Anybody on here ever back to back a 1.80 to a 1.69.I got a 1.69 and new combo seems like its about 5 hun slow in 60 ft but runs good mph for the et which I know it makes sense for difference in low gears. 4 link dragster 598 4 30 gear.1.11 60 4.86 et @ 143 mph. Just wondering what difference. I know there is a lot of variables in combos

quote:

Originally posted by 3628:
Anybody on here ever back to back a 1.80 to a 1.69.I got a 1.69 and new combo seems like its about 5 hun slow in 60 ft but runs good mph for the et which I know it makes sense for difference in low gears. 4 link dragster 598 4 30 gear.1.11 60 4.86 et @ 143 mph. Just wondering what difference. I know there is a lot of variables in combos

We have a 1.80 we'll trade ya, if yours is a decent brand.

Ours is a TSI 300m output shaft.

With shortages, might be an idea worth considering.

It always seemed to me that if one was to switch out a 1.80 to a 1.69 in your typical bracket type dragster, the idea would be to run a shorter gear at the rear to make up the difference in first gear, but then allow it to accelerate harder in high gear in a typical powerglide setup and run quicker to the 1/8 but likely run out of rpm by the 1/4 at that point. I remember doing the starting line gear ratio's one time and it was showing same ratio for two of the combo's to get a better idea.

1.80 w/ 4.30 and 34" tire = 7.74 SLR
1.69 w/ 4.30 and 34" tire = 7.27 SLR
1.69 w/ 4.56 and 34" tall = 7.71 SLR

quote:

Originally posted by NC3x58:
It always seemed to me that if one was to switch out a 1.80 to a 1.69 in your typical bracket type dragster, the idea would be to run a shorter gear at the rear to make up the difference in first gear, but then allow it to accelerate harder in high gear in a typical powerglide setup and run quicker to the 1/8 but likely run out of rpm by the 1/4 at that point. I remember doing the starting line gear ratio's one time and it was showing same ratio for two of the combo's to get a better idea.

1.80 w/ 4.30 and 34" tire = 7.74 SLR
1.69 w/ 4.30 and 34" tire = 7.27 SLR
1.69 w/ 4.56 and 34" tall = 7.71 SLR

That's where a converter that slips zero percent 7800 - 8000 rpm rules the game.

I'm waiting on banjo to make a 1/4 mile rip with his new converter. He'll be surprised how far it'll go now.

The 1.69 should soften hit and 60 foot. If you are allowed to run a grid ignition then I would run the 1.80 and tune with the Grid.

My classes here not allowed to run Grid ignition.

quote:

Originally posted by Curly1:
The 1.69 should soften hit and 60 foot. If you are allowed to run a grid ignition then I would run the 1.80 and tune with the Grid.

My classes here not allowed to run Grid ignition.

How?

With essentially the same starting line ratio.


1.80 w/ 4.30 and 34" tire = 7.74 SLR
1.69 w/ 4.30 and 34" tire = 7.27 SLR
1.69 w/ 4.56 and 34" tall = 7.71 SLR

Thanks, but i was wondering if anybody had back to back to know if I am in the ballpark on 60 since its been 10 yrs since I have owned a dragster and and its is almost the same exact car 2000 mullis The car I had earlier had a 4.10 and decent 555 and a 1.80 and my guess it would have run 4.91 probably @around 140 but it usually
1.06 1.07 60 I know I am kinda splitting atoms..I am not pulling any timing on the grid yet b

quote:

Originally posted by Curly1:
The 1.69 should soften hit and 60 foot. If you are allowed to run a grid ignition then I would run the 1.80 and tune with the Grid.

My classes here not allowed to run Grid ignition.

3628 this is correct. We back to backed a 1.65 to 1.80 x 4.10 at Bristol and it was .07 total in 1/8th going 4.7x there.

Thanks Scott

In my dragster i went from a 1.80 to a 1.69 and i only lost .02 in 60ft and .04 in 1/4 mile ET. This was with a 34.5 tire and 4.10 gears. It is a lot happier on the nitrous and i actually picked up when spraying.

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by Curly1:
The 1.69 should soften hit and 60 foot. If you are allowed to run a grid ignition then I would run the 1.80 and tune with the Grid.

My classes here not allowed to run Grid ignition.

How?

With essentially the same starting line ratio.


1.80 w/ 4.30 and 34" tire = 7.74 SLR
1.69 w/ 4.30 and 34" tire = 7.27 SLR
1.69 w/ 4.56 and 34" tall = 7.71 SLR

But it is not the same FINISH line ratio. Hello. With SAME rear gear changing from a 1.80 to 1.69 should soften hit some and slow 60 foot a little.

The original question was would a 1.69 slow 60 foot from a 1.80? I think the answer to his question is YES, but I do not know how much and I would like to know. He did not ask about changing rear gears to get same starting line ratio. The reason I have an interest in this thread is because I race Nostalgia stuff and can not run a grid to soften hit. So softening hit may be an advantage on some tracks here in my class. Also having more MPH than my opponent could be an advantage so I am interested in this subject. For the most part we choose rear gear based on desired RPM at finish line with tire we have and converter to help get it out of the hole. If my car runs .10 under index and the 1.69 killed .05 in 60 foot then that may be a good way to run the index and have more MPH than others with similar ET.

Yes, if you change rear gear to get same starting line ratio your 60 foot should be about the same. But your finish line RPM would not so it is not Apples to Apples and does not answer his question. If you change motors it would change things but what does that have to do with his question? Nothing. What does rear gear have to do with his question on 60 foot and .160 /1.80? Nothing.

Stay with us here. Does the 1.69 slow 60 foot and if so how much? Nothing about rear gear, tire, motor, weight, color of car Mothers maiden name, your favorite dog or anything else. All things being the same how much does TRANSMISSION gear ONLY change 60 foot?

Final gear is definitely a part of the adjustment.

I could've answered with a simple yes or no long ago.

But someone out there reading this, now comprehends the phenomenon.

Why.

Memorizing answers isn't learning.

There's a fundamental reason for every performance gain or loss.

Why

quote:

Originally posted by 3628:
Thanks, but i was wondering if anybody had back to back to know if I am in the ballpark on 60 since its been 10 yrs since I have owned a dragster and and its is almost the same exact car 2000 mullis The car I had earlier had a 4.10 and decent 555 and a 1.80 and my guess it would have run 4.91 probably @around 140 but it usually
1.06 1.07 60 I know I am kinda splitting atoms..I am not pulling any timing on the grid yet b

Yes Sir, I to would like to know that answer to, reason I am following this thread and other train wreck on 1.69 gear.

quote:

Originally posted by Curly1:

quote:

Originally posted by 3628:
Thanks, but i was wondering if anybody had back to back to know if I am in the ballpark on 60 since its been 10 yrs since I have owned a dragster and and its is almost the same exact car 2000 mullis The car I had earlier had a 4.10 and decent 555 and a 1.80 and my guess it would have run 4.91 probably @around 140 but it usually
1.06 1.07 60 I know I am kinda splitting atoms..I am not pulling any timing on the grid yet b

Yes Sir, I to would like to know that answer to, reason I am following this thread and other train wreck on 1.69 gear.

Highest average torque at the back tire from A to B wins.

A. Starting line B. 60ft

All things equal (traction)

quote:

In my dragster i went from a 1.80 to a 1.69 and i only lost .02 in 60ft and .04 in 1/4 mile ET. This was with a 34.5 tire and 4.10 gears. It is a lot happier on the nitrous and i actually picked up when spraying

this is the answer,if you add load without adding power you will slow down

I am going to put the motor in my 3200 pound nova..I was thinking high gear only since it has ladder bars ..but I might put a 1.69 in it from what I'm learning.....Scott gave me the answer I wanted 7 hun slow down in the 1/8 makes me think my stuff isn't broke