rojizostang

Those who have been helping me out with information and advice...I appreciate it. I thought I was ready to pull the trigger on the pulley swap, however I would like a little input from pretty much everyone interested or with experience.

Here are the numbers the truck made regarding boost on the dyno
80mm 9.5lbs
75mm 10.8 lbs
72mm tbd
70mm tbd

mods are the roush tvs 2300 with kooks 17/8 long tubes and off road x and full 3" exhaust. 47lbs injectors and stock fuel pump

I was all set to pick up a 72mm pulley and the supporting mods. After thinking about it and doing research, I don't think a 3mm reduction in pulley size will reap the performance increase I'm hoping for. (best so far is 11.98@114) I'm hoping to net 11.6-7's.

My current tuner says the motor can easily handle the 70mm pulley while remaining on 93 octane. He though it would probably make around 11.5lbs of boost...I think it will make at least 12 to 12.1

Is 12.1lbs of boost doable on my set up or am I inviting disaster? (again on 93 octane)

BadCon

How much timing are you running now?

rojizostang

It was fairly conservative before we went to the track for the datalogging, like around 14.5 total. He bumped it up a little, but it didn't make any difference in the et's. Part of the conversation that we had (about the 70mm pulley) was about being a little conservative with the timing, however we didn't talk about specific numbers.

I don't want of course to retard the timing to the point that the 70mm pulley is of no use. If that's the case then I would go with the 72 and leave the timing turned up a little....maybe...

it just seems that if i'm going to spend $700 for injectors, $125 for a pulley and then a fuel BAP or new fuel pump and a re-tune, that the 72 isn't enough to justify all the expense. it doesn't cost any more to do the 70, in theory any way.

BadCon

Can you run a track only tune? Its gonna be too much of a compromise to try and tune the 70mm pulley on 93, and I have a feeling your tuner is gonna just bleed off too much timing. You want to go fast, so why not develop a race gas tune? A can of Torco Accelerator or VP Octanium will raise 10 gallons of 93 to 100 octane. With 100 octane on board, you should be able to run max timing with that 72mm or even a 69mm pulley. Simply upping the timing 3 degrees on your current tune is good for 30hp.

rojizostang

yes, I would have to buy an ngauge or the mpvi2 to load the different tunes

I added some boostane professional last time out and they added a couple degrees of timing but it didn't result in anything positive

of course if I use a different tuner I can use the x4 and have a couple of different tunes for that. I've emailed Matt Alderman (this morning) about it to see what his thoughts are on it also. maybe i'm just making an assumption he would give me a tune with different options.
The positive with using the local guys is I don't have to supply any labor lol.
I haven't totally dismissed the idea of using id motorsports. I just didn't want to have to do all the labor associated with changing everything. I'm not sue I want to tackle removing the fuel tank.

BadAV

I can't specifically help with your setup, but a general rule of thumb on GM LS engines with a 2300 is you gain roughly 1 pound of boost for every 0.1" drop in pulley size. Your 80mm to 75 mm drop certainly didn't gain that much, however.

chimmike

do yourself a favor. Invest in a meth injection kit. you can use it at the track for a race-only tune.

w00t692

meth injection can eventually tear up the rotors in a supercharger, but it works SUPER good on a supercharger lol.

rojizostang

Just ordered the 72mm pulley. I think it will be good for maybe 11.4-5 lbs of boost. A little less than the rated psi because of the long tube cat delete exhaust.

Now if I can find a deal on injectors

blue5.0

Excited to see where you end up with your times. Us guys that want to build fast 12th gen trucks seem to be disappearing.