I own a 1990 Firebird Formula with the stock 305 T.B.I. engine and automatic transmission. I recently made a few upgrades. I changed the stock rear-end to a 3.42 positive traction. I replaced the stock air cleaner to a K&N open element. I installed a MSD blaster coil and MSD plug wires. I used NGK V-Power plugs.

My problem is take-off power and initial throttle response. I have a tremendous amount of 'midrange' power. But it seems like it takes forever to get to 25 MPH. I realize that I don't have a 350, but I have owned 6-cylinders that have more throttle response than my Formula.

I know this is logically impossible, but it seems like I had more initial power before I did all of the upgrades.

If anyone has any suggestions (other than installing a 350), please let me know.

 

Looking at your topic I would have said gears but youve got that covered. Maybee you have something wrong. Check out all your tune-up stuff and especially the timing having it off could kill bottom end power. If everything is in check and you have an automatic looki into a better converter. The corvette one is pretty cheap and much better than stock I saw someone on here mention$85 + a small core charge. Do a search in the tranny/drivetrain forum.

 

You need a torque convertor. I'd go with about 2k - 2.4k stall speed lockup. Yank and Vigilante make the best convertors at 9.5", allowing the engine to spin up faster, putting more power to the ground, but they are very $$$. expect to lose 2- 6 tenths in the quarter with that mod.

 

why would you loose 2-6 tenths?? Oh-well I have a 5spd so I don't have to worry about that. As for the topic, I just installed some march underdrive pulleys and I think I take off a little bit quicker. Also, some one correct me if im wrong but wouldn't putting a lighter flywheel make it rev quicker their for makeing it take off better????? I thought I remember hearing someone say that.

 

Yes, putting a lighter flywheel will do that, as would removing the smog pump from the serp belt, adding underdrive pulleys. Anything you can do to take strain/weight off of your crankshaft will ease your engine's ability to rev. Lightweight roller rocker arms, etc do the same, and send more power to the wheels due to less drain from the drivetrain.

Though not as much as a Vigilante or Yank Converter. A higher stall convertor stalls the engine up more before it engages. The fact that it's lighter also lets the engine rev a little faster than the stock convertor. It really increases the efficiency of the auto transmission. Most people who drag race use high stall automatics for this reason over a stick. They are very very consistant and fast out of the hole. Personally I'd still rather have a 6-speed

If you have more questions look up Pro-Built Automatics under transmission forum. He usually posts his company phone number, and will explain how the transmission, torque convertor and shift kits work. I know I learned a lot when I spoke with him.

 

I think he meant you would drop 2-6......like if you had 15.6 and went 15 flat, you lost .6....even though most would say "gained" (speed)

 

Ya that's what I meant. Thanks Vic.

 

A stall is what you need
When I did the 3.42 swap I had the same problem

 

Do you have a different TC, ZRated? I have the same gear ratio you do, and does seem to take a little longer than I want it to to get out the hole (best 60'= 2.25).

Edit: I believe the stock stall speed is 1200

 

I was thinking the stock stall is 1800, I thought I read that some were.....isn't a good rule of thumb : put your left foot on the brake, and gas it, were the tires break free (it you have enough power), thats your stall, of course I don't remember who told me this....so it might all be B.S.

 

My tires break loose well before 1800 rpms. Stall isn't a constant. If you buy a "2400 stall TC" that doesn't mean your stall is 2400. It is dependant on what kind of torque your engine is making at a certain engine speed. 2400 is an average. Might be a little more or less.

 

that makes perfect sense.......I need to start thinking again, LOL