olds 307 and 403

Mac, how tall or what size tires do you run?

Macadoo

Pressure gauge noted. Is it special gauge or just an oil gauge? Sunpro? Does it have to be permanent or can I pull it after some time? Not sure I have the room inside with the volt/oil pressure/ temp gauges.

307, my tires are 27 inches tall in the rear. They are 275/60r/15s. Just for kicks and giggles last night, I put my truck in 2nd gear and ran down the road at 3200 rpm. I caved after two minutes. I can't imagine doing that for an hour or more at a time.

Macadoo

I get it. Engine oil gauge doesn't read high enough. More like the TCI then...

http://www.summitracing.com/parts/tci-801100

oddball

Need a gauge with at least 350 PSI rating, plus fittings and HOSE to match. Barbs + hose clamp + typical hose = Very Bad Time.
Most gauges and setups are rated at 300 PSI which is a little marginal. A performance build can peak over 300 PSI when really getting on it, and that's a really bad time for a line or gauge to break.
Can't say I'm impressed by the line and fittings on that TCI unit. I wouldn't want to run that for more than a few moments just to check TV settings.

It's pretty normal to hook up a gauge with a long line (6' to 8') and just pull it out the side under the car, up and in through the window. Cruise around while holding the gauge to check it out. That's fine for testing.

If you want a permanent, then I'd say go with an electrical gauge.

JohnnyBs68S

Ditto on Joe's take on the 4th gear lockup and not needing a vacuum switch. I'm running a 3.90 rear gear and CK tuned the governor to not shift to 4th until the RPMs are plenty high that there is no worry about lugging the engine. As mentioned, when coasting down, if the car / RPMs get down anywhere close to idle speed, the trans will downshift to 3rd before even touching the gas. If I need to accelerate before it downshifts to third, as soon as I step on the gas, the TV cable tells the trans it needs to downshift. After city-driving it for 2 years, I've yet to encounter a situation where I wished I had a vacuum switch. If the engine ever felt like it was lugging when locked-up in 4th gear, a downshift to 3rd is only a small nudge on the gas pedal away. I've never given a vacuum switch a 2nd thought.


My hope is that after I rebuild my engine, my rear gear allows me to hit redline in 3rd about the time I cross the 1/4-mile mark (at least that's how I've planned it).


I used a "setup-and-break-in" kit from BowTie Overdrives that included a filter and pressure gauge to be used to for adjusting the TV cable. The gauge came with fittings and a hose long enough to dangle in through my vent window so I could read it while driving. When not using it (and before I disconnected it after I was happy w/ the setup and break-in), I kept it coiled up and tucked aside under the hood.

joe_padavano

How fast do you think you'll be going in the quarter? Third gear in the 200-4R is 1:1. Assuming 28" tall tires (275/60-15), at 100 MPH trap speed (roughly a high 13 sec ET), that's only about 4700 RPM in third. At 110 MPH (high 12s) that's still only 5200 RPM. Even 120 MPH (high 11s) is 5600 RPM. With 27" tall tires (255/60-15) those RPM numbers only go up about 5%. This also assumes a decent 60-ft time. Poor launches will drop the trap speed.

Macadoo

This one?
http://www.bowtieoverdrives.com/cata...php?ITEMID=572

How are their trannys?
http://www.bowtieoverdrives.com/cata....php?ITEMID=11

JohnnyBs68S

Yes, that's the kit. Now that I look at it, I forgot that it came w/ a temp gauge & sender, which I have yet to install.


I didn't use a BTO trans, I got mine from CK Performance (street/strip build, not the full billet one). I did use BTO's 1800 stall for now (stock 2bbl 350). It works great, shift to 2nd is plenty firm (hard to not bark the tires). I'm upgrading my drivetrain from back-to-front, did the rear end first (leaky axle seal), then the trans (leaked fluid and needed an OD gear after the rear gear change), last thing to do is rebuild the engine (shooting for around 400HP). Will get a different TC when that happens.


Joe, I used an old DOS-based "Cartest" simulator over 10 years ago when I was trying to decide what rear-gear to buy for my rear-end rebuild. Planning ahead, I set it up for the 200-4R ratios and my 245-60-14 tires (I think ~26" tall). Of the 3 choices available then from Richmond (3.42, 3.90 and 4.11), the 3.90 seemed to give me the best 1/4-mi traps with a ~400 HP engine without winding it really tight at the end. I don't remember the numbers OTOMH, but I was shooting for low 13s around 105-110. I may have mis-remembered the RPM at the traps it was estimating, but I do remember that was my goal. Maybe I was leaving myself some room for juice? Don't forget that the TC slips a few % too.