Close...San Joaquin County Fairgrounds swap meet.

Oh...I thought it was his 60' because of the 2.27 time on the second run--way high for an RT. 1.32 doesn't seem that outside of reality with AWD,

 

Alright, heading out to the track (Infineon) tomorrow night to get my "baseline" runs in...S.O.P. (seat of pants) tells me I should be starting out in the 12.8-9 range but would not be surprised to go quicker. I'll post up the results.

Then the over-drive pulleys and cam tests can begin!

 

Good luck Colby, I hope it runs better than you expect. Think about meeting up with us on the 19th Oct?

 

his 60 foots were 1.69s-1.71

at pinks this weekend nick set him up with another tune. ran 11.7@117 1.71 60 foot time. thats the 112hh still 9psi boost and race weight of 5400 pounds.

How much does your truck weigh anyway? your truck has to at least be in the mid 12s with all the stuff you have done.


A AWD tbss and a 2wd tahoe i think are only like 300 pounds difference in curb weight.

 

My new days off are Tue-Wed, so the Sundays no longer work...but at least I can make it to the weekly Wed drags, like today.

I'm at 5870# with a full tank but no me...so about 6050# race weight (with me in it).

I was able to make 4 runs today, and blew up the Auburn Pro Series on the 5th...got home courtesy of AAA.

We had about a 15-20mph head wind but good temps in the low, low 70s--very similar to my last time out. My best run was 12.707@105.91 with a 1.88 60'. The rest of the passes I had wheel spin on launch and had to let out and start again...each getting me a 2.13 or slower 60'. This is all with the exact same setup

To compare the difference at the track between my 347/mp112 & 383/122hh:

347 / MP112
60' = 1.915
330' = 5.365
1/8 = 8.279 @ 84.24
1000' = 10.814
1/4 = 12.985 @ 103.63

383 / 122HH
60' = 1.882
330' = 5.258
1/8 = 8.100 @ 86.23
1000' = 10.582
1/4 = 12.707 @ 105.91

Again I ask...where is the missing power? lol

AND, what is everyone's recommendation for a new posi...Eaton Tru-Trac?

 

man something is def up there.

wha ttrans are you runnign and what tire size???

my wifes bone stock trailblazer ss ran 13.3@103 but thing is i run 275 40 17s.

she had the same gearing as you tranny wise 1.00 3rd but 4.10 rear end gears. Dont know if your running 3.73 or not but your not going thru the traps at a good mph at all. Honestly i would look into a much shorter rear tire because that will make your truck run a lot better.

on my traiblazer ss i went from a 255 50 20 which is 30.4 tall ran a 12.8@109 2.2 60 foot then put on 275 40 17 drag rads the truck ran so much harder and ran a 11.9@112.9 with a 1.70 60 foot time.

if your doing the rear end geras id look into a much lower gear if you dont have 3.73 get em and if you do go with 4.10s. If your trapping 105 mph and looks like you have large tires your prob trapping like in 3rd at what 3800 rpms which is totally wrong for the 122 set up

if you can tell me what rear end gears your runing and also what tire size i can help you with that been down this road a lot from my s10 v8 days and now to my trialblazer ss days. You have the right engine combo just your tires/rear end gears prob hurting you a lot.


HERES some info for you bro
Lets say you have 3.42 gears redline is 6000 rpms
with 275 40 17 top speed of 3rd is 134 mph
with 305 35 18 top speed of 3rd is 138 mph
with 295 45 17 top speed of 3rd is 143 mph
with 345 35 18 top speed of 3rd is 143 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 150 mph (29 inch tall tire)


Lets say you have 3.73 gears redline is 6000 rpms
with 275 40 17 top speed of 3rd is 123 mph
with 305 35 18 top speed of 3rd is 126 mph
with 295 45 17 top speed of 3rd is 131 mph
with 345 35 18 top speed of 3rd is 131 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 138 mph (29 inch tall tire)


Now lets say you have 4.10s
with 275 40 17 top speed of 3rd is 112 mph
with 305 35 18 top speed of 3rd is 115 mph
with 295 45 17 top speed of 3rd is 120 mph
with 345 35 18 top speed of 3rd is 120 mph (28 inch tall tire)



Lets say you had a 285 50 20
3.23 on your tire 3rd at 5900 speed is 170mph with 275 40 17 top of 3rd at 5900 rpms 139.

3.73 on your tire 3rd at 5900 speed is 146mph with 275 40 17 top of 3rd at 5900 is 120.8

4.10 on your tire 3rd at 5900 speed is 133mph with 275 40 17 top of 3rd is 99.27.

heres more info

forgot 5900/mph in gears


3.23 with 275 40 17
1st at 5900 40 mph
2nd at 5900 75 mph
3rd at 5900 120 mph
4th at 5900 173 lol


275 40 17 with 3.73
1st at 5900 40 mph
2nd at 5900 74 mph
3rd at 5900 120
4th at 5900 173


275 40 17 with 410s
1st at 5900 35 mph
2nd at 5900 67 mph
3rd at 5900 109
4th at 5900 157

with that 122 you need to spin that sucker and with your tire you cant do that. off teh line i guarantee the 275 40 17 will give you high 1.6 to low 1.7s easy all day long.


What is your shift point rpm set at.

 

I'm good gear-wise...I'm running a 3.90 ratio that I installed with the now deceased Auburn Pro. My street tires are 275/45R20...a 29.7" tire. I have a set of M&H Racemaster drag radials in 275/50R17 which is a 28" and I'm sure that I would have run better with those. Note that a major point of this exercise was to compare my old set up with the new one and to do so I wanted as few other variables as possible. Some had stated above that dynos don't tell you much about your power--the track does. Well, so far the dyno and track results seem fairly in sync.

Anyway, seems like a 26" tire is really going a bit small, but I'm not opposed to running anything that works well. My shift points are set at 6k.

 

tires are to tall.


275 50 17 with your 3rd 1.0 and 3.90 gears top of 3rd at 6000 rpms is 127 mph way off of your 105 trap

lets say you trapped 107 mph. with those 275 50 17 your only going thru the lights at 5000 rpms bro. you need at least 5500 on that 122HH your running.

if your 3.90s are shot id step up to 4.10s.

4.10s with 275 50 17 and trap at 107 mph would be 5300 which would be better

now 3.90 gears with 275 40 17 and trapping 107 mph rpms would be 5450 and 4.10 gears with 275 40 17 trapping 107 mph rpms would be 5750 which would be perfect. just putting all the info on the table there. That 122 needs to be wound and you going thru the traps at 5000 rpms not doing it. Also 275 40 17 will save more than 10 pounds per tire which when applied to rotational weight will help a lot.

IM A BEliever in the mt drag rads 275 40 17 as you can see my wifes truck is stock only change is tires (well that and the custom front/rear coilovers I set up for weight transfer)
http://www.youtube.com/watch?v=6ya_6cxFN2g

 

I was just doing the same calculating and determined the same thing...a 26" tire would be ideal. I have the 275/40R17 MT DRs on my GTO and like them quite a bit.

But the issue here is that I don't believe that the truck should only be making 507/515, nor trapping at 105-107. I'm trying to get it up to the 600/600 that I was shooting for, and would expect that my traps would be in the 116-117 range. But even at that trap, the 275/40R17 will be at its sweet spot with 3.90 gears and shifting at 6000.

 

yah maybe can selection was bad and what heads are you running?


nick at newtech made a custom grind cam for my buddys tbss that was on pinks over the weekend and he dropped from i think 12.4 to 11.7 with a cam change and going from 8 to 9 psi thats it and he has the 112hh and awd that sucks a lot more power.

talk to nick at newtech hes my go to guy and did a bunch of the street racers gto vetts here at the street races and on norcal1320.com use him great results. Maybe he can set you up or try to figure out the problem. Also if you have a chance check out the meth injection your truck will run a lot better and prob get like 23 degrees timing out of it.