[garrity455]

Darby, I hope you make Norwalk some year, it is just amazing for any fan of Pontiacs.

Formula, it is the cheapest holley regulator, so it could possibly be a restriction as well. I tried the bigger robbmc regulator, but blew the diaphragm twice. Last time was at the track, so we swapped this in. Haven't updated it since.

As for cruising at 75, that was with my old 3.23 gear. Last year the new converted and gear went in at the same time after I blew the rear. In hindsight, if I had to do over again, I would have stayed with the 3.23 gear. I now only cruise at 70 at 3000 rpm.

Here are some short videos from today.

Car cruising at 35 mph at 1620 rpm.
http://www.youtube.com/watch?v=bM_0O...e_gdata_player

Car cruising at 70.
http://www.youtube.com/watch?v=v5bgG...e_gdata_player

Shaker shaking at light.
http://www.youtube.com/watch?v=F3hvP...e_gdata_player

I do admit it is odd to run 11.43 and never hit 115.
But all my combos have always ran better ET than mph... Guess I am getting used to it, although I do keep making changes.

Maybe one day it will balance out

Although aren't they calculators that say what a car should run?
I assume I am close to proper ET for 550 hp, 3800 lbs, 3.42 gear.
Maybe not mph, but close in ET?

[grandville455]

Nice video's mike, Wallace racing has the calc u want , the one's with the hp correction are going to be the most accurate, cause it factors in weather also..The convertor is working well at cruising for you. The conti's are tight! I just think for all out racing is where its too much, for your current setup, but nothing wrong with running mid 11's

http://www.wallaceracing.com/et-correction.php

[garrity455]

Thanks guys.

I think I am going to put an end to this original thread for now.

I am going to just race the car a bit, and stop trying changes for a few months.

We did get out to the event this past weekend and ran a pass on the 750 and then changed over to the 850. I have a picture of the times.

Ran an 11.60 at 114.52 with the 750, and a best run of 11.579 at 114.52 with the 850.

Although it did run a new best 60' ever of 1.535!

Here is a shot of the runs for the day. I think I will just enjoy it for a few months and get through Norwalk, and then take it from there.

Maybe if I cut over to a Torker II intake, and tightened up the converter some it would run 1.6s, and 118. But who knows.

Oh one interesting thing. We finally recorded a clean run in drive and found that in drive it shifts out of first at 4300, and out of second at 5000.

Crazy that two weeks ago we ran an 11.52 with 5300/5300 shifts and
and 11.56 with 4300/5000 shifts.

Thanks,
Mike

[ponjohn]

Mike-

These combos make so much tque that a few hundred rpm doesn't make much difference if any.

Did you run electric through mechanical pump this time out?

John

[garrity455]

Hey John.

Yes, I knew a couple hundred RPM wouldn't matter, I was just surprised I could drop the first shift by 1000 RPM, and the second by 300 RPM and still change less than .05.

Yes, this was still running the electric through the mechanical, just the carb swap was new.

I do intent to get solid video of the fuel PSI gauge for an entire run and verify I am not getting pressure drop. If I do find that I am, I will continue to change fuel system parts until I can be sure I am not having psi drop.

Thanks,
Mike

[Cliff R]

"Although it did run a new best 60' ever of 1.535!"

Not bad for right off the bench here right onto your engine! I'll tell Ray he did a good job on it!

My engine LOVES that carb as well, and it runs really hard in 60' and in the mid-range.

I'd use it more, but the 1977 Pontiac Q-jet outruns it on top end on the dual plane intakes, and doesn't use quite as much fuel for "normal" driving......Cliff

[garrity455]

Hey guys, just wanted to post another update on this old topic.

We had the car out at Norwalk this past weekend. We were in the photo shoot and did some testing and tuning.

First runs were 11.7s at 112 to 113. Which is about what we expected in the 90+ degree heat.

We tried our little air filter, and then no air filter at all with no change.

But then we took the shaker off of the car, and ran a bigger k&n filter with filter lid. We picked up 1.5 mph. We went from 113 to 114.5. We backed it up with a few runs, put the shaker back on, with and without filter, and took it back up. We ran a best of 11.55 at 114.8 in the shootout. That was pretty surprising for us.

The next day with temps again in the 90s, we ran a best of 11.50 at 115.8 with the filter through the hood.

So that was pretty cool to see. We figure if we get back to some 60 degree days, this car might have an 11.2 in it. So that was cool to find.

We will try some scoop and filter modifications to try to replicate this with the shaker on. Maybe go to a dude scoop if needed.

Mike

[rad400]

Mike nice runs.

[gman005]

Hey Mike what happend to the car on Saturday i was talking to your dad he said you had some problems. Is everything ok?

[garrity455]

I am not exactly sure yet to be honest. My brother was driving in 3rd round Friday and after he got through the traps there was a backfire and a bang and the engine shutoff. When he tried to restart it he popped a couple of teeth off of the flywheel. He was already planning to go home that night, so we assumed we busted a rod or something else and put it up on the trailer and took it home. But yesterday, the engine would spin again once we got to a new tooth on the flywheel. Looks like we had leaned it out, with a bad float adjustment. Had to pull the bowl after trying to put on clear sight plugs and having them break Friday afternoon. So theory is, the float was off, the carb was lean, that played into the backfire.

But still not sure when the engine seemed locked up.

Going to pull the carb go over it again, do an oil change and get a new flexplate.

Then drive it around, and see if it really seems ok. Take it to the track and see if it still runs ok. We had been running 115.5 and ran 114.0 on our last run when we had the backfire and the engine stopped.

I am not positive everything is ok for sure yet, but it is better shape than we thought when it left the track that night.

[ta man]

What size is the filter you ran through the hood?

[garrity455]

I am not even sure, I will have to measure it. it was something my dad had. I would guess at 14x3 with filter lid. But not positive. here are a couple shots from the weekend, with my brother driving.

There are also a couple shots of my normal filter which is something like 10x2 I think.

[grandville455]

More than likely it was from the float being set way to low and it leaned it out too much!, I doubt the filter had a play in it. IMO

[garrity455]

Darby, yes two different questions.

John was asking about the engine and the backfire/lockup.

Ta man was just asking about filters, because we are dealing with similar filter limitations with shakers.

But not related. I need to do more testing on filter and shaker setups.

And I need to verify the engine is not hurt from whatever happened to cause us to pop teeth off of the flexplate after it died.

[gman005]

Good Luck Mike keep us posted.

[rad400]

Mike I saw a Pontiac race with a T/A use something like duct work and put it faceing the driver of the air cleaner. He said that this way the air was forced down the air cleaner to the carb he had an extreme lid. I forget how much he gain in the 1/4 doing this. ust a thought but I think u used a 5" by 14" air cleaner.

[garrity455]

Hey guys, figured I would give another update on the car. The engine is not ruined, but the carb we were running, has an issue (seems like stuck float), the carb keeps dumping fuel and flodding the engine, so we pulled that carb for now.

Anyhow, I have my old 750 holley on again.
The 1/2" open carb spacer was removed to add air filter clearance, and we are trying a drop base with 14" filter, with smaller filter on top of that.
The MSD was removed, and we are back to stock HEI with timing curve.
The shaker was also opened up a little.

So we ran at US 41 this past weekend, high 50s temps, good air.
So after getting timing set, and tire psi set, we ran 11.44s with air filters on and shaker on, around 116.5 mph. First time hitting 116 with the car, so that was cool.

We then took the shaker off, and ran the k&N filter and lid again with no shaker.
We ran an 11.31 and 11.33 at 117.2 mph.

So with the new modifications, the shaker on vs off only gained abotu .75 mph, rather than 1.5 it gained at Norwalk. But was still worth, just over one tenth.

So I am going to keep experimenting. One test we didn't try, that I wanted to, (we ran out of time) was the shaker on, but no filter at all. - So we still need to try that.

We also tried a new drop base filter, with smaller filter inside the shaker setup.

Here are some pics of the filters and the timeslips.

Mike

[garrity455]

These are the shots of the new filter setup we tried. With the 1/2 spacer off of the carb, we could use a drop pan and a 14 x 2 1/2" (ish) filter. We then used another base as a lid (we couldn't use the filter lid, because it hit the vent tubes). And we added another 10" filter on top that sits inside the shaker.

So we are getting closer. More testing to come.

And Cliff, we did try the 850 on the car at the house, but the car would die after a minute or two ideling in the driveway, we did have not figured out why yet, so we just ran my 750. We could restart it right away, but then in a minute or two it would die, it was pretty strange. We will look into that as well.

[rad400]

Mike I dont understand the double filter? Please explain.

[garrity455]

Well the filter you see on top, is the filter I have been running for years, as that is all that would fit on the car with the performer rpm and 1/2" carb spacer. it sat inside of the shaker. In my post from August 7th, you can see pictures of how that sit.

With the 1/2" carb spacer out, I can now run a 14" filter if I use the drop base, but I can run the 2.6" filter at most, while still closing the hood. The problem is, if I try to use the k&N filter lid, it hits the vents tubes. I could probably find a different 14" lid and put that on, but it would be about 1" above the mouth of the carb (because of the drop base).

So I figured it would be better to run the smaller filter on top of the 14" filter, than just a solid lid. And that filter will fit there, because it just sits inside of the shaker and still allows the hood to close.

Just your typical, 2nd gen firebird hood clearance issues with performer rpm intake.

I don't know if anyone has ever tried the stacked filter setup before.

Either way, next time out I intend to try the shaker on, with no air pan or filter.
If the car still runs faster with the shaker off, then I am going to try a bigger shaker (dude scoop), with no filter. If it runs as fast as no shaker, I will then try the stacked filters again. But if it slows down with dude scoop and no filter at all, then I don't know what to do.


Right now, fastest baseline is no shaker at all, with flat pan 14"x3" k&N and filter lid.

So next things to try.

1) Stock shaker, no air filter or pan. (If it runs as fast as no shaker, I know it is a filter issue, if it still slows down, then it is still a shaker issue).

2) Dude scoop, with no air filter or pan. Then determine results from there.

Then there is always the question of bigger carb than the 750, but I will get into that later.

And I could always try a single plan intake too.... Never ends, huh?