Turbo 301 runs 15.6

[JohnE]

I finally got the 1981 Turbo TA to the track, previous best was 15.8 By upping the boost 1.5 lbs (to 12) and adding 2 gallons of Toulene to improve the octane I was able to pick up about 2 tenths. I was actually having trouble launching hard due to tirespin...a new problem. I will try some slicks on the next outing.

Stock - 16.8 @ 82 mph

Best time - 15.6 @ 88 mph


JohnE

 

[81turbota]

Have you opened your hoodscoop yet? The stock aircleaner strangles these cars, I opened mine and kept the stock aircleaner base but put a small chrome lid on the stock filter. I still need to make a pan so I can seal it to the hood but, it made a big difference in the way the car feels. All you need to do is remove the hood mat (i just cut mine along the edge of the heat shield) and then remove the boost light panel. (I replaced my lights with a Stewart-Warner vac / boost gauge that I installed in the hood scoop opening and usede the wires from the normal light to light the gauge)

What other mods have you done?

 

[JohnE]

I kept the scoop closed because I am running the factory turbo light setup, cheesy I know, but I still like it. I also am running a boost gauge. For my air intake, I am running a 9" K&N tube filter below the air dam, connected to 3" flexible hose up to a turbo Buick chrome Q-Jet air intake. This gets cool air from the air dam and seems to work really well.

Other mods:

- 160 degree thermostat
- changed converter to honeycomb style
- modify carb secondaries to fully open
- adjustable boost controller

More mods to come!

JohnE

 

[b4black]

Congrats!

This is GREAT example of the Carb/Turbo potential. Sure, they aren't as fast as some cars stock, but how many other cars can you knock a second off (or more) with such simple mods?


All motors hit a "wall" were the cheap/easy stuff ends and the more serious/expensive work begins. When you have a SBC or 5.0, it doesn't take long before your changing intakes, carbs, heads, cams, etc. With these Carb/Turbo cars, that wall is a long way off.

Good Luck and keep us informed!!!!

PS - I have always thought the 301T's downpipe was bigger bottleneck than the Buick's. I bet changing it isn't an easy task.

 

[JohnE]

I think one of the reasons that it is easy to get a second or two out of these cars is that they were so DETUNED from the factory during that time period. Everyone was worried about emissions/economy versus performance.

I have been running Dyno2000 tests with this motor and believe you could get a mid 13 out of it, with the stock 3.08 rear.

With a stroke increase and 3.73 gears high 12's are indicated. As a verification test, I entered the vehicle combination from my 1978 455 Bandit Trans Am and Dyno2000 predicted a 12.80 quarter mile, the car actually runs 12.77...I was impressed.

JohnE

 

[81turbota]

How much timing are you running? Turbo TA's only have 8 deg advance stock which is pretty pathetic. Just out of curiousity you might want to dial back the boost a bit and try giving it some more timing. I have mine set at 14 deg initial with stock boost, this really seemed to help with my throttle response and off the line feel. (I haven't run it at the strip yet but I raced a 71 small block vette and was dead even with him)

 

[JohnE]

When I ran the car stock, I used factory timing with 9 lbs of boost. With 12 lbs of boost, I advanced the timing until audible knock, then slightly backed it off. I haven't checked it with a light yet, but I would guess around 10-12 degrees advanced. This is with 98 octane fuel.

Which connection are you supposed to ground out when checking the timing? I can never figure out which wire it is...

JohnE

 

[b4black]

I thought you were supposed to disconnect the EST (4-pin?) connector since you have an '81 with an ECM.

Am I correct that '80 and '81 301Ts are not as identical as everyone assumes? That '81's have ECMs while the '80 does not. If so, there are differences in how to tune them.

 

[81turbota]

My 81 doesn't have an ECM (no 81 Canadian cars do) and as far as I can tell is identical to an 80. I checked my repair manual and it doesn't specificly say how to set the timing with an ECM. I know on the 3RD gen F bodies there's a wire in front of the heater box you unplug. If memory serves me correctly it's brown and there's a connector right in the middle of it.

 

[JohnE]

The USA-spec '81s have the computerized carb/dist etc...I have owned 3 turbo TAs, but since they were all '81s, I'm not sure of all the differences.

 

[b4black]

The general trend was ECM's came to California in 1980, Federal in 1981 and Exports in 1982 (or even later). Trucks which are under different guidelines than cars, were ECM-less thorugh much of the 80's.