Depending on your ideas for your car I think 4.10s can be too high.

Personally I will be going to a 3.73 or a 3.90 with my car, cause my setup is mainly based for twisties and/or road race stuff.

IMO for a Drag strip setup the 4.10 would be ideal.

 

Wildcat, my 1/4 mile time was 12.9 @ 111 mph. 60' time of 1.6. Elevation 1,200 ft at 102 degrees F. That's about what I've been running pretty consistently. What are your times running?

 

12.504 @ 111.96 with a 1.793 60ft on mickey thompson ET. Elevation of 519ft in 40 degree weather. That was at steele, al. At my hometown track in hsv, al (it's only an 8th mile), I can get easy 1.8 60ft on street tires. I'm guessing the gears would help me get in the 1.6 range.

What are your hp and tq figures? I'm surprised the elevation change of 700ft makes that big a difference in our times.

 

maybe the temp has some to do with that?

 

It could I guess, but it has absolutely no effect on my 8th mile times at my hometown track......I run 8.2 no matter.

 

1.6 with the ZF? Are you running slicks or just DRs?

 

how did u trap 111 with those mods?

 

Yeah, something don't add up. With a 1.6 60' time and 111mph trap speed, you should have been deep in the 12's.

 

That's what I'm getting at guys. I can't get a 60ft like that on street tires and we have one of the stickiest tracks there is. I'm launching at 4k with no spin on true street tires and getting 1.8 60ft. I could see 1.7s maybe with gears at my track, but not 1.6s

However, I'm also trapping 111 with the mods he has listed minus the rockers. But I did it at lower elevation. That's why I wanna hear what his hp and tq is, they should be slightly more than mine.

Maybe he granny shifts?

 

With a stock LT1 with bolt ons incl 4.09 gears i was trapping 110-112 mph shifting into 5th before the traps. I would reccomend 3.9 ratio if you have a stock redline and/or top end components (stock cam heads etc). you will trap higher and go through in 4th.

Sotp difference is VERY noticeable. it will feel like you gained 40-50 hp and your revs will climb higher. BUT you will then realize that it FEELS faster and being one gear higher say 4th you are now travelling just as fast as 3rd used to be. If you plan on using drag radials and are a drag person they can be helpful off the line.

Also remember for all you who try to top out your cars in 6th with 4.09s, your trans is living on the edge. the 6th gear synchro and reverse are shared so it is NOT very durable at all. I destroyed my zf-6.

6th gear was designed for FUEL ECONOMY ONLY. It was never intended for acceleration. even with 4.10s a .50 ratio for 6th gear is pathetic and is only stressing the components in the trans.

WIth my new 388 i put 3.73s back in it. for all around driveablility i love them much more than 4.09s. with 4.09s just crossing an intersection i would already be in 3rd gear. Sure i could rev it a bit higher and shift later but a stock Lt1 sounds labored over 3k rpm. However, with 4.09 my car still felt like it accelerated faster through the gears than with 3.73s and a stroker. Even my friends notice it doesn't have the punch. The G-tech however when i was running showed 113-115 mph on my fav strip of road. with the new motor its now reading 128- 131 mph. So there is a definitive difference in actual speed.

 

The temp might make some difference, but I'm running street tires (Firehawk). If I do basically a 1500 rpm launch with low psi on my tires, I can get out of the trap with little to no wheel spin. That is what got me the 1.6...I have only gotten a few good launches like that. Normally, I get 1.7s pretty consistently. However, once I'm up in the high rpms, I can't get traction shifting from 1st-2nd and 2nd-3rd (mabye I am granny shifting :-). I break traction at each of those shifts. So I know I'm losing at least a few tenths on the shifts. And yes, with the stock internals, I am having to shift into 5th to avoid redline.
With all of that I'm consistently trapping 109-111mph and 12.9-13.1 range. If I want to go faster, I'm going to have to do a head/cam install to push the rev limiter up to 6500 or so. I wish I had a dyno sheet, but I got stationed in Korea before I could get it on a dyno, so I'll have to wait until I get back. Does anyone have any guesses on the hp?

 

I just got Spicer 3.91's and will be going to the track to see a change. Only other change will be a B&M ripper shifter and a nicer day. Other than that its a stock LT1 6spd. I would hope 12.9x but doubt it in 80+ f heat.

 

with 111 mph traps thats around 330-340rwhp

 

give or take, thats about right! i have never seen a LT1 with bolt ons dyno those #'s or trap 111.

 

I trap 111.9 with 291rwhp, actually a little less because that was before my custom tune. We added about 15hp from 4k up with the tune. We didn't tune lower in the range. When I shift, it comes back to 4k. I have stock heads, stock cam, and stock gears and am running 12.5s. That's speed shifting all gears and never letting off the gas during shifts. I don't catch 2nd or 3rd for that matter. Of course, that's with sticky tires. Heck, I can barely catch 2nd on the street right now with my PS2s. I have factory gearing, the taller mickey thompsons actually hurts my gearing a little too. I made that pass losing to a friend in a DSM, he ran a 12.0.