I have 3 boost settings..
The most that I ran with is the 2nd setting.. @10psi with around 650rwhp.. with my 4.10's I was spinning for about 40 yards off the line with all 4 tires..
I was told to buy all 4 slicks and wouldnt spin at all at any setting.. (3rd setting 750rwhp + 75hp of nos)
thats why I want to run as fast as possible in the 1/8th by switching gears.. 4.88 or 5.13's? Or is it too much?

 

That's way too much gear for 28" tires.

You need to do more than just slicks, you need suspension stuff also. My front coilovers help, or at least use straps if you don't care about ride quality. Good shocks for the rear and traction bars also help.

 

I have them already my man!
Your coilover setup which I love btw, caltracs and RS9000's in the rear as you told me too..

 

Perfect!

Any launch videos?

 

Maybe if you stayed with a 32 inch tall slick. By going down to a 28 inch slick you effectively turned your 4.10 gear into a 4.56.

 

When my truck was running 10.90's to 11.20's around 122 mph in the 1/4 I was running a 4l80e and a 4.56 gear on 29" tall tires. If I remember right, if I didn't lock the converter it was going through the traps around 6800-6900 rpm. With the converter locked it would go through around 6500.

I know you are talking about 1/8 mile ****, but the above can give you a pretty good idea of what you are looking at gear/converter/tire/mph wise.

 

One more thing I'd like to add to the above post (and I'm still not 100% convinced I didn't get fucked).

when I had the rear out and gutted to weld on the new shock mounts and all that ****, the shop (I have always used and have been very happy with) straightened the housing and installed the brand new 4.56 gears for me. I'm pretty sure they were an aftermarket gear set. During the first 10 passes or so I was getting the truck dialed in and ready for the "set on kill" pulley set up and fuel system. So when I saw that I was damn near running out of gear with the 4.56j's, I had the shop pull them out and install an OEM set of 4.10's.

I had every intention of selling the 4.56's cause they only had like 5-10 passes on them (no trans brake) and zero street miles. Anyway, when I went to go pick the rear back up, the dude at the shop showed me a burned up fucked up looking 4.56 ring and pinion sitting on the table. He said it was mine and it would have likely broke pretty soon. His opinion was "too much weight and too much power". He tossed them in the trash and away I went.

Later on, the more I thought about it, there was a small voice in the back of my head telling me that he was lying to be able to keep a practically new 4.56 set.

I never made a fuss about it. The dude has always treated my right in the past and it only lost me $100 from being able to sell them. So no big deal. \

The 4.10 set up that went back in took a massive beating at the track and never had an issue. I've always been a fan of OEM ring/pinion sets if the ratio is available. They always seem stronger than the aftermarket pieces.......they are more pricey though.

 

Sorry to hear about the guy who took your 4.56's from you.. that pisses me off.. I just had a shop switching the injectors in my buddies twin turbo 408 from 95lbs to 130lbs and they kept the injectors and didnt give them baxk... As well as a turbonetic that they "put apart and used it to fix the other 2 in the truck" so everything disappeared..

Back to gears.. so with 29" tires and 4.56 makes me think i can keep my current setup 4.10's for the 1/4 of mile and have the other setup for the 1/8th of mile with a set of 4.88 with my 28" tires.. I dont think I would run out of gear in such a short race..
Do you think I need to retune from 4.10-32" tires to 4.88-28" tires?
Thanks man!

 

As a general statement, a gear ratio/tire size change shouldn't need a "retune".

However, if you are running an electronic transmission you should make those changes in the tune so as not to **** up the shift tables and speedo. I don't consider that a "retune" but some might.

 

32/4.10 @ 50 mph with zero driveline slip would be 2153 rpm.

28/4.88 @ 50 mph with zero driveline slip would be 2929 rpm.

So yeah, if you're using an electronic trans.........that absolutely needs to be addressed. Huge change there.