Hello all. I am new to this site and this is my first post. I would like to say hello to everyone and am glad to be a new member in this community.

I have a 2000 GTP. All is stock except that the Ubend and the resonator have been replaced. I just bought TR55 plugs and 180F thermostat. I am going to get cold air intake and a throttle body spacer. I am wondering if I should get a 3.5 or 3.4 pulley for the super charger with these mods. Also, is the 3.4 will really be that bad on the super charger with my mods. I was also wondering what people thought about the exhaust. I have heard that the Cat and mufflers are good enough stock and that upgrading them is almost a waste of money. If they are benificial what muflers do you suggest (brand and size) and high flow cat do you suggest. My car is a daily driver and I would like it to last for a while. I dont want to mod it out and race it too hard or much. I just want some more power and would like to be able to beat most of those stupid little civics with the big ugly airplane fins that pull up next to me and rev their lawnmower sounding engine. (hope I dont offend anyone with a little foreign car) I am really dumb with any car that was made after 1982 and doesnt have a 305,350, or 400 motor. I am also curious about if I should run 91 or 93 octane with my mods and if I am on the right track with what I am wanting to do. Thank you all for your responses ahead of time.

You seem to be on the right track. As far as pullies go... a 3.4" pulley will be fine. The pulley really doesn't have any impact (to a degree) on the wear of the SC. You can throw a 3" pulley on there (I'm proof of that) and so long as you don't abuse the car, the SC will last a long time. The L67 is pretty much bullet proof.

You're going the right direction with the exhaust considering the level you're shooting for. I'd suggest getting a better downpipe (DP) and increasing the size of tubing from the stock 2.25" to 2.5" all the way back to the mufflers split. Also, replace that pipe with a true "Y" pipe versus that "T" that Pontiac uses.

Welcome and good luck,
Marc

I agree with Marc only I'd stay with the 3.4 pulley until you get some more supporting mods. The 3 inch might be fine in the winter when its nice and cold but come summer you might get more KR than you can shake a stick at. Enjoy yout GTP and welcome to the club.

Yeah... what HercMan said. I was just trying to point out (as lame as the explanation was) that your right foot has more to do with durability than the pulley size. If you're going to drop to 3.25" pullies or lower, supporting mods will be necessary.

Marc

Thank you all very much. Does anyone have any suggestions for the brand, type and size for the mufflers I should get. I read on ZZP that the stock mufflers are not restricive. Also, what should I do to replace the downpipe. Should I get a new one and where should I get it. or should I have the muffler shop fix it. I had my Ubend and resonator fixed with the O2 sensor put back in for only $50. and they did a good job.

For aftermarket mufflers it's pretty much personal preference. I'm installing a set of flowmaster 50 series.

This summer I'm picking up my second GTP. I've been mod'ing my current GTP for the better part of 7 years... back when the only company making aftermarket parts was SLP and then you couldn't get them unless you had a GTX. So, my current GTP has a bunch of old custom stuff on it.

I built exhaust from scratch and used 2.5" pipe from the cat back. The u-bend was replaced, the resonator was replaced with a Thrush glasspack, the "T" was replaced with a true "Y" pipe, the muffflers were replaced with Flowmaster 40 series, and I replaced the tips with oblong high polished slant stainless steel.

However, knowing what I know now, the GTP I'm getting this summer is going to have the following:

- TOG Headeers (already have these)
- R/T Gen I downpipe and high flow cat
- "U" bend and "T" replaced
- Tubing from downpipe to "Y" pipe will be 2.5"
- Tubing from "Y" to mufflers will be 2.25" (stock)
- Stock mufflers and tips.

After all the research I've done, I firmly believe this set up will work well. The custom exhaust I'm currently running sounds great from the outside, but drones heavily on the inside at cruising speeds.

Marc

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I just talked to a guy at a local performance shop and he was telling me that with a 3.4 pulley and CAI and the Ubend/resonator removed, colder plugs(NGK TR55's) 180F thermostat and throttle body spacer that He would not recommend upping my boost with a smaller pulley without doing something to increase fuel flow to the engine. He said that the stock PCM wouldnt adjust properly for that amount of boost and that it would be really bad on the piston heads. Does anyone have any thoughts on this? From reading alot of these posts it seems that a 3.4 pulley with the mods listed above and nothing done with the PCM and not increasing the fuel intake I would be just fine? What do you all think?

Also he said I would need bigger injectors. Is this true?

Ok just talked to another guy at another performance shop and he said I would not need larger injectors. He said depending on how my car reacts to the mods that I might need a fuel pressure regulator. What is everyones thoughts? Does anyone else have a fuel pressure regulator?

With those mods, I don't know if you would really need bigger injectors. I think your stock fuel setup should work fine for those mods since I don't think they are too extreme. If anything, I would maybe suggest getting a DHP PCM since it would most likely have all of those mods configured into it.

terapinn - see my response in your other post. BTW, considering your screen name, are from anywhere around the University of Maryland?

Marc

Terrapin.

You can go crazy talking to performance shops, and if they arent familiar with the GTP, then what they are telling you may not work well on your car even though its great for an LS1, or Ford 5.0 car.

Talk to and/or visit the websites of
ZZP, www.zzperformance.com
3800 performance www.3800performance.com
Intense www.intense-racing.com

Places like those above make their living doing stuff for our cars and KNOW what works and what doesnt. Their web pages are full of tech articles and info telling you what works what doesnt and how to go how fast for how much. There is a performance recipe page on the Intense website. check it out. The michigan group has a helpfull page too at www.migpc.com/Modifications/modifications.html.

IMO do the basic mods as you listed and get yourself a modular pulley system like DialURBoost, or ZZPs modular pulley system. There are a lot of others. Start with the 3.4 or 3.5 and see how things work out. That way if you want to go smaller, its easy to do so. If not, then you can stay where you are.

Get an LS1M (www.ls1m.com) or autotap or some sort of diagnostic software and see how your motor is running and reacting to the mods. You can learn a lot of that stuff by cruising the boards and asking questions. (where Im at now)

Smaller isnt always better. A a car can run faster with a 3.5 pulley and a 1 or 2 degrees of KR than a car with a 3.2 pulley and 10 deg of KR.

I dont think you will need to worry about extra fuel until you get nuts witht he car like larger blowers, cams, rockers, headers and tiny pulleys.

This is from ZZPs what not to buy page: Intense racing pretty much says the same thing.

Adjustable Fuel Pressure Regulator:
On many boosted cars fuel pressure needs to be raised as boost is added to compensate for extra air. The Grand Prix uses 2 methods to control fueling which render an AFPR worthless. The MAF sensor on the car reads the airflow and tells the PCM how much air is coming in and therefore how much fuel to deliver. As you mod and increase flow the MAF reads more and increases fuel. The stock FPR changes fuel pressure with boost. As your boost increases so does your fuel pressure. By changing this function by replacing the factory regulator you make your car impossible to tune. Adding fuel pressure doesn't change the maximum pressure because your stock pump is limited to low 60's in psi. So even though you might add 5 pounds at idle and cruising you're not adding that much at WOT. This makes tuning the car a nightmare. All the ZZP cars run stock regulators. If you have an aftermarket unit on your car, sell it and go back to stock. Thank us later...

Walbro fuel pump
If you have an M90 on your car then your stock pump is capable of flowing enough fuel. Our 97 GTP put down 410WHP using a stock pump, our 2000 Monte Carlo (L36 200HP stock engine) put down 387WHP with the stock pump. Changing your fuel pump greatly increases the chance of pump failure or problems due to hoses coming off. If your stock pump is still working keep it! Another down side to the in tank Walbro is the fact that it won't suck your tank dry. Your factory 17 gallon tank will be reduced to a 15 gallon capacity.

Jeff

Thank you all for your help. It has been so very beneficial to a guy that has never worked on a car with a PCM. I have always had 79 or older TA's and Z28's.

Marc, I am from Oklahoma City unfortunately. I got my screen name from a Greatful Dead poster when I couldnt think of anything. They have an old song called Terapinn station. LOL

Gotcha... I was just thinking that if you were from around the Washington, DC area you might want to attend a couple of the local get togethers. The WDCCGP was the first club on the East Coast. There are now three other clubs in that general area and all of them are pretty active. Particularly now that spring is around the corner. I don't know what kind of local interest there is in you neck of the woods, but see if there are any local meets you might be able to attend. Chances are that if there are any meets, some of the cars will have most of the mods you're looking at. You would then be able to talk with other folks that have already reached where you want to go and can ask questions and see stuff for yourself.

Good luck,
Marc

Unfortunately the closest club I have been able to find is in dallas some 300 miles away. Which I still need to start talking with since it's not really that far. Thanks for the invite though.

There's one in Kansas City too, but that would be just as far away for you. Actually, there will be a meeting this summer in Wichita and that's not too far away from you. If you are interested, let me know.
green

Yes I would love to go to wichita. Give me some more info please.

How about us Canadians in the group?!?! We need to do a Canadian gathering!!!

Sorry to get back so late. I have tried to post the link below.

http://www.weatherbase.org/kccgpnew/forum/

Get a 3.4 modular pulley from Intense and either the Wizaired, MSP, or Thrasher CAI. Do not get the throttle body spacer, it won't do anything unless you are going to a smaller pulley, but only after headers, rockers, cat, and exhaust. In fact if you wanted to keep everything sounding and driving stock but get into the high 13's, do the Intense modular 3.4 pulley, larger tensionor pulley, Gatorback 660 belt, Autolite 104's, and CAI(SLP with a K&N filter is the quietest). You already have the 180 stat and downpipe/ubend replaced. Those mods will cost you about $500.00 including install and get you into the 13's. If you have anymore cash, get the DHP PCM($294.00 plus $125.00 core charge). If you're looking for an exhaust, make sure you keep the resonator in and get resonator tips unless you like a lot of noise in the cockpit.

Autolite 104's????
What is this.

I already ordered the TB spacer, 3.4 pulley and SC oil from ZZP. Several different people I talked to said that I would need a TB spacer to run a 3.4 vs the 3.5. I have had a few people tell me that the TB spacer, 180T stat and the cooler plugs are what would help eliminate KR using a 3.4 pulley versus the 3.5.

What is different with the Intense pulley compared to others?

I'm not sure, but Intense gives the best customer service and quickest ship time bar none. Intense answers your questions within minutes of your e-mail. ZZ has yet to respond to any of my e-mails, doesn't provide tracking numbers, and takes two weeks to get your mods.
Jack

I ordered from ZZp and before I ordered I had asked 10 million questions as I am in here! LOL!!! I had a response within minutes every time and I also got a tracking number. I decided to go with them cause the service was better and they were cheaper. As far as the fastest ship time they said I would have my stuff by wed and I ordered late last night. I guess I will see.

Autolite 104's????
What is this.

Colder spark plugs. If you ordered a 3.4 pulley, then you will want these plugs. They will help reduce the dreaded KR.
Jack

I heard from a few diff people that the NGK TR55's would help if tey were spaced at .55.

What e-mail address did you use? I was using zoomer@aol.com with no luck.
Jack
PS: The NGK's are also a good choice. Some say better than the $1.50 Autolites. I just don't know what part # to use for the NGK's.

Jack, you need THREE "O"s in zoomer. his is
ZOOOMER not ZOOMER. I made the same mistake a few times. Ive always gotten tracking numbers from ZZP and response emails. My parts always arrive within a week, Usually 3-4 days. Never had a problem with anything from them from parts to customer service. 3800 performance seems to have really good customer service also.

As for modular pulleys, Id say there probably isnt a whole lot of difference between them. The modular pulley that Intense sells is the one made by ZZP. ZZP's modular 3.4 pulley is on backorder so if intense has one get it there.

For plugs, I went with the NGK TR55IX plugs rather than the copper 104s since they will last longer than the 104s. I was going to go with GM Irridium plugs but my dealer was out and it was just as easy to order the NGks from ZZP while I was getting some other stuff. I know, I know, AdamS is gonna kill me

As for a TB spacer, for the price it couldnt hurt, if you ordered it, put it on. Terrapin, the one thing to watch out for is the spacer leaking. The spacer blocks the coolant from flowing through the TB and people have had some problems with leaking on the side that doesnt get the gasket (spacer to intake side) the spacer to TB side does get a gasket.

Mine after 20k miles is showing a few drips
but nothing major. I checked the bolts and the bottom two were a bit loose so that might have been my problem. Tighten them up and then check them regularly to make sure they dont loosen due to the heating/cooling.

well thats my buck 2.80 after taxes.

OK! I want to thank everyone with there help. This is all ordered and will be done this weekend or is already done.

NGK tr55's, 180T-stat, custom fenderwell intake, 9" K&N cone, 3.4 pulley, larger tensioner pulley, TB spacer, Ubend and resonator removed, 3" downpipe.

Does this all sound and look good for everyone? and am I forgetting anything? Thanks again for all your help!!!!

How about Iridium plugs? I just put those in my car a couple of months ago and I seem to like them. But the car is pretty much stock except for open cone.

Does anyone have any opinions on them?

Terrapin,

Good shopping looks good to me. Man I wish I had the cash to get all that. Enjoy your ride. I live vicariously through those who can mod their cars.

Enygma,

As for the irridium plugs are they solid or do they have irridium pieces on the electrodes? The problem with the Platinums is that they keep it cheaper by placing a small amount of platinum on the electrode and cathode to prevent erosion. By doing that those little metal pieces hold heat longer creating hot spots in your cylinder which could cause KR completely elimating the advantage of a colder ranged plug. If they are solid then they should be great.

I really didnt spend that much considering.
Ubend resonator removal=$50
180F T-stat=$12
NGK TR55 plugs=$9
TB spacer=$39
3.4 SC pulley=$59
K&N 9"cone=$50
Custom FWI=$10 (Had made for free by okc club gp president and had to buy 45 and 90 degree angle ABS thermal plastic street elbows and cone. He had it dynoed and has as much gain as the Wizair from ZZP and he is helping change the pulley for free.)
All this for a grand total of $230!!! Just shop around and check with people in your area. I have found all the people in all the GP clubs to be very helpful and extremely nice. I ordered my pulley and TB from ZZP. They are having a sale on alot of stuff right now!

That's good to hear. I've found the same to be pretty much true in just about any of our clubs. There's always someone willing to roll their sleeves up and get dirty working on someone else's car.

The only time that gets to be an issue (and I've seen this too) is when a club member shows up at meet after meet asking other members to do the work for them and then stands back and watches. That get's old real quick. I've wrenched on a lot of other members cars and am willing to spend all day helping if need be, provided I'm helping someone who's just as willing to sweat. That's when the fun starts!

Good luck,
Marc

Hi HercMan,

I'm not sure if they are solid or not. They are the AC-Delco Iridium plugs that are made by NGK. If that helps, then great. However, the boxes for the plugs are at home.

OK I got it all put on and it is running great. Major difference. I love it!!! We hooked up that palm pilt computer to my car and checked it all out. I only have 0.7 KR at the most and am not running too lean or too rich!!! I just have to get the down pipe removed for top end speed and it will all be perfect. Thank you all very much for all your help.

cool!!!!

HEY TERRAPINN just wondering, did you keep your stock mufflers ? did you notice incressed dronne in the cabin after U-bend & resonator delete?

I kept the stock mufflers and just took a trip from okc to dallas for NASCAR and did not notice a thing. Neither did the guy sitting in the back seat. I think it makes the exhaust sound a little better but nothing in the cabin. The resonator isnt very restrictive and only give about 2hp but I think it sounds better without it.

I would suggest the Ubend removal before doing any other mods though. It is so restrictive and doing other mods before this might cause KR. There is a local muffler shop here that will put on a 3"down pipe and U-bend removal for under $100. That alone will get you close to 15 hp without any other mods. It is also highly suggested before going with a 3.4 SC pulley. I was getting about 5* of KR at around 60mph before I replaced the down pipe. Now I have under 1* or none.