Gears + converter = loss of power??
Thread Starter
Teching In
Joined: Apr 2003
Posts: 44
Likes: 0
From: Troy, Ohio
Gears + converter = loss of power?? Well, I am not very happy at all...for the money I spent on my new mods, it was almost like the only thing that got me better times was my Nittos. Anyway...I think I am losing power up top, the car lost mph. Anyone got any opinions.
Last years best
60' 2.065
1/8 8.71
1/8 mph 83.63
1/4 13.34
1/4 mph 106.21
Today....
60' 1.744
1/8 8.165
1/8 mph 83.99
1/4 12.83
1.4 mph 105.84
Yeah, I dropped .5 tenths....but with the addition of 3.42 gears, 3200 vigilante, and Nittos. Mid to low 12's sounds more like it.
I had 3 high 12 second runs, and seven 13 second runs. The car wasnt consistent at all...I could blow out first gear on the line and still run the same mph. The car doesnt make sense, I am not happy with these results at all. I have 3 auto tap logs of some of the runs...just need to get them posted so people can view them.
Last years best
60' 2.065
1/8 8.71
1/8 mph 83.63
1/4 13.34
1/4 mph 106.21
Today....
60' 1.744
1/8 8.165
1/8 mph 83.99
1/4 12.83
1.4 mph 105.84
Yeah, I dropped .5 tenths....but with the addition of 3.42 gears, 3200 vigilante, and Nittos. Mid to low 12's sounds more like it.
I had 3 high 12 second runs, and seven 13 second runs. The car wasnt consistent at all...I could blow out first gear on the line and still run the same mph. The car doesnt make sense, I am not happy with these results at all. I have 3 auto tap logs of some of the runs...just need to get them posted so people can view them.
Re: Gears + converter = loss of power?? I'd look at shift points as a possible issue. Converter + gears can equal whacked shifts. That would cost you mph. Also, inconsistency generally means spinning, unless you were systematically experimenting with your launch rpm.
Re: Gears + converter = loss of power?? what were you launching the car at? That converter likes to be stalled to around 1100 - 1500. You may need more tire than a nitto, and yeah check those shift points, and we will see what the ATAP says. You could have KR, be running rich/lean...there are many things to look at that can be adjusted. I can't see your sig right now so not sure if you have your mods listed, but I was running mid 12's with my stock converter and then when I installed my Vi3200 I went to low 12's, then got it restalled to 3600 and WOW, more difference than I thought it would be from the 3200. Better times and 60' by far. If you have the free stall upgrade still available I would take it up to 3600 
Hope you get it all figured out...GOOD LUCK!
Hope you get it all figured out...GOOD LUCK!
TECH Resident
Joined: Apr 2003
Posts: 859
Likes: 0
From: here, ny
Re: Gears + converter = loss of power?? i think the numbers look good... half a second off isn't bad... the mph didn't go up because there was nothing added to make HP... the car launched harder and made the time up there, but with no extra hp at the top, accelerated to the same speed...
Thread Starter
Teching In
Joined: Apr 2003
Posts: 44
Likes: 0
From: Troy, Ohio
Re: Gears + converter = loss of power?? Well, I bumped up my shift points and they are just about perfect, and not hitting the rev limiter. But what is wierd is that the last time I had low shift points, with the stock 2.73's and the stock converter, when I bumped them up, I picked up 2 tenths. This time I didnt gain anything. I need to get those ATap logs, I know on one run it was showing like 1.9 Knock retard. I will get my buddy to email them to me and then post them up. The car should just pull much harder with these mods, and to me it really doesnt. I was thinking about putting the stock stall back in and running it at the track, cause I didnt start having power problems till I got it back from the tranny shop.
Trending Topics
TECH Addict
Joined: Dec 2001
Posts: 2,850
Likes: 0
From: Plainville,MA
Re: Gears + converter = loss of power?? Are U sure U are suppose to be upping the shift points with more gear and a convertor?
When I swapped in my 3.42's from my 3.23's I dropped the shift points by 1 m.p.h on the 1-2 shift and the 2-3 shift to get the right shift points!
When I swapped in my 3.42's from my 3.23's I dropped the shift points by 1 m.p.h on the 1-2 shift and the 2-3 shift to get the right shift points!
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Re: Gears + converter = loss of power?? There are RPM shift points and there are MPH shift
points, if you don't make them both sensible you
could have some weirdness. Gears without correction
would indicate a higher MPH and maybe short-shift
you unless the MPH shiftpoint is raised or speedo
(gears/tires factors) corrected.
All of your gains were at the front, by the 1/8 mile
you were back where you started (MPH-wise). This is
strange, like you bogged on the 1-2 or got too low
in 2nd. Then you made up some time but not MPH.
Find what went lame between the 60' and 1/8 mile
points and you'll have your answer.
points, if you don't make them both sensible you
could have some weirdness. Gears without correction
would indicate a higher MPH and maybe short-shift
you unless the MPH shiftpoint is raised or speedo
(gears/tires factors) corrected.
All of your gains were at the front, by the 1/8 mile
you were back where you started (MPH-wise). This is
strange, like you bogged on the 1-2 or got too low
in 2nd. Then you made up some time but not MPH.
Find what went lame between the 60' and 1/8 mile
points and you'll have your answer.
Re: Gears + converter = loss of power?? How were the temps, humidity, etc... on the days you ran? It's pretty tough to compare when weather variables are not known. Weather can mean a lot.
Thread Starter
Teching In
Joined: Apr 2003
Posts: 44
Likes: 0
From: Troy, Ohio
Re: Gears + converter = loss of power?? The weather was almost identical on the two runs I posted. Both had low humidity and temps in the 60's. I used my HPP3 to adjust my shift points, and the car was shifting out of first and second at around 5700 rpm, so I bumped them to get them to shift out at around 6000, comparable to last years runs. I am actually going to re-install my stock converter and get some track numbers with that in. I think my Vig is slipping too much, I had more traction problems with just the gears. The car pulled harder with just the gears. Gonna do some experimenting with it.