3.1? 3100? What?

[rknapp]

Ok I assume there is a difference between 3.1 and 3100. My engine says 3100 V6 on the plenum and is in a 2003 Grand Prix SE. What are my options performance wise? I looked at a timetable for this engine and it says for 2003 GM put Iridium spark plugs into the 3100, so that probably is as good as it is going to get. I don't want to do a FWI, so would a regular CAI for a 3800 work for it? Or would I need to get the Integra intake and trim off everything beyond the 45* bend for a custom CAI? Also, just what makes up the exhaust system of these cars? Is the unit that the tail pipe is attached to a muffler or a resonator, and what would replacing it with a normal straight pipe do? I don't have a whole lot of money to spend, and since that unit on my car is making horrible vibration noise, I wonder if it would be worth my while to just cut it off and leave it off performance-wise and/or sound-wise. I've read a lot about 3" down pipes, headers, heads, u-bends, 3.1, 3100, 3400, 3500, 3800, 3800 S/C. All this info I read was spread across GTP's where people stressed scanning, KR, etc. and across the generation preceding my own. It would be an understatement to say my mind is thoroughly confused and burned out.

Basically all I want to do is give the car better passing power, as from a 55-roll it took about two tenths of a mile, maybe less, to pass three cars under full throttle and having the gear selecter in '3' instead of 'D', and being that it was in the oncoming lane it made me nervous. Granted, there was about 1-2 carlengths between the first two cars, and more space between the second and third car, it still seemed like it could do better. Six gerbals SHOULD do better! Anyone who can give me a straight answer about the 2003 3100 (not a "drop in a 3800 S/C"; engine swaps are out of the question), THANK YOU! Haha. I understand there isn't much room in gaining power on a budget, much less doing so in a 3100, but anything will help.

[SappySE107]

RE: 3.1? 3100? What?

Look at the 3500 plenum swap onto the 3400 lower intake. I believe that may be the best bang for the buck. Not really sure on that, its fairly new and may not work too well with an otherwise stock motor. Nitrous helps:P There aren't any bolt in headers for that application. Tuning would be an option, which I believe digital horse power inc and hptuners both have the ability to scan and reprogram your computer. This could be the best option as its great to have the ability to scan if something starts acting up.

How much do you want to spend and how much power are you really looking for? Passing power can be taken care of a few ways but only so much can be done without tearing into the motor.

[rknapp]

Of the $1200 to my name, I want at least $600 left alone for new wheels next May (my dad is buying the tires), and I want to leave $100 in both of my accounts ($100 each) so nothing more than $400. Yeah I know, it's very limited, but I'll be coming into more money over the summer when I start working again, so I'm not really looking for intense gains right now.

What is with the DHP PCM on donkeypunchperformance.com? There is that and then there is the Powertuner. I figure the Powertuner is something that involves a lot of tweaking to get it right, but what about the PCM?

[SappySE107]

Im not sure if the DHP pcm is a programmable setup, or if DHP does a tune and thats it. You would be better off with a setup that you can tune yourself, especially if you already have a laptop. Granted, you would need to learn how to tune properly, but if you are willing to learn, there are those willing to explain (I would do my best). Germ, if he wants, could explain the DHP setup more in depth. I have seen the HPTuners setup, and its pretty straight forward from what I could see. Im used to looking at a lot more variables and such but they really didnt put anything in there you don't need.

[rknapp]

I would probably be better off with something more or less pre-tuned, but obviously since not every car is an exact clone of another, there would need to be some kind of tweaking to do. I have a laptop with which to do that (posting on it right now) so that isn't a problem, but I wouldn't know to begin to tune the PCM with it (computer programs and such), and my dad would have a heart attack if he knew I tried.

[SappySE107]

The software is pretty straight forward once you understand the basics. The key really is being able to see what the computer is doing right now, and then you simply adjust from there. Limiters and fan turn on times are a piece of cake.

[SHOoff]

All this info I read was spread across GTP's where people stressed scanning, KR, etc.

The 3800 s/c starts having problmes with KR for different reasons. They're probably spending a lot of time with the scanner hooked up to the car. Having the 3100, you're probably not going to have so much of a problem.

On the GTP boards though, you've probably seen Intense Racing mentioned a number of times. You may want to send them an email. They have a listing that they do a PCM for a 03 Grand Am GT with the LA1 (that would be the 3400, same as you got, just a bigger bore) Maybe it's possible that they can do a PCM for the 03 GP. If they can, then you're in luck. Cuz they do it for 100 bucks. Pretty good deal if you ask me.

It will do things like. Change your idle speed, cooling fan turn on, advance timing up to 6*, disable the trouble codes for the Rear O2, random/multiple misfire, EVAP and EGR, and they can change rev limits and shift points on the tranny. Each of those options are 10 bucks extra. I'm not sure what just the standard PCM comes with.

They also have parts and such. The intake you were asking about is sold there. Is says 97-03 Grand Prix. Doesnt designate a particluar motor like the rest of the cars do. About getting an intake from ebay or somewhere cheap. I dunno if you've noticed, as I found out, on the Grand Prix, the PCM is mounted INSIDE the airbox. Nice thing about the intense intake, it comes with a PCM tray to mount in the car.

Thing that sucks is though, that ususally if you dont have the L67 they pretty much leave you in the dark.

[alphaseinor]

First off... The DHP PCM is a standalone PCM that you find in the airbox.
The DHP PowrTuner is a "dongle" that you connect from the laptop to your OBD-2 port next to your console under the dash.
I chose the PowrTuner because I have lots of experience with cars and tuning (not to mention the ability of changing the errors so they don't trip a SES light when you use a high flow cat). If you have no clue what KR (Knock retard) is or why it's important, then you probably should just replace the PCM.

I personally would go with the Powrtuner and a high flow cat, Ubend Delete (you'll see it just after the cat) and get a 2-1/2" or 3" muffler from DynaFlow. If you drive on the highway a lot, you should go with the smaller diameter and a chambered muffler (turbo style muffler). I personally use a "wide open" and it really helped with the top end performance, but the chambered muffler should do just fine.
You can order these parts on ebay usually for less than $80 shipped, then your exhaust shop can weld them up usually for about $300. that should leave a little bit of cash left for the PowrTuner or the DHP PCM.

As for KR, the first run with the stock file, I had ~15* of KR (death to an engine anyone?) After tuning the fuel, I got that down to ~2 on a 3-2 downshift

[vsop4me3.1]

DHP does custom programmig for your car, send them an email and they will set you up computer wise.

as for an intake I used a one that the dealer believed it was from an acura, then ended up buying one from a civic. I cut them up and used couplers to hold them together. my first intake was the DIY from homedepot and probally the best one. follow the intercooled intake thread from clubgp. and the 60* store has some ported intakes and bigger throttlebodies.

as for exhaust, I did it wrong the first time. I started with the mufflers and went back.You should start at the manifolds and work towards the back. I'm surprised that no on is selling ported manifolds for the 3X00 yet. I also went with duals, which looked cool but performance and money wise , it was'nt worth it. definately get rid of the ubend and resonator (or replace with a 2.5"glasspack). 2.5" dp with a flex would be good, I think a 3" might be too big, but I don't know.

[alphaseinor]

The only reason why I have a 3" from the cat to the back is I have a turbo coming. The 2-1/2" would work fine, Chambered muffler, possibly a higher flow cat. Do the DIY intake if you want... you still will see more HP with the PT/DHP PCM.

[rknapp141]

During the summer I guess I'll look into doing the muffler, deleting the ubend and resonator, as well as the downpipe. Not sure yet on the cat though, but anything I do to the exhaust depends on if my uncle's shop can do it, since he said he would let me borrow the car I totalled last year (fixed now) if I ever have to leave the GP there, since I still have to get to work. That's the only thing preventing me from going into this 100%, since I need a way to get to work and have no way of doing exhaust work at home (two jackstands won't get me very far lol). The intake at least will happen, if I can get the necessary items to do it myself (accomodating the IAT and the vacuum line, for instance, plus fashioning a heat shield and remounting the PCM). Thanks for all the ideas guys, it really helps a lot.