I would not run the underdrive pulleys.

If you insist on the S trim, and not the SC trim (which is designed for what you say you want), then just put your rev limiter (electronic I hope) at about 6000, and get a good tune.

BTW you could still blow the engine up first time out. Heck...you could blow the engine up without a blower. No matter what you do, thee is no guarantee of success.

 

I would not run the underdrive pulleys.

If you insist on the S trim, and not the SC trim (which is designed for what you say you want), then just put your rev limiter (electronic I hope) at about 6000, and get a good tune.

BTW you could still blow the engine up first time out. Heck...you could blow the engine up without a blower. No matter what you do, there is no guarantee of success.

 

what would be the downside to running the underdrive crank pulley?

 

I would have gone with the SC-trim kit. It's complete, basically a bolt on setup that works. Upgrades.....sure....do an impeller swap like most people do to the standard S-trim impeller for a couple hundred.....drop pulley sizes a time or two if you want, add a power pipe, etc.....

SC-trim = 8psi @ 7,000rpm
impeller upgrade $200+ = 4 more psi @ 7,000rpm
3.33" pulley swap $50 = 2 more psi @ 7,000rpm
3.125" pulley swap $50 = 2 more psi @ 7,000rpm
Powerpipe $250 = 2 more psi @ 7,000rpm

8 + 4 + 2 + 2 + 2 = 18psi without overspinning the blower (well just a few hundred rpm).

Tom Crews

 

I'm already starting out with what you would get if you send the SC-trim in for a GT impellar upgrade, only I'm not having to pay for an upgrade since I'm already starting out with the upgraded impeller. Seems like I just saved $200 to start out with?

 

Seems like you'll be spending more trying to make the "tuner kit" work in the first place to give you what you would have gotten in the "regular kit" (the full SC-trim).

You just mentioned you had a lack of upgradability with the SC-trim and I told you what upgrades were available.

Tom Crews

 

Seems like you'll be spending more trying to make the "tuner kit" work in the first place to give you what you would have gotten in the "regular kit" (the full SC-trim).

You just mentioned you had a lack of upgradability with the SC-trim and I told you what upgrades were available.

Tom Crews

S-trim tuner kit $2,495
39lb 03 Cobra injectors $100
90mm lightning maf $80
04 Aviator fuel pump $175
SCT reflash(its been done N/A) $175
Used powerpipe $150

I'll have $3175 in the complete setup, how much is an E-trim or SC-trim complete kit? I never even priced a complete kit because I was planning on running the 03 injectors which are plug-n-play with my 99 intake.

 

Piecing it all together is when you run into problems.

One thing I already noticed is that your 03 Cobra injectors will not work with the L-MAF...you need an 03 Cobra MAF. Remember, 39lb injectors vs. 42lb ones.

The SC would have been your best bet.
True, the S-trim is a higher starting point but you will spend more time and money "detuning" the S trim than just staring with the SC trim.

Good luck bro.

 

Piecing it all together is when you run into problems.

One thing I already noticed is that your 03 Cobra injectors will not work with the L-MAF...you need an 03 Cobra MAF. Remember, 39lb injectors vs. 42lb ones.

The SC would have been your best bet.
True, the S-trim is a higher starting point but you will spend more time and money "detuning" the S trim than just staring with the SC trim.

Good luck bro.

I was told a Lightning MAF meter was calibrated through the ECM like all the other ford meters. Pro-M and C&L are the only ones that calibrate the meter themselves, correct?

 

I was told a Lightning MAF meter was calibrated through the ECM like all the other ford meters. Pro-M and C&L are the only ones that calibrate the meter themselves, correct?

 

One thing I already noticed is that your 03 Cobra injectors will not work with the L-MAF...you need an 03 Cobra MAF. Remember, 39lb injectors vs. 42lb ones.

Actually, he could run that MAF with ANY size injectors. The key is that the proper changes are made in the EEC.

Ford MAF's are NOT sized to injectors or vice versa. I am running an 80mm LMAF on my Cobra and an '03 GT MAF on my Thunderbird. But, the EEC's have been massaged accordingly.

 

Actually, he could run that MAF with ANY size injectors. The key is that the proper changes are made in the EEC.

Ford MAF's are NOT sized to injectors or vice versa. I am running an 80mm LMAF on my Cobra and an '03 GT MAF on my Thunderbird. But, the EEC's have been massaged accordingly.

Thanks for confirming that. There is a lot of misinformation on the internet.

 

Now Im not expert on this but I dont see anything wrong in this. The S-trim should make less heat and be more efficient than the S/C and it will take less HP to spin it to 8psi?

Why are you guys being so ahrd on him?

 

what would be the downside to running the underdrive crank pulley?

I'm still trying to figure this out. People run larger crank pulleys on the 03 Cobra and other vehicles to make more boost, so what is the downside of running a smaller pulley to make less boost?

 

Now Im not expert on this but I dont see anything wrong in this. The S-trim should make less heat and be more efficient than the S/C and it will take less HP to spin it to 8psi?

Why are you guys being so ahrd on him?

He asked if he "thought this through" and we told him "no, you didn't". That's not being hard on him that's answering his question. He wants 8psi so he buys a 12psi setup. He also buys a tuner kit which requires him to piece together items and hope that he gets everything correct...again trying to make 8psi. But wait....Vortech sells a complete 8psi kit that's ready to bolt on and go.

He's planning on using underdrive pulleys hoping to reduce the boost by 4psi. Does he know it'll drop it this much? No...of course not. He's also underdriving his accessories systems at the same time he's putting more load (the blower power draw) on the same systems.

My thoughts on the subject are....don't ask for advice if you aren't going to take it. Don't ask for criticism if you aren't going to take it.

Tom Crews

 

why dont you measure the under drive pulley and then do the calclulations on the website (vortechs).

Personally your doing fine, i bought a used 01 GT kit that had a bad head unit (seal) and 'pieced' together my kit, dont get discouraged, it is worth it when its installed and tuned.

Knowing the impeller speed after the calculations you will know how high to sping ur motor to get 8psi. They may factor out (under drive pullies vs s-trim impeller)....take it slow and youll do fine, goodluck

feel free to pm me for any help/questions