Closer ratios and a 3.5 final drive and I'd agree.1972ho wrote: ↑Sat May 27, 2023 10:32 pm )
Get yourself one of these automatic transmission and that 283 will feel like it has a big block in it.
First:
4.56
4.03
Second:
2.97
2.36
Third:
2.08
1.53
Fourth:
1.69
1.15
Fifth:
1.27
0.85
Sixth:
1.00
0.67
Seventh:
0.85
N/A
Eighth
0.65
N/A
Reverse:
3.82
3.06
Axle ratio:
2.41 (Stingray / Z06)
2.73 (Stingray with Z51)
2.56 (std.)
2.73 (with Z51)
Best Exhaust To Add Torque To 283?
Moderator: Team
Re: Best Exhaust To Add Torque To 283?
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
Re: Best Exhaust To Add Torque To 283?
I'm normally one to derail threads into what I've just learned myself, but I'm reasonably sure that a 6/8spd auto swap is outside the scope of this thread about finding a bit more low-mid pep via exhaust changes...
That said, what would you use to control it? Would you mess with the ignition for torque reduction on shifts? With lockup available in all forward gears, could a carby engine with a medium size cam even operate where this gearbox could push it in cruising?
That said, what would you use to control it? Would you mess with the ignition for torque reduction on shifts? With lockup available in all forward gears, could a carby engine with a medium size cam even operate where this gearbox could push it in cruising?
Re: Best Exhaust To Add Torque To 283?
One thing that could be changed to make this car accelerate faster is increasing the rear gear ratio.
A 20% increase in axle ratio will make it act and feel like the engine is now 20% BIGGER cid.
eg: the 283 will have the net axle torque output as if the car now has a 340 CID engine in it.
Change the rear axle ratio from 3.89 to 4.57 (9" axle)
It will GLH. The Overdrive in that trans will really tame a racey rear gear for cruising.. A lil 283 with a cam wants GEARZ..
If the rear tires are taller than 26" I would increase the gearz even further.
What is the rear tire true diameter?
How much does this car weight? all in with driver?
A 20% increase in axle ratio will make it act and feel like the engine is now 20% BIGGER cid.
eg: the 283 will have the net axle torque output as if the car now has a 340 CID engine in it.
Change the rear axle ratio from 3.89 to 4.57 (9" axle)
It will GLH. The Overdrive in that trans will really tame a racey rear gear for cruising.. A lil 283 with a cam wants GEARZ..
If the rear tires are taller than 26" I would increase the gearz even further.
What is the rear tire true diameter?
How much does this car weight? all in with driver?
Re: Best Exhaust To Add Torque To 283?
This was mentioned previously by another member but the importance may have slipped by.
Did you or your builder/mechanic check for true TDC and correct TDC on the balancer/Timing tab.
On one 350 I built with factory balancer and timing tab I found that the TDC mark was off by 4 degrees.
Had to move the timing tab.
This can make a BIG difference if like mine the ignition timing is always a bit retarded from spec.
This is something you want to verify.
Did you or your builder/mechanic check for true TDC and correct TDC on the balancer/Timing tab.
On one 350 I built with factory balancer and timing tab I found that the TDC mark was off by 4 degrees.
Had to move the timing tab.
This can make a BIG difference if like mine the ignition timing is always a bit retarded from spec.
This is something you want to verify.
Re: Best Exhaust To Add Torque To 283?
I appreciate the suggestions. With the 283 kept for nostalgic reasons, I’m clearly working with a few compromises.
Since it sees lots of highway rallys and 80 mph interstate time, for now the 3.89s are the most rear gear it will see. Thankfully it’s a Quick Performance 9 inch so I have the option of going higher gearing in the future.
The newer 8 and 10 speed automatics are a cool idea for small cubes, but as an old Turbo Buick guy the 200-4R was the perfect choice, with 2.74 first and .67 overdrive. 1-2 gear spacing is good, it fits well, is easily controlled with TV cable, has less drivetrain loss compared to a modern trans like the 6L80E, and I didn’t have to change the driveshaft. And it’s still under 3000 at 80 mph.
Verifying the exact timing was a great suggestion. Mechanic thinks it’s dead nuts now, but when I do headers in Omaha I’ll have a more performance oriented shop check TDC when we do headers.
Regarding the carb mods, its AVS2’s annular boosters make it quite responsive now with more timing and 4 hole spacer. I’ll look for the Vizard articles, and ask dyno guy about carb mods.
Thanks all.
Since it sees lots of highway rallys and 80 mph interstate time, for now the 3.89s are the most rear gear it will see. Thankfully it’s a Quick Performance 9 inch so I have the option of going higher gearing in the future.
The newer 8 and 10 speed automatics are a cool idea for small cubes, but as an old Turbo Buick guy the 200-4R was the perfect choice, with 2.74 first and .67 overdrive. 1-2 gear spacing is good, it fits well, is easily controlled with TV cable, has less drivetrain loss compared to a modern trans like the 6L80E, and I didn’t have to change the driveshaft. And it’s still under 3000 at 80 mph.
Verifying the exact timing was a great suggestion. Mechanic thinks it’s dead nuts now, but when I do headers in Omaha I’ll have a more performance oriented shop check TDC when we do headers.
Regarding the carb mods, its AVS2’s annular boosters make it quite responsive now with more timing and 4 hole spacer. I’ll look for the Vizard articles, and ask dyno guy about carb mods.
Thanks all.
Re: Best Exhaust To Add Torque To 283?
Have you considered a Gear Vendors overdrive?
Maybe it was suggested already and I may have missed it.
We hooked one up to the Chevelle back in the day (on the back of a TH350) when they were in their infancy. The electronics back then were a little ungainly (as in not un-obtainable) but I see that today's offerings are very slick. It was a pretty cool piece all the same.
Just a thought.
Kevin
Re: Best Exhaust To Add Torque To 283?
At 80 mph the engine rpm will still be under 3000 rpm cruise in overdrive (26" tire) very reasonable for a cammed 283.. 4.30:1 rear gears is none too much.