[rkm1003]

...finally after putting my combo togther, actually got the car on the track Friday night. Was really hot at first, high 90's, ran a couple 12.80's. Kept slinging alt/water pump belts(that's another issue). Ran a best of 12.51 @111 later in evening on last run. My problem is this - with my new cam, have very little vacuum fro brakes. By the time I get staged, I barely have enough brakes to hold the car at 1500 rpm. My 60' on last run was 1.98. I think the brake issue is hurting my 60' time. But I have been told that leaving at that rpm aint so bad, not so sure about that, I think car would launch better at higher rpm? Should I add a vacuum cannister to hold it at the line better, or go with manual brakes. I have disc/drum setup now. I want to keep it as stretable as possible, with 3-4 trips to track a year.

BTW, I sent Cliff a Q-jet for rebuild, with his carb, get brake issue fixed, and conditions right, I think I may break into the high 11's?

[66bonne]

Just a few comments: You might want to consider a line-loc to hold the car at the starting line. The vac can is a good idea too especially if you don't have enough vac while driving on the street.
Your 60' foot is a little soft and you can make some great gains by improvement here. What tires do you run at the track ? Are you spinning out of the hole ? Launching at 1500 is not necessarily a bad thing but it is something you will need to experiment with at the track [assuming you fix the braking situation]to see what your combo likes. We launch off of dead idle.
With a trap speed of 111 I would say that you will be in the 11s with just a little tweaking and some decent weather.
Congrats and have fun.
Jim

[71 Ventura II]

Running 111 MPH is a great place to start! With the cam your running you need a lot more than a 2800 converter to get the 60' down. Contrary to what seems logical converters generally fash harder when hit from a lower rpm like 1500-2000. Your MPH is good enough for high 11's the issue is getting it out of the hole quicker. Good luck! JD

[hal101]

hey got that firebird running great now

[grandville455]

Yeap get the 60 ft down and your there!!.FWIW. I ran 12.08 @ only 109.44... so 111 is there! Need to get car moving faster out of the hole

[rkm1003]

What tires do you run at the track ? Are you spinning out of the hole ?

Goodyear Eagle roundy round slicks. I got them for almost nothing, they are way better than my streets. Was spinning a little outta the hole, but to be honest, I was a little nervous. Last time I was down the track was a couple yaesr ago with 350/Th350 combo...and a best 0f 17et's, so this first couple runs really got my attention. Anyway, back the tires, had I been paying more attention, I would have dropped the air pressure in them, was running 16.5 psi, copuld have went lower I'm sure. If I decide to take the next step, will invest in a better tire.

You might want to consider a line-loc to hold the car at the starting line.

Have one. Used it for burnout only, held good for that, but the braking used to get staged used most of the vacuum, so don't think the line loc would hold anyway...besides, I thought that was "cheating"?

I am really leaning towards manual brakes, that with Cliff's Q-jet, better tires,

Here are couple vids from the track...

http://www.youtube.com/watch?v=PTXXN1QoJy0

http://www.youtube.com/watch?v=Eo3KLPa2pr0

[Brian Baker]

I've never been a proponent of vacuum cans, as they never seem to work as advertised. I've run hydraulic cams in the 238 @ .050" range, as well as a 270 solid roller, and never had any issue with not getting enough vacuum to operate the brakes properly, but then again my 79 T/A had the smaller booster on the master cylinder than probably what you have on your 1st gen. and the smaller boosters are apparently more efficient than the larger/older ones.

What you might want to try is decreasing the size of the vacuum hose from the booster to the intake manifold. This is an old street rodders trick and will provide a stronger signal to the booster than that of the larger OEM size hose. Keep the hose as short as possible too.

Another option is hydroboost...it operates off hydraulic pressure provided by the power steering pump. A friend of mine just finished a '75 T/A powered by a E-head 455 with a solid roller cam and he said it works great. To quote him, "It'll try to throw you out the windshield".

[60man]

"Eagle roundy round slicks" ??? What size tire & wheel combo ? Are they bias ply or radials ?? All slicks are not the same. Most radials like more air pressures than do bias tires..heck I even run 16.5 in my bias slicks..
..and yes...launching off idle or low rpms hits the converter/tires harder as Jim/66bonnie stated. I launch @ 1,500 and managae 1.46 60' with my barge. Your top end is there....get the 60' down and roll !!!
JMO

[rkm1003]

"Eagle roundy round slicks" ??? What size tire & wheel combo ? Are they bias ply or radials ??

tires are radials, 27" tall, 10" wide on 15x8 rims. I think a little less air would have helped a little. Have a dozen or so runs left in them, will play with air pressures next trip.

What you might want to try is decreasing the size of the vacuum hose from the booster to the intake manifold.

Like that idea, cheap and easy, may help..may not?

Thanx for all the input, looking forward to next trip to strip! Kel

[rkm1003]

First, tried the vacuum cannister to help brake issue........should have heeded all the info I got on Searchs here........no difference...almost no brakes.


...removed MC/booster and installed manual MC from Matt's Bowties......HUGE difference! A bonus with that MC was it had bleeder screws on the MC itself, never had one like that before, super easy. No more pulling wheels and craming head under wheel wells to bleed the system. Had some brakes lines laying around, plumbed it up, tore booster apart and "modified" acuator rod from it, brakes are really good now. Lineloc now holds super, smoked the hell outta tires in driveway, car stops like it should, and with hardly anymore effort than when pwr brakes were working. San Antonio has been having 100+ temps latley, but just can't wait for fall, so hope to load up and head there and see if I can get the Black Widow into the 11's??? Will post results. Kel

[screamingchief]

Glad you got it all worked out.

Cant tell you how many times I tried to tell some fella that manual disc/drum brakes are'nt all that bad in terms of pedal effort,but some folks just never believe till they get firsthand experience.

Hell,my '72 bird came from the factory with manual disc/drum brakes.

Stops fine.

Hydraulics are a wonderful thing.

If folks ever took apart their hydraulic floor jacks or engine hoist jacks and saw how small the piston is that lifts all that weight,they would be shocked I'm sure.

Yeah,proper cylinder bore sizing and pedal ratios need to be considered,but that stuff is relatively simple,and easy to figure out,and in some cases the OEM have already done that work for the end user.

Anyhow,welcome to the manual disc brake club,you'll never go back to vacuum assisted power brakes now.

[TIN TIGR]

amen chief..spread the gospel brother..power brakes on a racer/rod?..who ever heard of such a thing..heresy

[gto/gn]

Anytime I ever removed power brakes from a car and installed manual brakes I always took the rod going from the master cylinder to brake pedal and moved the mounting hole for that rod down as far as I could without binding anything. Usually about 1/2" to 3/4" . This gives you more leverage on the pedal and a big help in stopping power. This will help hold the car on the starting line..

[rkm1003]

Anyhow,welcome to the manual disc brake club,you'll never go back to vacuum assisted power brakes now.

You got that right Bret! Only cost me $45 for that lesson, cheaper than most other lessons.....BTW, have a Summit Vacuum cannister, like new condition for sale $25 shipped.

[Dragncar]

I think a 2800RPM stall is great for many Pontiacs.
I have run a 12.07 @105 with one. And I have a TCI 8" in the car right now and I want the 2800 back in it. But I bent all the vanes over backwards and it(GER 2800, they lied about the bells and whisles and now is out of business) is at the shop.
I am running a 11.23 @ 116-117mph right now with a 1.51 60 foot.
But the car has run a 11.16 @118,1.44 60 foot with that 2800RPM stall.
I am stuck to that seat with the 2800RPM converter.

[marks73ta]

Kel. I see you're running a 2004R. Do you have an aftermarket converter or a factory one? Listening to your runs I feel you need a good shift kit installed. the 3rd gear is sliding a lot into gear. And 2nd could be better. Is the converter a lock up? I had an '87 Turbo T that previous owner had installed a kit and an override switch to lock the converter up once into 2nd gear. It was a mid 12 second car. I would try the kit for sure and give some thought to the lock up. The only concern is the lock up clutch in the stock converters are known to be weak in higher torque motors that's why I asked if the converter was stock or? Mine was a stock turbo V6 Turbo T converter. I put alot of miles on it and it ran mid 12s so it held up to that. Mark L

[rkm1003]

Kel. I see you're running a 2004R. Do you have an aftermarket converter or a factory one?

10" from Art Carr.

Listening to your runs I feel you need a good shift kit installed.

Well sorta...when my buddy rebuilt the 400/200-4R, he called and got to talk to Art in person, seems they had mutal friends... anyway, Art sent rebuild/shift kit, TC and info. Car shifted really hard, just as it should have. I did some re-arranging of trax cooler and tranny temps got to 260, for a short time. After that, softer shifts came. Also, car will lurch between 3rd-4th when punching it on freeway. Randy called Art again, though he didn't talk to Art this time, Frank I think it was, said, the high temps "cooked the fluid". Clutchs are probably all glazed over. So yes, a fresh rebuild of tranny in in the near future. That with the new brakes, hoping for much better 60' times. BTW, TC is NOT Lockup. Thanx for the input, Kel

[cosgrove]

Originally Posted by gto/gn

Anytime I ever removed power brakes from a car and installed manual brakes I always took the rod going from the master cylinder to brake pedal and moved the mounting hole for that rod down as far as I could without binding anything. Usually about 1/2" to 3/4" . This gives you more leverage on the pedal and a big help in stopping power. This will help hold the car on the starting line..

It seems to me that is backward. Closer to the pivot is more leverage. Closer too the peddle is less leverage. Maybe I missed something.