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What pulley should I run?

T0pwater

T0pwater

New member
To start, I'll mention I've read the safely modding thread.

My hopes are to swap pulleys if possible before I get my Gen V. My setup is SD headers/corrected catted DP, 4" HAI w/ 9" cone, stock (non-ported) TB & gen 3, AL 605 (can change to 104 pending advice), 195 t-stat (don't want 180 - I'll wait to drop pulleys if I have to). When I swap to the gen V I'll be putting in a N* TB too.

What pulley do you think I can/should run with my above setup, considering that in the nearish future I'll be swapping to a Gen V + N*. I was thinking maybe a 3.5" and that way I can swap the pulley to the Gen V when I get it... I plan on scanning obviously, but I just wanted some preliminary advice on if its possible to run knock-free on a 3.5 yet.
 


Sorry, I forgot to add that I plan on getting a tuned PCM as well during this phase.

About the t-stat... how much knock does going from a 195 to a 180 really remove? I don't understand why 15* (if that) would make so much difference when you're talking about autoignition temperatures which are in the neighborhood of 536*F.

Has anyone tested how much knock is removed by going to a colder t-stat?
 
from what i understand, it's what is in the tune for the 180 tstat because you have the fans on sooner..etc
 
putting a colder tstat is an old school trick, haveing your fans turn on sooner and keep your temps around 180 can be helpful at killing some knock
 


You normally need a colder tstat with a tuned PCM, how much KR it eliminates? it depends on how aggressive the tune is. I get 0 KR at 85*C ECT and up to 2 KR past 90*C ECT with my current tune.

You also need to switch to AL104s when you drop pulley size and the N* TB won't help at this point, plus you would have to tune specifically for it. You may want to spend that cash in something more useful like a KR scanner.

If you're getting a Gen V assuming you get a tune, colder plugs and Tstat you could run a 3.5"
 
Yes it helps, although most of them are programmed for a basic 3.4 pulley setup. It will help by adding more timing and fuel at WOT and fixing some KR issues. Plus all the other stuff they advertise like higher shift points.
 
Thuglife2334 said:
it is that going to be a beatting on my stock tranny and engine.. .. and is intense a good PCM dealer!
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not unless you get a zzp tune. LOL, and intense is ok. seems to me that overkill and dhp are the best ones to get though. overkill takes forever for a response though...

have you read the 'safely modding your 3800' thread yet???
 


Read my thread?

Safely Modding Your 3800.

Get at it if you haven't, its in my signature.

To T0pwater...when you upgrade to a GenV unless you are cammed or have a full size intercooler...you are in no way needing anything more than a ported factory throttle body. As for the 180* T-Stat...it makes a huge difference after you get a tuned PCM since the fan turn on point is lower. Putting it in a stock car won't net anything besides lower crusing temps on the highway and crappier MPG's
 
My experience with my Gen V has been I needed to run a 3.6" with 15*-17* of timing. It really depends how much timing you are running. Stock timing=smaller pulley but I prefer timing.
 


You don't want to run anything less than 16*...why run less than stock? If you car can't take stock timing on the pulley your on...put on a bigger pulley.
 
bluegtp91 said:
To T0pwater...when you upgrade to a GenV unless you are cammed or have a full size intercooler...you are in no way needing anything more than a ported factory throttle body. As for the 180* T-Stat...it makes a huge difference after you get a tuned PCM since the fan turn on point is lower. Putting it in a stock car won't net anything besides lower crusing temps on the highway and crappier MPG's
Click to expand...

Ok, I should've given a little more background. I have no intention of stopping once I get to the 3.4/3.5 setup. I intend to go for full-size IC setup w/ rockers (1.9/1.95). No cam on the map for now. I figure why go for the ported gen 3 & TB when I'll want to upgrade to Gen V & N* later. So I figure, bypass the ported stock stuff and get the good stuff now to save money in the long run.

Also, just to clarify, will the crappy MPG's happen with the lower temps regardless, or does the tune take care of that?

To your other point, if I can run a 3.4" on a gen 3 and, for the same mods, run a 3.5" on a gen V, doesn't that mean the genV is flowing the same amount of air with a larger pulley, and thus robbing less power from the crank?

Juanmiguel said:
You normally need a colder tstat with a tuned PCM, how much KR it eliminates? it depends on how aggressive the tune is. I get 0 KR at 85*C ECT and up to 2 KR past 90*C ECT with my current tune.

You also need to switch to AL104s when you drop pulley size and the N* TB won't help at this point, plus you would have to tune specifically for it. You may want to spend that cash in something more useful like a KR scanner.

If you're getting a Gen V assuming you get a tune, colder plugs and Tstat you could run a 3.5"
Click to expand...

Now that I have my headers & intake, Aeroforce is next on the list.
 
T0pwater said:
Ok, I should've given a little more background. I have no intention of stopping once I get to the 3.4/3.5 setup. I intend to go for full-size IC setup w/ rockers (1.9/1.95). No cam on the map for now. I figure why go for the ported gen 3 & TB when I'll want to upgrade to Gen V & N* later. So I figure, bypass the ported stock stuff and get the good stuff now to save money in the long run.
Click to expand...

I understand...I'm just saying that to get potential out of the setup I wouldn't go little part by part...I'd wait and throw it all on at once.

T0pwater said:
Also, just to clarify, will the crappy MPG's happen with the lower temps regardless, or does the tune take care of that?
Click to expand...

The tune takes care of the fan turn on points for the 180* T-Stat to when the motor gets to 180* the fans kick on vs. the stock points...that is all that does...

T0pwater said:
To your other point, if I can run a 3.4" on a gen 3 and, for the same mods, run a 3.5" on a gen V, doesn't that mean the genV is flowing the same amount of air with a larger pulley, and thus robbing less power from the crank?
Click to expand...

oooooooooooooooooooooooohhh...I've typed this a few times...here goes.

The reason people upgrade from the GenIII to the GenV is a couple reasons...one being efficiency...you can get away with smaller pulleys on a GenIII but your yanking more power off of the motor to do so...where as the GenV...you can make the same power with a larger pulley and take less power off the motor to do so. The other reason being the rotors never flake apart from what I've seen...GM skimped on the GenIII's and it shows...the coating on the GenV's rotors are tits. The inlet to the GenV also doesn't "ramp" up like the GenIII's do...so you don't have to worry about the air having to run up to get to the rotors...guess you could call it an obstruction. Typical rule of thumb...I don't really say .2"...because some people will have different results. I will say that most 3.4"/3.25" setup GenIII cars are the same on GenV cars with a 3.6"/3.4" setup. You've just gotta mod more to drop pulleys on the GenV's. Also...according to Eaton...anything lower than a 2.8" on a GenV makes it spin WAY too much...causing a big break in inefficiency...only thing I would do...if you were GenIII and just kept running down in pulley sizes is this...when you get to a 2.55" on a GenIII, go to a 2.8" GenV...and be happy.

Hope this helps.
Click to expand...


^^I knew I typed that sometime lol....
 
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