either have to demod to install them or wait and buy headers to being with. If your modding is not going to be very intense or internal, then the PLOG/DP setup is right for you. ZZPerformance or Hogan Performance are the only places where I would get a Downpipe from. For you GT guys if you ever plan on Top Swapping your L36 motor or you GTP guys that have minor to mild bolt-ons, lean towards the 3” Downpipe, Catted or Race Pipe, that is up to you as there is no more gains in a de-catted car to one that has one. If you are a GT/GTP guy and want a cheap weld-in Downpipe...then go for the Shorty DP. GT guys tend to go for the 2.5” as being N/A doesn't warrant the need for a 3" downpipe.

Cost: $89.99+

If however...you want to skip the Downpipe/PLOG and go straight to headers...don't worry about those ^^ steps...Headers come with their own downpipe and work on any 97-08 car...supercharged are not...they are all the same design exhaust wise from the factory.

Headers – If you have the money, just buy them up front. Installing headers means you don’t have to worry about the Powerlog, U-Bend, or Downpipe. Flow is unmatched by any other exhaust setup and there are many brands out there to choose from. I have Pacesetter’s and love them for the price. Recently SS Autochrome or even EBay companies just as DNA or Speed Daddy have came out with SSAC/SLP knock off headers...choice is up to you.

Cost: $195+

Cat-Back Exhaust System – If you are done with all of your other mods exhaust wise and still want a different sound, look into exhaust systems. You will not gain any sort of power increase from this, in fact, it is rumored cat-backs can harm these cars’ performance ratings. I won’t go into detail but there are many systems out there available. Prices are for pre-assembled bolt-in kits with everything you need to replace the factory unit.

Cost: $379.99+

7) - Tuned PCM (Performance Control Module) – This is hands down the best mod for the 3800 powered car in my opinion. A tune makes or breaks these cars so do not skimp here. There are only a few reputable companies left as many have closed shop or do poor tunes. Here is where I will say it again, BUY ZZPERFORMANCE TUNED PCM’s AT YOUR OWN RISK. Their support is for the most part horrible and I had to send mine back FOUR times and it was still wrong the fifth time, and keep in mind my GTP was my Daily Driver. It ended up toasting my motor a few months after having it installed (car had about 40K on it so there was no high mileage or neglectfulness at fault here), so in short, if you want to buy one, go for it. Don't come back here crying if it doesn't work. The company's people have had great luck with is Will at Overkill Motorsports or 3800 Performance, who sells the original Digital Horsepower Tuned PCM. You can also look up Reptile here on the forums for a basic 97-02 PCM. Other than mail-order tunes, you can buy a laptop tuner and go to town. Learning to tune is an awesome skill and will come in handy farther down the road. Digital Horsepower Inc. (DHP) used to be the only tuner available, but now since they have closed up shop; HP Tuners is the only program you can purchase new. All in all...Get a tune. Your car will love you for it and it'll run GREAT when you get it dialed in correcly. A few things to note is ’97 PCM’s are not compatible with any other year as the same with the ‘03’s. ’98-’02 GT/GTP PCM’s are interchangeable.

Cost: $100 - $700+

So for the most part now minus the pulley swap you have run into a nice road block. Here is where you need to decide how far you are going to take your WBody Build. If you would like to continue with just bolt-on performance modifications I’ll list the few more that are pretty basic....

1) ZZPerformance Exclusive HV3 Upper Insert (Non-Supercharged Cars Only) – For you N/A guys this is a great mod. For the money it is said you will see gains of around 20hp or more and for a N/A car that is awesome. It is a very straight forward install also as all you do is remove the Upper Intake Manifold (Or Plenum) and place it inside of it. Comes with everything needed to install also. Cost: $200+
2) Ported Throttle Body – For both WBody cars this is a great mod that will not so much give you a huge horsepower increase but will net you that lacking throttle response you’ve always wanted without having to drop a big lump sum on a aftermarket Billet Throttle Body or convert your car to a L67 Throttle Body(N/A guys), Northstar, or LS1 Throttle Body’d car. Throttle Body porting can be done fairly cheap too. If interested, shoot Reptile a PM on here. Same person who wrote the sticky about KR I had mentioned earlier. Does amazing work, quick turn around, and for the price…you honestly cannot compete. The butt dyno will love it too Cost: Check out the website @ Green Bastard Performance

3) Ported Supercharger Case (GTP or Top Swap Only) – This is another great bolt-on mod which I stand by very much so, basically because there is nothing like hearing the blower whine A LOT more than it already does. Porting the inlet and outlet of the supercharger case not only increases flow capabilities of the supercharger itself, but also with the increased flow comes lower temps radiating from the case itself. This will not only increase horsepower/torque figures, but you will also be able to hear the supercharger whine more, or whistle more at idle, and since it dissipates heat faster, you are lowering KR levels at the same time. Great to couple this with a Ported Throttle Body at the same time. Again, PM Reptile on this one too in my opinion...so again...use the link provided above.

Now for you supercharged guys, here is the most fun part I think, the infamous pulley drop. Yes, more boost. Now that you have the mods to safely run a smaller supercharger pulley there are two options to boot. One is you are going to keep this pulley size or two; you are going to continue to mod your car and eventually go with a smaller pulley. As of now your best bet is a 3.5” or 3.4” Pulley. You should be able to easily run knock free with that size pulley. Keep in mind when you do drop pulley sizes to maximize power, drop to a smaller supercharger belt with the sizes seen here taken from ZZPerformance to eliminate any sort of belt slip you might end up with:

667 - GTP/GS/SS supercharged with stock 3.8" pulley (67 1/4" -1708mm)
658 - GTP/GS/SS supercharged with 3.2 - 3.5" pulley (66 3/8" - 1687mm)
650 - GTP/GS/SS supercharged with 2.9 - 3.1" pulley
645 - GTP/GS/SS supercharged with 2.6 - 2.8" pulley

716 - Bonneville SSEi with a 3.4" pulley
721 - Bonneville SSEi with stock supercharger pulley (72 5/8" 1845mm)

Riviera/Bonneville use same length belts...

Stage 2 or 3 Intercooler (S2IC/S3IC)
685 - 3.3"+
680 - 2.90" - 3.20"
675 - 2.6" - 2.8"

Short Stack Intercooler (SSIC)
675 - 3.25" - 3.5" pulley
670 - 3.2" pulley
667 - 3.0" pulley

Accessory belts
915 - Stock accessory belt for Series II '99-03 (works with either UD WP pulley or OD alt pulley but not both) (2340mm)
923 - Accessory belt for Series II '99-03 with UD WP pulley and alt UD pulley (2360mm)
905 - Stock accessory belt for 04+ Grand Prix Series III
935 - Stock accessory belt for 97/98 (94" - 2367mm)
938 - Accessory belt for 97/98 with both underdrive pulleys (2400mm)

SS M90 supercharger kit for L36
970 - SS M90 for 97/98
955 - SS M90 for 99+ 4.0"- 4.2" pulley
950 - SS M90 for 99+ 3.8"- 4.0" pulley
947 - SS M90 for 99+ 3.5"-3.8" pulley

Meziere electric water pump
875 - Series II 99+ accessory belt with Meziere electric water pump
864 - Series III accessory belt with Meziere electric water pump
895 - 97/98 with Meziere electric water pump


1) - Press-On Supercharger Pulley – Just as the title states. This pulley is the same as the stock idea as the smaller pulley is pressed on the Supercharger snout with a special Pulley Tool that companies such as ZZPerformance rent out or for your best bet try to find someone that knows how to do this close to you to save you a load of money. You can buy them fairly cheap but I think no one should get them, just spring for the M.P.S. Otherwise, a great buy. DO NOT attempt to use a everyday pulley puller from the Auto Parts store down the street or you'll end up buying a new supercharger snout when your done.

Cost - $60~

2) - Modular Pulley System – This another one of those “Must Have” parts for your Supercharged Grand Prix. This is an interchangeable pulley system that is offered by a few companies, such as the most popular ZZP Performance Modular Pulley System (ZZP MPS), Thrasher M.P.S., Pulley Boys Quik-change System, etc. Basically instead of having to take at least an hour of your time using a pulley puller tool to remove the old press-on pulley and press-on the new, smaller pulley, these quick changing pulley “hubs” allow you to swap pulley sizes in a matter of minutes with 5-6 Allen Head bolts. The kit you will buy most of the time comes with one pulley and everything needed to install them except for the puller tool.

Cost: $100+ for the kit, depending on who you go with and around $50 for the interchangeable pulleys.

And because I ran out of room and hit the 25,000 character limit LOL

Here is the rest of it...

Now you have hit yet another big crossroad in the mod process. If you are still seeking more performance from your GT/GTP Grand Prix here are some of the big steps a lot of people tend to take. This includes: High Ratio Rockers, Intercooling, Camming, or Top Swapping. The following is what I have learned coming across going beyond bolt-on parts.

1) - Top Swapped 3800 V6 (GT Only) – Don’t cry you non-supercharged guys, there is still hope on how to lay a smack down on a factory supercharged car and that lies within your block. Yup, Compression Ratio. Higher Compression means a few things for you who go the top swap route. One, you will make more power on the same sized pulley as the factory L67 powered car. Two, High Comp. loves boost. Comparing the stock L67 comp. ratio of 8.5:1 vs. the factory GT Comp ratio of 9.4:1...you can see why, as it is almost a full point more of compression. It IS easier to blow motors with too much boost on high compression with no enough flow, but when tuned correctly is a very lethal combination that will beat most cammed and intercooled L67 cars. This isn’t the easiest thing to do, nor is the hardest, you do have to tear the block down to the heads.

Cost: Depends on who you know, or if you're handy roaming through junkyards...but on a budget, most start around $500~ for a GenIII Swap, and go up from there.

2) - High Ratio Rockers – Thankfully GM made one thing simple…pushrod motors!! Stock GT/GTP cars came with 1.60:1 or 1.66:1 Ratio Rockers from the factory. There are a few choices that you have here to make some more power by letting those valves open more...
a) Modded Stock Rockers – ZZPerformance decided to elaborate on the efficient stock design for those wanting more performance on a budget. ZZP introduced the 1.90:1 Modded Stock Rockers. Basically, these rockers start out as stockers. The seats are welded in and ZZP re-machined them to achieve a ratio of 1.90:1. Great and easy way to add about 20 horsepower without having to change valve springs. As long as you keep your shift points at or below 6,000 RPM you will be fine. Anymore and the stock valve springs tend to float.

Cost: $275+

b) Roller Rockers – If you want to upgrade your valve train and have the money to do so and are going the rocker route then Roller’s are right for you. Roller Rockers are a lot lighter and are much easier on the valves than the stock or Modded Rockers, but come at a price. Much more expensive than the Modded Stock Rockers for about the same performance gain. Roller’s come in the ratio of 1.60:1, 1.70:1, 1.80:1, 1.84:1, 1.90:1, and 1.95:1. Anything higher than 1.84:1 ratio is going to be needing valve springs to compensate for valve float as long as you are going to be shifting higher than 6,000 RPM’s. LS6(#90) or L76 Springs are great and cheap for this upgrade, but you will need retainers too. These are a great alternative to a cam budget wise and you still retain very stock drivability and some have even reported better gas mileage. Keep in mind you will benefit even more from a custom tune afterwards. Also remember that if you ever go with the cam route, you will have to sell the rockers as you can only run stock 1.6 ratio with a cam for the most part...unless you want to combine a higher ratio rocker with the cam you just installed for a crazy amount of lift.

Cost: $399+

3) - Intercooling – This right here is probably another one of those, “If you have the money, BUY IT” mods. Proven to be the best knock killer in most cars along side of Methanol Injection. Available to you are the Short Stack Intercoolers, Stage 2 Intercooler, and Phenolic Stage 3 Intercooler. All doing the same thing, cooling the compressed air from the supercharger and shoving all of that cooled air into the motor for a denser charge. For anyone planning on going the IC route, let this be known. Skip the Short Stack. Save your money and buy at least a Stage 2. The Short Stack is half the price, but you get what you pay for. They heat soak very quickly and are just not really thick enough to do any good, plus they have had warping issues. Obtaining a Stage 2 or 3 IC will allow for 3.25” or lower pulley drop on a stock car. This was the idea back in 1996 in the concept car GPX, but GM didn’t go through with the design, which was in my opinion a huge mistake as it would have made the GTP a VERY fast car. Also keep in mind that if you do happen to get away with dropping lower than a 3.1”/3.0” pulley, your stock fuel injectors will probably run static (out of fuel) and you’ll need bigger injectors. Also to run along with this is the kind of IC Pumps and Heat Exchangers you will buy. This is honestly up to you, just I’d just go for the bigger H.E. you can find and the GM Pump as it might run you more but will never break down on you.

Cost: $600+

4) - Camshafts – Camming your GT/GTP is one of those advanced level mods. It entails either doing it while your motor is out by pulling the balancer and front cover and a few other small things, OR, Dropping the motor mount and pulling the cam out through the wheel well, which is a nice alternative for those not comfortable with pulling the motor all the way out. There are many choices of cams out there. Most guys that don’t want anything crazy or are intercooled tend to lean towards the VS Cam...it is a proven cam that really does the job still running on the stock valvetrain. Many people have taken the VS well into the 12's and 11's with the right tuning and setups. Next on the list of the VERY popular XP or Intense-Racing S1X cam…both intended for a more aggressive idle and more useable and readily available powerband. The XP is a higher RPM cam while the S1X uses the 3800 mid and low range grunt. Both of those cams WILL require stronger valvesprings and matching retainers...at least of the #105 strength. Anything past those WILL require head work to function to their fullest ability, and anything needing clearance will require milling valve guides in your heads...Such as the Intense-Racing Stage 3 Cam, Comp Cams XPZ Cam, Thrasher Race Cam, or the Intense Stage 4 Cam are very radical and harsh, but make LOTS of high RPM power...but are only useful with the correct supporting mods and little pulleys to keep the air flow levels high where it helps these types of cams to shine.

Cost: $300+

5) - Pulley Drop – Yet again you supercharged guys have the chance to drop pulley size yet again with rockers, intercooler, or a cam. The most popular pulley to drop from after the 3.4” is the 3.25”. Some of the intercooled guys go smaller but it really isn’t needed if the car is tuned right. Also, dropping lower than a 3.1” pulley will run the stock #33lb. fuel injectors static and you will need to upgrade to #42.5lb. Injectors…#60 ones are way overkill.

Cost: $50+ for the pulley, $250+ for Injectors

I want to thank Turbo Kent ahead of time for taking time to send me a PM about his spill on the turbo side of the 3800...so here it is.

Turbos: Another way to add performance to your car is with a turbo. Kits are sold by ZZP, and Cartuning Performance. And depending on how knowledgeable you are there have been a few that fabricated their own.Both venders offer several options on the specifics of their kit depending on how much of a monster your looking for, but keep in mind you cannot get the best turbo kit available with out have some other supporting modifications to go with it (i.e. Transmission, injectors). Most kits will take about 6 hours for someone that knows what they are doing and plan on 12 if it's your first time. Best to take it slow and read all directions twice and double check when finished, because if you happen to have one critical vacuum line out of place you could end up with a blown engine. As with supercharged cars that are producing higher boost levels, Turbo charge cars also benefit from being intercooled. Intercooling allows you to increase the boost without out gaining knock or if you have knock already to get rid of it. All of the kits i've come across do include a custom tuned PCM for that specific kit/application. These are good usually for a base start but I would recommend that if going turbo learn how to tune yourself. This way you can account for other modifications you may already have. Along with that I would recommend that you also get a wideband gauge to see where your AFR is, now you can install it permanently or just use a temporary one for tuning. It is easy to get your fueling a little lean because the turbo can be building boost even when your well below Power enrichment throttle level. If you do start going lean you can end up chipping the top of your piston which is a whole other nightmare or causing detonation. Also keep in mind what your boost limits are, for a stock NA car that just put on a turbo kit you don't want to have boost above 9psi if you are not intercooled. Kits range in price from around $2400 to $3600, don't for get to figure in the cost of a intercooler(optional), boost gauges, and if you have a stock tranny plan on replacing it soon.

Now most people would be running out to the track to go beat the crap out of their new found power. But, here comes yet another weak point in the Grand Prix modding process, the transmission. Most people with lose the 4th Shaft first, or shred differentials all together. From what I have heard, ’97 GTP’s have harder input shafts, but don’t quote me on it. ’97 GT cars should be steered clear from. If you plan to mod and have not bought one yet, don't. They use a very weak vacuum powered transmission that is prone to crapping out quickly after you top swap them or heavily mod them and beat on them with just the N/A motor. ’97-’02 GTP’s use the 4T65E-HD Transmission with 2.93 gear ratios which are great for highway mileage and ¼ mile runs. The ‘03’s were supposed to be changed to the ‘04+ body style but GM didn’t get around to doing it then, so the ’04 transmission was thrown in all '03's. It had the Hardened 4th Shaft which most people upgrade to in built ones from the factory and it had a completely different valve body which makes them harder to tune and not compatible with any other year PCM’s, all from the factory. Mine being a 2003 year model, I saw numerous sub 1.9X 60 foot times at the local drag strip and I shredded a differential just once. Everything else in the transmission was fine, when I tossed it. Surprisingly it took that much abuse, it served its purpose and I upgraded to the ONLY transmission you should ever consider for your ‘97+ Grand Prix…a Triple Edge Performance Transmission. See Dave here at: Triple Edge Performance - Home Page .

Not only is he a great guy, he has great customer service and his slap-bang, crazy ass transmissions are AMAZING for the price and quality. And if you happen to be in the Midwest around the Kansas City, Missouri area and don’t feel like driving all of the way to Indiana for a transmission install, Green Bastard Products will install it for you as they are Certified Triple Edge Transmission Installers. GBP Inc. is who installed mine and I got to work on the first ever local transmission install (Brian's transmission he won at the 2007 BGPM)…sure was time consuming but I learned so much from that!! After the install, get her all ready to go and hit the track. With Dave’s transmission built to spec you can be pulling 1.6-1.7 60 foots all night long with slicks. Talk about dropping time off your 1/4 See a little bit of Dave's work in action here...just a 3.5" and 1.84 roller rockers and a few other small things... http://www.youtube.com/watch?v=XdklbR98OyM

I know for sure there is probably way more info out there but I wanted to cover the basics and give a little info for the people after that. I know I am no expert and I know for sure I didn’t cover tuning, engine accessories, suspension, brakes, etc. But I just wanted to get across the typical 3.4” or N/A setup and beginning mod list of the average 3800 enthusiast. Hope you guys get enough info out of here as I took the time to write it and we won’t be getting AS MANY…”Hey I just got a GTP and put a 3.4” pulley on it…what should I do next?” threads Just read, read, read…that is what has helped me learn everything I have and one last thing…have fun with it. Mod safely and you will have a fun DD, track bruiser, or both and the best part it they still get great MPG’s and can haul 5 people while the Corvette you might be walking away from can only hold 2!!

Here are a bunch of websites to get you guys started:

www.zzperformance.com
www.3800performance.com
www.intense-racing.com
www.tripleedgeperformance.com
www.getoverkilled.ca
http://home.comcast.net/~greenbastard/GBP/index.html
www.moradpartscompany.com

Thanks for reading…now enough with the stupid questions

Nick