Just seeing who has this set up on there Supercharged S. I was looking at installing some gears like a set of 4.56 to help in the low end. Most of my driving is around town and i would like to get more pick up in the low end. I have a Ap1 sitting at 405whp. Whats your thoughts on these gears with my SC

 

Thats a lot of power for gears. 1st gear is already pretty useless due to traction at that level in my experience. Where is your vtec engagement point set to? Mine is set to 3500rpm and roll on throttle is great. never felt like I needed gears with this power.

 

Its set around 5300.. I had Jeff Evans tune it and he felt that was the best spot. Im still just trying to get a bit more down low. And was thinking the gears would help do this...

 

No, I think a re-tune with a proper vtec engagement would best do it for you. No wonder you feel like you need gears, your leaving a good 2000 rpm of trq band on the table. The only explanation for why he left it so high is your running a cat still and as a result no more power could be found that low.

 

^^ Agreed. Also, what exhaust are you running?

 

Retard your intake cam a couple degrees and pick up some of that much wanted torque.

 

Im running a T1R 70mm test pipe with T1R 70mm single catback. OEM header. I drove over 11hrs to have Jeff Evans tune it since i have heard nothing but great things about his tuning. I will have to send him a email.

Heres my dyno chart. Hows it look??

 

It's a bit weird he would put it so high. That being said u sure it's that high? Run more boost. That will fix the midrange hehe

 

Lude -- what is your AFR?

 

Its a little wavy but pretty linear/smooth, you can see a 5300rpm engagement, but its pretty smooth, he did a good job, but looks like if you had it come in right in the 4000rpm range you should be able to gain in that area up to stock engagement. Should be able to pick up a good 15wtrq and some hp.

How much boost you netting?

The other possibility here is that your 70mm exhaust is causing you to lose low end trq due to the valve overlap and lack of scavenging by the larger mm pipe, so in order to reduce loss, he set vtec higher. There is a good chance you would make a fatter power band with a 60mm exhaust. Most of us running this size see gains as low as 3500rpm, they may be sat the expense of a little up top. I'm sure sideways could elaborate more on scavenging and valve overlap and what happens with different size exhaust.

More boost may just be your best bet, or sideways cam keys as he chimed in with.