I have a 1980 Trans AM with a 301 Turbo. As you all know, this combination is pretty gutless. I know of all the downfalls with this combination, but what can really be down to improve its performance?? The typical response I get for this question is "get rid of the 301"....Sometimes I can't argue with that reply. All that aside, though, what can be done. Can this be a 14 sec car....13 sec car??? I read about someone that drag races a 301T, and apparantly runs in the 13-12 sec range. Anyone have any info on what was done to that T/A. Any help would be appreciated. Thanks
Pontiac 301 Turbo
- Thread starter cjnico1
- Start date
Neil Smedley
New Member
- Joined
- Jun 17, 2001
I would be glad to help you.........send me your phone number and when you can be reached.........I am the guy who was foolish enough to try and race one of these cars......My car still holds the NHRA P/SA record at 12.46.........Neil Smedley
b4black
Well-Known Member
- Joined
- May 24, 2001
It would be nice to discuss it hear, instead offline in private. Sharing info is the greatest benefit of these boards. 
Upping boost/supressing knock is the key. Get a good boost gauge and see where you are. Make the wastegate actuator adjsutable, if it isn't already. Since you don't have an ECM, monitoring knock is difficult.
An MSD 6 BTM is something to consider.
The 301T's Downpipe looks tiny. I would consider getting a bigger one. It's would be great if you could get ATR to do one.
A simple Alcohol Injection system would do wonders. A washer pump spraying just before the carb could get you into the 14's alone.
Upping boost/supressing knock is the key. Get a good boost gauge and see where you are. Make the wastegate actuator adjsutable, if it isn't already. Since you don't have an ECM, monitoring knock is difficult.
An MSD 6 BTM is something to consider.
The 301T's Downpipe looks tiny. I would consider getting a bigger one. It's would be great if you could get ATR to do one.
A simple Alcohol Injection system would do wonders. A washer pump spraying just before the carb could get you into the 14's alone.
How about doing one of the changes GM did?
A 200R4 trans behind the turbo motor.
Lower first gear and a mid 2K stall for a better start out.
A higher top gear and lock-up for mileage and cruising.
Add the 3.42 gears in that 8.5 rear.
These would help wake the car up before you add anything to the motor.
As Rich said, open the intake and exhaust flow of air. The turbo cars were all pretty bottled up from the factory.
I had a friend with one of these when they first came out. Steve learned early on that it took load on the engine to produce boost. I swear that guy drove with both feet all the time. He was brake boosting at stop signs and I was always impressed with how the car ran and handled.
A 200R4 trans behind the turbo motor.
Lower first gear and a mid 2K stall for a better start out.
A higher top gear and lock-up for mileage and cruising.
Add the 3.42 gears in that 8.5 rear.
These would help wake the car up before you add anything to the motor.
As Rich said, open the intake and exhaust flow of air. The turbo cars were all pretty bottled up from the factory.
I had a friend with one of these when they first came out. Steve learned early on that it took load on the engine to produce boost. I swear that guy drove with both feet all the time. He was brake boosting at stop signs and I was always impressed with how the car ran and handled.
Thanks for the responses guys. That's some good information. I'm looking forward to speaking with Neil to see what he has done with his car and what he recommends.
A larger diameter downpipe seems directionally correct. From the groups experience, how much is this worth?? A free flowing exhaust seems directionally correct also, but I don't know how this engine responds to changes. My car currently has the factory exhaust...Original pellet converter, and factory stock mufflers. If I went with a monolith converter (or even a straight pipe) and 2 1/2" pipes before and after the mufflers, would that make a significant improvement in performance??
Going to a steeper gear with a 200R4 transmission to imporve torque multiplication seems good too. Are there any of you out there that have tried this?? What about converting to a manual transmission?? I have a T56 aftermarket transmission laying around that I bought for another project car, but never used. Is this a good alternative??
As far as water injection goes, is it best to "squirt" water into the carb, or use a high pressure pump to "inject" water after the turbo. It seems that the temperature drop would be the greatest if you inject after the turbo.
What do you guys think?? Again, thanks for you help.
A larger diameter downpipe seems directionally correct. From the groups experience, how much is this worth?? A free flowing exhaust seems directionally correct also, but I don't know how this engine responds to changes. My car currently has the factory exhaust...Original pellet converter, and factory stock mufflers. If I went with a monolith converter (or even a straight pipe) and 2 1/2" pipes before and after the mufflers, would that make a significant improvement in performance??
Going to a steeper gear with a 200R4 transmission to imporve torque multiplication seems good too. Are there any of you out there that have tried this?? What about converting to a manual transmission?? I have a T56 aftermarket transmission laying around that I bought for another project car, but never used. Is this a good alternative??
As far as water injection goes, is it best to "squirt" water into the carb, or use a high pressure pump to "inject" water after the turbo. It seems that the temperature drop would be the greatest if you inject after the turbo.
What do you guys think?? Again, thanks for you help.
Neil Smedley
New Member
- Joined
- Jun 17, 2001
The main thing thats wrong with this deal is the quadrajunk carb. There is no way that a stock fuel pump can keep that carb full with only one inlet needle and seat.....To further complicate things, the factory saw fit to put 29 thousanths tip rods in the rear....This is WAY too rich and causes the carb to run out of fuel and detonate even sooner....If your serious about going faster and having the motor live, you will have to put an electric fuel pump on the car and regulator......My rods of choice are the medium length .057 ones.....The carb needs a little adjustment to let the rear air door open all the way also.....I was able to run mine at 20 lbs of boost.....I don`t think more than 13-14 should be run on the street........I have a burned head gasket collection to remind me of failed experiments.....I am currently building a carbed 79 regal for NHRA stock eliminator and would appreciate any input you guys have for this white elephant........
b4black
Well-Known Member
- Joined
- May 24, 2001
So far I love the Q-jet. Mine was running out of fuel, but it turns out it was the inlet fuel filter. Replaced it with a larger in-line unit and problem solved. I do want to step up to an eletric pump though for peice of mind.
I was running stock rods and hanger in the secondaries. Alcohol injection was supressing knock, but I must have been very lean. I richened the rods and picked up a full ½ second.
I squirt my alcohol before the carb. I chose this for two reason. I was concerned that after the turbo would result in poor distribution to the cylinders - before the carb means full atomization. Second, after the turbo means removing the turbo to install the nozzle and adding a solenoid to prevent vacuum from sucking the alcohol in. Before the carb is just easy.
I have an ECM, which lets me run a knock gauge like the 84/87 SFI Turbo Buicks have. If I had a pre-ECM engine, I would install a second sensor and run a knock gauge. I can't see tuning without one.
I was running stock rods and hanger in the secondaries. Alcohol injection was supressing knock, but I must have been very lean. I richened the rods and picked up a full ½ second.
I squirt my alcohol before the carb. I chose this for two reason. I was concerned that after the turbo would result in poor distribution to the cylinders - before the carb means full atomization. Second, after the turbo means removing the turbo to install the nozzle and adding a solenoid to prevent vacuum from sucking the alcohol in. Before the carb is just easy.
I have an ECM, which lets me run a knock gauge like the 84/87 SFI Turbo Buicks have. If I had a pre-ECM engine, I would install a second sensor and run a knock gauge. I can't see tuning without one.
b4black
Well-Known Member
- Joined
- May 24, 2001
In my signature is a link to the '83 TR, but it hasn't been updated for a while.
Significant mods are:
MSD 6 BTM
Alcohol Injection
High stall torque converter
Suspension
K&N cone filter
open exhaust (after DP)
Stock long block, turbo and carb (tweaked). Daily driver, passes emissions with a converter.
I ran a 14.85 @ 92 this year. Car was in the 17's when I bought it.
PS- most of the Turbo Buick guys that post often moved over to www.turbobuicksX.com (you'll have to copy and paste without the X)
Significant mods are:
MSD 6 BTM
Alcohol Injection
High stall torque converter
Suspension
K&N cone filter
open exhaust (after DP)
Stock long block, turbo and carb (tweaked). Daily driver, passes emissions with a converter.
I ran a 14.85 @ 92 this year. Car was in the 17's when I bought it.
PS- most of the Turbo Buick guys that post often moved over to www.turbobuicksX.com (you'll have to copy and paste without the X)
I know the "stock" engine will respond well to a less restrictive exhaust. When I first got my 81, I removed the catalytic converter. The engine was challenged to get a max of 3 psi with the cat. Without it, it was able to get to levels around 8. Granted, with that kind of change, it would seem that my cat was *far* below optimal. But, like most engines, it can benefit from a better exhaust system. I would imagine it would be very important to monitor knock after making exhaust changes. If there's less exhaust gas in the cylinder, the tendency to knock is going to go up.
I'm in the process of installing a throttle body injection system in place of the Q-jet. I generally like Q-jets. But, the electronic version has given me more problems than I care to admit. I'm using an ECM from the Syclone/Typhoon since it already comprehends boost. Since my 81 was already equipped with an ECM, most of the sensors and wiring are already present. With available parts, it's easy to mount the TBI where the Q-jet used to be.
I've also installed a 200-4R transmission with a 2200 stall converter. The swap is extremely easy. To make things simple, I bought a new crossmember from Bowtie Overdrives. With this crossmember, the transmission bolts right up. I've also purchased a new detent plate for the shifter to support the "extra" gear selection. If you're creative, I'm sure you could fab up the parts above instead of buying them.
Unfortunately, I haven't completed the project to give you any performance numbers. The engine will start and idle. But, the car is still on jackstands waiting to get the gas tank modified to support the fuel injection needs. (Return fuel line and some sort of sump.)
While I've been doing this, I've been thinking about the mounting of the turbo. I've seen what 3rd gen F-bodies are doing to mount turbochargers. And, I think it would be interesting to try this on a 2nd gen. If there's a way to relocate the AC (assuming you have AC and want to keep it), I'd like to try to mount the turbo in that area. The advantages I see are .... 1) a potentially more direct (i.e. fewer bends) route to the bottom of the car for the exhaust pipe, 2) the potential to go "blow through" instead of "draw through" and 3) the ability to use an intercooler. I haven't tried doing this. But, I think it will be the next project after I get the TA off of the stands.
Let me know if you have any questions.
Thanks for all the great input. As far as exhaust is concerned, I'm going to look into having a local shop fab up a 2 1/2 in. down pipe. I'm also going to have a straight pipe made to eliminate the converter. Now, as far as the rest of the exhaust is concerned, as I mentioned before, I have a factory system, with factory mufflers. I havent measured the stock pipes, but my assumption is that they ar 2 1/4". Would the performance improvement to change to 2 1/2" pipes be worth the money, or should I save the money and put on a set of low restriction mufflers. My reasoning is that the motor is only 301 cu. in.....Does it require (or will it see the benfits of) 2 1/2" pipes (before and after the mufflers).
On a different note, the heads obviously have siamese ports. Has anyone looked at the port size differences?? I have an extra set of heads and was going to modify the ports so that they are all the same size. There seems to be enough material to do that. The intake is another story, though. I did find a place that modifies cast iron, and they indicated that they can modify the ports. My question to this group is....are the port sizes configured like this for some air/fuel distribution issue, or for fuel economy?? Has anyone ever tried modifying the ports...or slightly larger valves??
As far as transmissions go, anyone have any experience with putting a manual transmission behind the 301T. Like I indicated in a prior post, I have a t56 laying around that I was contemplating putting in the car. Any thoughts???
Con
On a different note, the heads obviously have siamese ports. Has anyone looked at the port size differences?? I have an extra set of heads and was going to modify the ports so that they are all the same size. There seems to be enough material to do that. The intake is another story, though. I did find a place that modifies cast iron, and they indicated that they can modify the ports. My question to this group is....are the port sizes configured like this for some air/fuel distribution issue, or for fuel economy?? Has anyone ever tried modifying the ports...or slightly larger valves??
As far as transmissions go, anyone have any experience with putting a manual transmission behind the 301T. Like I indicated in a prior post, I have a t56 laying around that I was contemplating putting in the car. Any thoughts???
Con
Do talk to Neil. He has a wealth of information and has already done all of the experimenting for us.. Yes you will benifit with the bigger exhaust. Turbo's don't like flow restrictions. When you get the boost dialedin the motor will be more like a hopped up 400 so the exhaust is necessary. I fabbed up my own exhaust system on my car. It's much better than stock and looks a ton better. All mandrel bent. Every little bit helps with this car and the exhaust system play a major role in that. Good luck.
