Thread: Start of mods

If it was my car I wouldn't put a 3.5" on a stock car, in fact I don't have one on mine.

Check out this link for some ideas on where to start:
http://www.grandprixforums.net/f81/s...car-17482.html

will it take it? yes.

will the car possibly be slower because of lack of timing? yes.

Originally Posted by gerhardt02

I recently bought a completely stock 02 gtp, and got rid of the 5.0 mustang. I have read that a stock motor can handle a 3.5 pulley, but I cant afford to blow the motor. What is the best approach for this car? I'm purely asking since I have extremely limited experience with this motor, and I want to know the best/cheapest way to start.

start off by making your own Fender wall intake and then get rid of the front exhaust manifold and replace it with a Powerlog(ZZPerformance makes these) and also replace stock exhaust downpipe with bigger one including U-Bend delete) OR you could just read the safely modding your 3800 thread.
Live it, learn it, love it.........

Glad to see you got rid of the 5.slow

Hope you enjoy your GP......

Read that thread Mystic posted...

Originally Posted by nickbuol

I am just starting down this path with my 2000 GTP and I am basing my plans off of bluegtp91's thread that Mystic posted above.

My new downpipe came yesterday, FWI from TDC (member here) is coming today. I will be sending the stock downpipe back to ZZP for a $50 credit towards their PLOG. I already did most of the maintenance items, flipped my dogbone (free mod), and put in a 180* thermostat while I was flushing my coolant. I will be doing the Seafoam clean (not the part where you put it in the oil, but the rest) and will at that point go to Autolite 104 plugs to go with my newly installed plug wires.

That will get things breathing right, and running cool. Then I will look at putting a 3.5" pulley in and getting a PCM or a tune if I can find someone around me to do it. I could probably go to a 3.4" if I had more than 91 octane fuel around me, but I don't so I am staying of the safe side. Besides, this is a daily driver for me. No plans of racing or anything, so that is far enough for me.

you cant just put in the thermostat and have it work, you know that right? blue, did you touch upon this in your thread? i never really read the whole thing so im not sure.

YOU CANNOT JUST PUT IN A LOWER DEGREE THERMOSTAT AND HAVE IT WORK! YOU NEED TO TUNE YOUR CAR SO THE FANS TURN ON AT A LOWER TEMPERATURE AS WELL!

Not yet Nick...I got promoted at my bank to a loan officer so I have been tied up in training the past couple days reading these damn federal books...I'm going crosseyed...if I have time this weekend...i'd like too...or if you have any time just put in your 2 cents and I'll copy it and add it to my thread if you want to.

Start our with the basic boltons like with any other car and go from there. One thing that you do need if you plan on dropping pulley sizes is a scan gauge. These will tell you if you have KR or not. Right now I could drop a pulley size and I've got a 180* thermo, PLOG, catless 3" DP, u-bend delete, FWI, and 104s. I haven't tuned the fans yet (plan to) and I only hit 190* sitting in traffic in the Fl heat. Running 0* KR.

maybe one of these days when i get bored ill write my own journal or just copy and paste yours and edit it. just add in my own little pieces. we'll see.

Originally Posted by Bio248

you cant just put in the thermostat and have it work, you know that right? blue, did you touch upon this in your thread? i never really read the whole thing so im not sure.

YOU CANNOT JUST PUT IN A LOWER DEGREE THERMOSTAT AND HAVE IT WORK! YOU NEED TO TUNE YOUR CAR SO THE FANS TURN ON AT A LOWER TEMPERATURE AS WELL!

Nope. If I knew that, I wouldn't have done it. I was following the first "Step 6" in bluegtp91's thread where it says to do that as a "maintenance" item.

I saved the 195* t-stat. Looks like I will drop that back in and save the 180* until I can get a tune. That thread really should be changed...


So what will happen if I drive the car 10 miles in the morning (mostly highway) and 10 miles in the late afternoon before swapping it back for the original? Or do I need to make a point of doing it before that?

oh, nothing will happen with the lower thermostat in, but it just wont work how its supposed to. the car will still get nearly 200* like the stock thermostat because the radiator fans arent set to turn on at a lower temperature yet. the car will run and perform fine, but the point of having a 180* thermostat is to run the car at about 190-195* at most which you wont be able to do without the radiator fans help. you might see low temperatures on the highway when cruising, but anytime you get into traffic they will go back up.

No point to swap it out. Just wasting your time. Leave it in.

Well, it is because when these cars run cooler they last longer and when your L67 is cooler, your performance ratings = higher. You just can't run a 160* IMO because it is too cold and the car won't like it. But the 180* keeps temps down enough to keep that motor cooler. And, like I said, being a L67 and having boost...the cooler it is the better it performs.

Originally Posted by silverstreak

I agree 100%. Fuel and spark are calibrated to operate at 195* for optimum performance. Putting a lower thermostat will do nothing but hurt performance and fuel economy. Putting a lower thermostat is old school thinking. It was ok to do back in the day but not now. If someone can show me one bit of evidence where a lower temp thermostat increased performance or lowered KR then I will eat my shirt.

who works on their car and doesnt tune it to work with the newly added parts? the colder you can run your motor the more power it will make, but the faster it will go away. a 180* thermo is a good choice to run a little cooler. now, if you were to argue the 160* thermo with me then i would agree. that is too cold.