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 81 Trans Am 13.57 @ 100.94 mph
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Matt H
Cochise

USA
342 Posts

Posted - 13 Apr 2018 :  11:31:11 AM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Just wanted to share my recent experience at Atlanta Dragway.
My car is 81 trans am turbo pace car. Engine is a 461 stroker.
Holley 770 carb, RPM intake , 224/230 XR 276 compcam. Stock
6x8 unported heads. Turbo 350 trans 3200 stall , 308 rear gears,
275 /50/ 15 Nitto drag radials.

Ran twice, first run after heating the tires up and tried to launch at 2500 , blew the tires away , had to let off and get back into it. Ran 14.5 @ 98.

2nd pass fwas 13.57 @ 100.94 mph. 60 ft 2.1 , 330ft 5.6 , 1/8 8.7 , mph 81.15,
1000ft 11.34 , ET 13.57 Mph 100.94

2nd pass I heated up the drag radials and launched from idle. Spun a few feet then hooked and went. Would have done a 3rd pass but it was getting ready to rain.

What I did learn was the engine ' while it pulled good was laying down on the big end.
She is down 3-4 mph in trap speed. Overall was pleased with her performance.
Last week my brother and I welded in Detroit Speed subframe connectors. We also dropped the tank and changed out the sock filter. Next we are going to run a 1/2 " fuel line .
Plus going with Detroit Speed leaf springs. Working off his 2 post lift is awesome by the way. Only way to work on cars when your over 50 lol.

The Detroit Speed leaf springs will have a 2" drop after installed. Goal is to be able to launch at the 3200 stall get the 60 ft down to 1.8-1.9 that should allow me to get down to 13.00- 13.10 ET

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 13 Apr 2018 11:43:34 AM

ta man
Two Feathers

Canada
43 Posts

Posted - 13 Apr 2018 :  1:20:00 PM  Show Profile  Reply with Quote
Fuel supply is key for good ets. What does your fuel system consist of?

1980 Trans Am
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Matt H
Cochise

USA
342 Posts

Posted - 13 Apr 2018 :  1:31:24 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Pretty much stock . Fuel lines are all factory from the tank to the stock mechanical fuel pump. I beleive there 5/16 size. From the fuel pump to the Holley carb the line is 3/8 . Carb is a Holley 770 Cfm with vacuum secondaries.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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Matt H
Cochise

USA
342 Posts

Posted - 13 Aug 2018 :  11:54:55 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Update- Custom 3" exhaust from headers back. New Summit stainless steel mufflers. I had almost 20 hrs in the exhaust, measuring, fitting, welding and grinding. Looks better than any muffler shop can do.
All mandrel bent pieces, Exhaust is tucked up nicely. None of that hanging down almost dragging the ground junk.

Welded in Detroit Speed sub frame connectors, installed Detroit Speed leaf springs, will lower the car 2" from stock height. Ran 1/2" fuel line from the tank to the mechanical fuel pump. Then AN 8 from
fuel pump to carb.
She launches hard now with the new suspension pieces in place. Runs very strong now, seems to pull hard up top now.

Will be heading to Atlanta Dragway in mid September to see if she can improve her time.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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Corncob2061
Cochise

USA
266 Posts

Posted - 14 Aug 2018 :  01:26:17 AM  Show Profile  Reply with Quote
Looks like your headed into the twelves :) Jay
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Matt H
Cochise

USA
342 Posts

Posted - 14 Aug 2018 :  8:32:40 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Thanks Jay , that will be icing on the cake to run in the 12's. My brother thinks it may just happen.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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Phil
The Great White Buffalo

USA
7284 Posts

Posted - 15 Aug 2018 :  12:02:28 PM  Show Profile  Reply with Quote
Nicely done Matt! There is quite a bit more in that engine so keep picking away at the details.

What/whos 3500 TQ converter do you have?

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.

Edited by - Phil on 30 Aug 2018 10:02:12 AM
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Matt H
Cochise

USA
342 Posts

Posted - 15 Aug 2018 :  10:10:28 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Thanks Phil- No markings on the TQ converter. I do know its a 10" cause I measured it. It is tiny lol. I was told when I got the car that it
was a 3200 stall. I really don't think that's the case. Before I put the drag radials on it. I stalled it up to about 2800-3000 rpm
and the rear street tires started to break loose. I am thinking its in that 2800-3000 range. I know she gets in that torque power band
very quickly.

Yes your right about the details. My brother and I are looking over every possible way to utilize that Pontiac torque. I may even put a set
of Caltracs on her, depends how well she hooks at the track.

Wish my old 79 4spd 400 ran this good. But it was number matching.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 15 Aug 2018 10:18:51 PM
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Cliff R
Crazy Horse

USA
545 Posts

Posted - 18 Aug 2018 :  07:20:11 AM  Show Profile  Visit Cliff R's Homepage  Reply with Quote
A 455 topped with 6X heads and using a HR cam should EASILY put a 4000' car into the 12's. The MPH is WAY down for what you are doing so I'd start by making sure that you are keeping the carb full on hard runs and get the suspension working for better 60's times.

With a good 10" converter you should be in the 1.7-1.8 second range for 60's times, which will lower ET by nearly half a second without any other changes.

Even with poor traction you should be closer to 110mph than 100mph, so work on fuel delivery/tuning and I'll bet you'll get your 12 second time slip without a lot of additional changes......Cliff

If you can read this, thank a teacher. If you can read this in English, thank a Veteran.
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cortcomp
Coyote

USA
5440 Posts

Posted - 18 Aug 2018 :  11:16:28 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
What do you guys figure for the difference between the same car stick vs auto? Ruling out the reaction time of the drive of course. Is it easier to tune considering you don't have different converters to play with or does the converter help vs a direct drive, off the line?
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Cliff R
Crazy Horse

USA
545 Posts

Posted - 18 Aug 2018 :  10:34:11 PM  Show Profile  Visit Cliff R's Homepage  Reply with Quote
A good 10" converter will EASILY net 1.6 something 60' times behind a stout 455. I sold Continental converters for over 20 years and can't think of a single one we put behind a 455 making 1hp/CID or greater that didn't run very good 60' times at the track. Of course this assumes good traction and you've got to hook to even find out how well the converter works.

The only slippage with a stick shift car after you find traction is the clutch, so the driver becomes the "converter" of power to the pavement......Cliff

If you can read this, thank a teacher. If you can read this in English, thank a Veteran.
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Corncob2061
Cochise

USA
266 Posts

Posted - 20 Aug 2018 :  10:57:26 AM  Show Profile  Reply with Quote
Matt there are some very fast cars with 3.08 gears running tight street converters for cruising that flash to 3 to 4K at full throttle. It has made me take a second look. I like that set up like yours. How does your car do cruising below the stall speed?

I think the low first gear set helps the manual trans a lot. It seems like it takes a good tuner and driver to get big HP down the track with a stick. Especially without the low first or a deep gear. My brother went from a 3 speed with a 3.09 first gear to a 2.44 first gear 4 speed and the car was half a second slower with the 4 speed. All lost in the 60 ft. I will be trying to get my 77 ta down the track with 450 hp 406, 3.23 and st10. Already thinking I need a m23z with the lower first. I guess I will find out...Jay

Edited by - Corncob2061 on 20 Aug 2018 3:57:37 PM
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Corncob2061
Cochise

USA
266 Posts

Posted - 20 Aug 2018 :  4:09:50 PM  Show Profile  Reply with Quote
Since you do not know exactly which converter your car has. I will mention we ran a car with a 10 inch converter once that it did not matter what engine it had infront, it would run 100mph. Finally switched converters and it went 108mph. That was frustrating. I think you will be ok, just remember that if you start making changes that should send the car faster that do not work.Jay
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Matt H
Cochise

USA
342 Posts

Posted - 21 Aug 2018 :  8:43:24 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Jay- my brother brought that subject up about the converter. Its very possible the converter could be the problem. We will find out soon enough. We are hoping that the problem is fuel related and
should be corrected now with the 1/2" fuel line. If not then we will venture into the converter world.
No issues while cruising around. Big torque from the 461 makes it effortless. I will say backing out of my driveway which is steep where it meets the street, she sounds like a 4 spd car.

Jay I hope you are running drag radials. You will need them with your 4spd car and 450 hp . I ran a 79 400 4speed TA with way less power than yours and never had a good sixty foot. 2.1-2.3 consistent and that was with a 300 hp at the flywheel. That was on street tires.
There is nothing wrong with your BW super t-10. They are great transmissions.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 21 Aug 2018 8:55:06 PM
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Matt H
Cochise

USA
342 Posts

Posted - 03 Sep 2018 :  11:10:50 AM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Update- have not run the car yet. But did find out it is shifting from first to second gear at 4600-4800 rpm at full throttle. Same with 2nd to 3rd gear. What this means is there is a lot more
power to be had if I shift her at 5500-6000 rpm. When I ran the car at the dragstrip I left the car in drive as most would. Well my brother pointed out in the videos the car never really made
a lot of noise. The exhaust seemed to be at monotone level. Never really heard it increase in rpms. Well I know that the governor weights and springs will have to be changed or modified to bring the
shift point up to the 5500-6000 rpm. This is a turbo 350 trans. What this tells me is the transmission while it was rebuilt, the shift points were never changed. This trans is still shifting in the
factory settings 4600-4800rpm for the anemic 301 turbo engine that originally came in the car. B & M sells a governor kit for 75 bucks that will fix the problem. It is weights and springs. Or I could
remove the out weights weigh them on a food scale. Stock they are like 16 grams. Grind them down to 11 or 12 grams and this will bring up the shift points. Obviously it will be a trial and error venture to
get the right weight for the right shift points. But until then I can see what she will do if I manually shift the trans.

I took her out the other day and shifted her at 6k manually from 1st to 2nd gear. Huge difference. Engine really keeps you pressed back in the seat. Well I shifted from 1st to second gear at 60 mph.
2nd-3rd at 85 mph. Then let off. With the car in drive at full throttle it would shift out of 1st to 2nd at 45 mph! Well this may explain the slow 101 mph in 1320 ft and a 13.57 et.

With this now known and the other things my brother and I have done to the car. I really think she will run into the 12's.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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Corncob2061
Cochise

USA
266 Posts

Posted - 06 Sep 2018 :  10:24:08 AM  Show Profile  Reply with Quote
Maybe you have seen this article, looks very close to your engine with a little more head flow. Defineltly puts out the torque! Jay

http://www.hotrod.com/articles/hppp-1208-467ci-pontiac-engine-stuska-dyno/amp/

Edited by - Corncob2061 on 06 Sep 2018 2:10:26 PM
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Matt H
Cochise

USA
342 Posts

Posted - 08 Sep 2018 :  12:07:27 AM  Show Profile  Visit Matt H's Homepage  Reply with Quote
That's are good article. I haven't seen that one. Pretty impressive Pontiac hp and torque.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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DanM
Sitting Bull

113 Posts

Posted - 18 Sep 2018 :  6:14:22 PM  Show Profile  Reply with Quote
You will take at least a half second off your ET by shifting at the right point, maybe more.

Assuming you have a tach, or can get a tach somewhere at least temporarily practice manually shifting from L-2, and 2-D to determine when you need to "lead" the shift so you don't over rev. (there will be a slight delay from when you move your arm to when it shifts. It could be 500 rpm.)

I recommend trying to shift at 5500 for now. 6000 is a bit high if you haven't done anything to the rotating assembly to make sure it can handle that. Mainly you need to know that your connecting rods are not stock and didn't have much fatigue. Secondarily you need to know that your valve springs can keep up.

Once you get good at shifting precisely at 5500 try a few runs at the track back to back to compare ETs for 5200 vs 5800.

Then report back please.

I agree with Cliff R. A 461 should get you into under 12.5 when everything is running perfectly. That cam is a tad mild for 11's is my guess and probably cant make use of anything over 5500 rpm.

Your 60 foot time of 2.1 is decent. There's nothing broken with your torque converter. The 275 drag radials are a bit much in my opinion. Shorter tires will get you more acceleration and cut your 60 foot time, maybe to 1.98. The 3.08 gears are also a tad tall to expect much more out of your 60 foot times.
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Matt H
Cochise

USA
342 Posts

Posted - 19 Sep 2018 :  11:09:07 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Dan I will definitely report back. Bottom end is supposed to be a forged crank, H beam rods and forged pistons. I am more comfortable shifting at 5500 than 6000. Last thing
I want to do is hurt the engine. I am not expecting much more out of the 60 ft but it could pick up a tenth or two due to the new Detroit leaf springs/ sub-frame connectors. Who knows. Will run the
DRs at 18 psi like last time and see what happens. But I do expect to pick up the mph with the new 3" exhaust and shifting at 5500. At this point we are waiting for the weather
temp to drop. Its still in the 90s here in GA.

I got two videos of me racing the same 2017 Challenger 8spd auto 392 on DRs. One video I tried launching at 2500 and blew the DRs away. Second I launched from idle and stayed ahead of the big 392 to half track.
Yep but shifting at 4600-4800 in Drive really killed it. That big 392 Dodge with 485 hp came on strong at the top end he trapped 112 with a 12.6 time.

Looking to do much better this time.


Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 19 Sep 2018 11:14:00 PM
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Matt H
Cochise

USA
342 Posts

Posted - 14 Oct 2018 :  8:51:57 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
UPDATE - I went to the track Friday night with cooler temperatures finally.
I only ran one time as the mph was about a 1 mph difference, still starving for fuel on the topend. But 60 ft really improved.

Here is the time slip break down . RT .236 60' 1.92 , 330' 5.50 sec ,1/8 mile 8.53 sec , mph 80.70 , 1000ft 10.70 sec ET- 13.44
MPH 99.87

All the suspension work paid off. 60 ft time was 1.9 vs the old 2.1 ET improved by a tenth. 2 tenths quicker to the 1/8 mile. 6 tenths
faster to 1000 ft. But really fell off in the top end mph in the last 320 ft.

Looking to remove the mechanical fuel pump. Block it off and run a
electric fuel pump with a regulator. You guys having any other thoughts?

Here is a video of the run. Mustang had a turbo but he could not hook. He played catch up but didn't have enough to catch me for the win.

https://www.youtube.com/watch?v=8d_7SlJz8B4

Heating up the drag radials video

https://www.youtube.com/watch?v=NdhENETz_mI


Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 14 Oct 2018 9:22:21 PM
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Corncob2061
Cochise

USA
266 Posts

Posted - 14 Oct 2018 :  10:43:07 PM  Show Profile  Reply with Quote
That does sound like a fuel issue, you should have taken .4ths off the quarter mile et just from your better short time. To me it depends how quick your planning on getting your car to run. Below 1.8s and the electric fuel pump like the Holley and Carter street pumps have gave me a lot trouble. Some others go faster than that by cleverly mounting the pump, sometimes behind the tank. If your content with that 1.9 short time you should be fine with the out of tank electric. I have ran out of tank electrics a lot faster than that, but with fuel cells.

Some race classes are pretty quick, require a mech pump, and can not run anything electric. Probably could get there with a good mech pump and something to scavenge the fuel in the tank better.

On stock tanks I prefer the intank electric pumps if you want to go fast, that way the pump has a built in sump that keeps the pump in fuel. Especially with the fuel level high. But it is more work. I would probably buy another gas tank and install the intank pump and swap fuel tanks. Jay
http://www.hotrod.com/articles/aeromotives-tank-pumps-carburetors/amp/

Edited by - Corncob2061 on 14 Oct 2018 11:06:31 PM
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Corncob2061
Cochise

USA
266 Posts

Posted - 14 Oct 2018 :  11:12:22 PM  Show Profile  Reply with Quote
Looked like your car was really planted coming off the line. Good job! Jay
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Phil
The Great White Buffalo

USA
7284 Posts

Posted - 15 Oct 2018 :  11:49:44 AM  Show Profile  Reply with Quote
I second the intank pump. I screwed around for years trying this and that including sumping the tank, using a Holley garbage grinder pump and regulator, 1/2" line all the way from tank to carb, etc. etc. and still had a 400 that layed down half way through 2nd gear.

I finally went to an intank setup with a 255 l/hr Walbro and EFI to carb regulator and the difference is night and day. And now, even with a major engine upgrade (462/KRE/HR), I have a steady 6 lbs of fuel no matter what the conditions. And no noisy pump hanging under the car waiting for an accident.

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.

Edited by - Phil on 15 Oct 2018 11:51:29 AM
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Matt H
Cochise

USA
342 Posts

Posted - 15 Oct 2018 :  12:42:40 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Thanks Jay and Phil. The car is hooking hard. The new Detroit leaf springs , sub frame connectors and DRs did there job. Goal is to run into the 12s with my 3.08 gears.
I thought the 1/2 fuel line would have fixed the fuel starvation on the top end but it did not. At first I thought about going with a Robbmc
mechanical pump or the high performance Carter mechanical pump. Not crazy about the external electric fuel pumps. Noisy for one
and would always worry about it failing from heat or road debris hitting it at that least suspecting time. I like the in tank set up and
will look into that. That way if I ever go EFI I will already have the fuel system ready.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 15 Oct 2018 12:45:23 PM
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Phil
The Great White Buffalo

USA
7284 Posts

Posted - 19 Oct 2018 :  2:30:03 PM  Show Profile  Reply with Quote
Matt, just take the time to run the same size hard lines (feed and return) when you do it. This will prevent unstable pressures and pressure creep. Also, if/when you go to EFI, you just yank the carb friendly regulator out and install the EFI. I bought a roll of 3/8" coated steel line from Summit and flared the ends. I also used a frame mounted AC fuel filter setup from a Buick GN. I welded the brackets to the back side of a frame connector so its well protected and up/out of sight.

I also used a Ford inertia switch mounted in the trunk behind the taillight panel. Lots of folks use the oil pressure switch and that's not a bad idea, I just find the inertia switch a better way to go. I have seen cars in accidents that are still running so I am not a subscriber to the oil pressure switch method. Or you could use both and wire in the same circuit.

Bowties are for Pee-wee Herman. LS swaps in Pontiacs should only apply to Fieros.
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Matt H
Cochise

USA
342 Posts

Posted - 20 Oct 2018 :  7:48:04 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Phil I just received my 255 Walbro in tank pump today. Also a regulator with a return . Still have to get my wiring and all.
How do you like your EFI ? Which one did you go with.?

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET

Edited by - Matt H on 20 Oct 2018 7:49:06 PM
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hdinch
Tribal Scout

USA
2 Posts

Posted - 08 Nov 2018 :  10:10:51 AM  Show Profile  Reply with Quote
Following...how did the pump installation go? I am looking at fuel upgrades myself. Running a 461 in my 73 bird. 1/2 line with a Carter high flow pump. Caltracs\15 in Drag radials with a best of 12.011 in the quarter and 1.65 60ft. I think fuel and maybe the trans could be an issue. I had just removed the trans and had it looked at all the clutches for high gear where toast. This was supposed to have been rebuilt by a local guy whom was associated with Central Virginia Machine shop...so now to get it done right. Anyway following your progress on this as I think fuel might be an issue also. That setup will take a lot of mods it seems to get it completely done.
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Matt H
Cochise

USA
342 Posts

Posted - 10 Nov 2018 :  8:23:04 PM  Show Profile  Visit Matt H's Homepage  Reply with Quote
Hdinch- I have everything needed to do the in tank pump. Just haven't done it yet. I thought about going to a better mechanical pump but I will be spraying
a 150 shot in the future. The fuel system has to be right . Over the winter I will get the new walbro in tank installed. Plus relocating the battery to the trunk.
Goal is to run in the 12s with 3.08s . Goal with 150 shot will be to run in the 11s. The in tank pump isn't that hard. I thought it would be . My brother put two in his
fuel tank last week. It's not that bad at all.
I have to do all I can as my brothers beautiful 76 TA is almost done . He is running a LS 6.0 with a 76 mm turbo. 4l80 with a 4 link rear and 3.23 gears.
I have to try to keep him in sight. We are figuring around 700 rwhp to start with 18 lbs of boost . Will dial it up as needed.

Sounds like your 461 is running pretty strong. Sorry to hear about your trans. I know when I get mine running 100 % I wonder how long my turbo 350 will
live. It's supposbly been rebuilt with good parts but as you know a 461 torque can be brutal on drive train parts.

Matt
1981 Pontiac TA Pace Car
461 with 6x8 stock iron heads. HR 224/230 3.08 gears
13.44 ET
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