skubydobdo

OK, my '65 98 is all tuned up and sounds and feels great when revved up in neutral. However, when in drive and going down the road, if i stomp on it I dont get close to those higher rpms, and the car seems sluggish because of it. I've got the stock 425/th400 combo. My buddy beat me from a 20 mph roll to about 75 in a car with 170 horsepower and even less torque. I also just read about how i can switch converter stall with this trans? Any ideas here for modifications would be great. I've got great pipes on this car and it sounds like an absolute beast, it talks the talk but i need it to walk the walk too. HA! Thanks

Oldsguy

So do you mean it boggs down with heavy acceleration? You may need to look at a carburetor rebuild.

skubydobdo

No, it doesnt bog down at all, just cant seem to get into the higher rpm range very easily at WOT when looking for that giddy-up.

Oldsguy

Have you ever owned/driven a heavy car like the 98 before? The acceleration isn't the same as you may expect, especially if you are comparing it to a car with a four cylinder or six cylinder engine, or even to a small block V8. But, to delve a little deeper. Is the transmission downshifting when you stomp on it? It should from a rolling start if it is already in second gear. Also, the third member ratio in a big car like a 98 is probably about 2.73:1, 98's were intended to provide smooth unnoticeable acceleration, they were a luxury car. Lots of variables to look at. Finally, what kind of "higher rpms" are you looking for and in what period of time? Does the car eventually top out at highway speeds say around 80 mph easily? (not encouraging anyone to break the law).

skubydobdo

Thanks for the quick reply. Yes, the transmission downshifts fine. I'm not expecting neck-snaping acceleration, but with some decent HP and huge torque figures I would like to feel it a little more. I just cant seem to get the engine into higher rpm before it shifts to the next gear.
This is my first "boat" car, haha. And my first 3-speed transmission. The engine runs so smooth and sounds so great I would like to use that higher rpm power. And yes, i can get it up to about 80, the fastest i've driven so far, dont need anything past that.

Oldsguy

You could expect that big block to run up to between 4,000 and 5,000 rpm considering it's age and stock condition, and it won't get there nearly as quickly as a smaller engine either. You didn't mention what car you were up against but just remember, it's a big heavy car. When you friend beats you in a race like you described just remind him you're driving a luxo-barge.

Olds64

Take your car on the highway up to 80 mph and see how much more the engine will give you. This is what those big cars are good at. You can be going down the highway at 90 mph and not even feel like you are moving.

skubydobdo

Gotcha. I guess what i'm asking is can I do anything to hold the gears longer to stay higher in the rpm range. Maybe do something with the switch-pitch on the trans?

88 coupe

Back to the basics:

What RPM are you looking for?

All this tells me is: He has a faster car, and you are comparing an apple to a tomato.

Your 98 came with a "switch pitch". If it is still there, and working properly, it does it automatically.

Does it already have a 4 barrel carb?

Get the distributor recurved by someone who knows what they are doing. Then lower the rear end ratio. Try driving it in second gear, at highway speeds, to get a "feel" for what you can expect. Once you have done that, contact Brian at: thetrickfamily@yahoo.com for advice, pricing, and availability.

You can shift it manually, but you'll need a tachometer to know when to shift.

Now for the important part:
If you were to take it to your local strip and time a few passes using different shift points, you would not find much difference between 3500-4500 RPM, and at much over 4500, your trap speeds would start going down.

Norm

z11375ss

I think you should put his car in your trunk and shut the lid, he'll never find it!

skubydobdo

^^^Haha good idea! I just picked up a snazzy retro-looking autometer tach to hook up, and try manually shifting a little bit, but nothing crazy. Thanks for the input guys, big help

RoaringRelic

Before you spend a lot of money try checking the stall speed. If you apply the brakes and step on the gas does the engine speed up? I don't mean try to win a burn out contest but it will either speed up or act like it is bogging down. If it doesn't speed up the roller clutch in the torque convertor is shot and you will need a new convertor. This is a common problem with the turbos and the only symptom is sluggish startup. Once you get to 30 MPH or so in first all is well???

spyke

Hey I'm feeling you bro. My cutlass is doing the same thing the only thing is my car sat down for about 3 months while I helped my son with his 70 cutlass before I stopped driving it I could be doing about 30mph and then get down on it and it would take off like a rocket , now it pull off fine sounds good idling but when rolling if I get down on it it acts like its starving for gas or something then I raise my foot and hit again and it will then react like I want it to. I put $30.00 worth of gas in it and drove about 10 miles when I got to my destination I had a 1/4 of a tank from having a 1/2 a tank before I could put 1/2 a tank in and go the same distance and would burn 1/2 that amount I keep getting suggestions, tune it up , change the fuel filter check for cracks in the distributor cap what could be the problem