supporting mods for a 3.4 s/c pulley

**BADAZGTP** · 05-27-2008

I am asking a question for a friend. He has a stock GTP and wants to run a 3.4" pulley. What exact mods would he need to support this. I just want to make sure I am telling him the right stuff. Cold air intake, catback exhaust, PCM, colder plugs and thermostat. Do I have it right or am I missing anything? Don't want to see him end up with alot of KR. Tryin g to remember everything I did. It's been awhile.

**Sabrewings** · 05-28-2008

Down pipe.

**JoshMcMadMac** · 05-28-2008

The cat-back is not necessary...the exhaust bottle-neck in north of that. U-Bend delete and down-pipe are a good start. That with the PCM, intake, thermostat, and plugs that you mentioned should make it safe.

**Bio248** · 05-28-2008

intake, 3" downpipe, u-bend delete, 180* thermo, colder plugs, and a lot of luck.

even with my mods (but running untuned) im getting around 4* of knock sometimes. scan, scan, scan.

**Going Too Phast** · 05-29-2008

Not the almighty 3.4 pulley. Only run as small a pulley as you can safely. A lot of people struggle to run a 3.4. To be safe, this is what I'd suggest:
#1 Maintenance! (fuel filter, ignition, etc.) Make sure that thing runs perfect before modding.
Downpipe
PCM (seems like people with ZZP PCMs have more KR issues, but I may be imagining things...)
Intake
180* tstat
Autolite 104 plugs
Plog
Rockers
...and scan, scan, scan. If you get KR, go to a larger pulley size unless you want to dump more money into it for mods. If there are plans for 12 second 1/4 times in the future, and you have the money, you may be better off with headers.

The old recipe of downpipe, intake, and a PCM hasn't worked in 99% of the cases I've seen for a 3.4 to run KR free.

**FastKatt** · 05-29-2008

Scanner
/thread

Going Too Phast just about said it all...
Plog = waste of money IMHO, mod bug will take you to the headers b4 you're said and done
Don't get rockers if you plan on a CAM in the future, or you're wasting $$$
Scanner, Headers w/Downpipe, Intake, 180* Tstat, Cooler plugs (1 heat range), Premium fuel (93 Octane), Custom Tune > Box Tune

**kyle99gtp** · 05-29-2008

3.4 sucks, i hate mine, and its a press on so im stuck with it. when i have more money im moving up to a mps 3.8/3.6/3.4.

i still hvae 6 degrees of (untuned, biggest problem) knock with all my supporting stuff.

**04monte** · 05-30-2008

Make sure he scans first. On 1.8rr, plog, 3 in DP, rear ported mani, 180 t stat, autolite 104's I run a 3.3 with no kr. (plog started leaking at the crossover and is getting blips because of fueling issues) But I also have an hptuners so I can tune the fueling and timing.

**BADAZGTP** · 05-30-2008

Thanks for everyones input. I'll pass it on to him and hopefully he'll understand that he can't just trow somwthing like that on without support of other mods.

**FastKatt** · 05-31-2008

Why doesn't he join the site himself?

**BADAZGTP** · 05-31-2008

Originally Posted by FastKatt

Why doesn't he join the site himself?

I told him about the site. He is new to cardomain and the 3800 world. Waiting to hear back from him to see what he's going to do. Told him this was the place to be. You can lead a horse to water, but you can't make him drink.

**AR15 guy** · 06-03-2008

I had plans for a 3.4 pulley but maybe I should start with a 3.5? I was going to with the modular setup so it wouldn't be hard to switch back and forth.

I am doing pacesetter coated headers and a cai of some sort first. Could I run a 3.5 with no problems on stock tune with a 180 stat and colder plugs?

**ryangtp89** · 06-03-2008

Originally Posted by AR15 guy

I had plans for a 3.4 pulley but maybe I should start with a 3.5? I was going to with the modular setup so it wouldn't be hard to switch back and forth.

I am doing pacesetter coated headers and a cai of some sort first. Could I run a 3.5 with no problems on stock tune with a 180 stat and colder plugs?

you gotta upgrade your pcm, i have a zzp 1.0 pcm, but i been hearing alot of bad things about their pcm's l8tly, but who knows, if i where you i would go with overkillmotorsports

**AR15 guy** · 06-03-2008

I have a guy locally that can and has tuned GTP's. I will be taking it to him when I do any kind of serious mod.

**BADAZGTP** · 06-03-2008

It's good to have someone that can do that.

**AR15 guy** · 06-03-2008

That being said should I start off with a 3.5 or go straight to a 3.4?

**Reptile** · 06-03-2008

I'd say a ported blower couldn't hurt.

TDCRacing · 06-03-2008

Talk to reptile about that.....He does awesome work. Hopefully i will be posting up some pics of my blower that brian did.

go ahead and get it polished while ur at it(also done by brian)...I did and trust me i am not lookin back

**AR15 guy** · 06-03-2008

I would get mine ported but I can't afford any down time. Which is one reason I was looking at ZZP. But I have heard a lot of bad stuff about zzp lately.