Which is faster 6.6 or 4.9T?
- Thread starter lee5490
- Start date
I like the 6.6 better. The carbureted turbo setup of the 4.9 left something to be desired along the lines of spool up, driveability, and power. Im sure with some tweaking and modern technology such as wideband 02 tuning, one could improve upon the capabilities of the 4.9 turbo by leaps and bounds.
Knowing that they have pushed the carbed 3.8 turbo setup into the 13s without much work, im sure the 4.9 has similar potential, its just how much time and testing your willing to devote to the project.
4.9s are not known to be the best base for building hp anyway, with too many weak points to make it really worthwhile. A 6.6 on the other hand has much more history as a performance engine, more aftermarket support, higher production numbers so more parts available, and less headaches trying to make it run right.
Make your choice.
Knowing that they have pushed the carbed 3.8 turbo setup into the 13s without much work, im sure the 4.9 has similar potential, its just how much time and testing your willing to devote to the project.
4.9s are not known to be the best base for building hp anyway, with too many weak points to make it really worthwhile. A 6.6 on the other hand has much more history as a performance engine, more aftermarket support, higher production numbers so more parts available, and less headaches trying to make it run right.
Make your choice.
Brer Rabbit
Pursuit Specialist
- Joined
- Feb 5, 2005
Go with the 6.6.
First off in bone stock trim my buddies trans am would inch away from my bone stock 1978 Z28 on the big end. My Z ran 15.42 all day long :biggrin
Flyin lol) Ahhhh the good old days where have they gone , but anyway that pontiac 400 motor now has a endless amount of build up options, including a big stroker assembly combined with edelbrock aluminum heads that make over 500 horsepower on 93 octane! Jim Butler performance has those assemblies by the way---also I saw a low compression version of that stroker motor in a gold 67 GTO with a single turbo on it, and I think the guy has been making 10 second passes consistently. The 3.8s and 4.1s make a lot of torque but I think that pontiac motor should be the king of torque that way. Good luck.
First off in bone stock trim my buddies trans am would inch away from my bone stock 1978 Z28 on the big end. My Z ran 15.42 all day long :biggrin
Flyin lol) Ahhhh the good old days where have they gone , but anyway that pontiac 400 motor now has a endless amount of build up options, including a big stroker assembly combined with edelbrock aluminum heads that make over 500 horsepower on 93 octane! Jim Butler performance has those assemblies by the way---also I saw a low compression version of that stroker motor in a gold 67 GTO with a single turbo on it, and I think the guy has been making 10 second passes consistently. The 3.8s and 4.1s make a lot of torque but I think that pontiac motor should be the king of torque that way. Good luck.Bird of Prey
Member
- Joined
- Sep 30, 2004
hey hey hey!
i had a 81 301Turbo and i liked it alot!
if you buy a turbo be sure it is a well and often maintained vehicle. the 6.6 are more stable if you want.
6.6 = torque
4,9 T = cruiser
i had a 81 301Turbo and i liked it alot!
if you buy a turbo be sure it is a well and often maintained vehicle. the 6.6 are more stable if you want.
6.6 = torque
4,9 T = cruiser
turbot2496
New Member
- Joined
- Mar 16, 2003
Back in the day... I could take a 6.6 in my 301T, raced several stock ones..... but I agree there crap and if I had to choose I would take the 6.6.... alot more options with it...
no comparison. I was in HS in those years and there were many of both.. The 6.6's (even the olds motors) were wayyyy faster then the 4.9T's. They were laughed at even back then.. If you can get the TA 6.6 (as opposed to the standard 6.6)which were the higher output Pontiac engines..
turbot2496
New Member
- Joined
- Mar 16, 2003
Bone stock off the show room floor the 301t could take the stock 6.6 of the same year range.... thats my story and I'm sticking to it.....been there and done it several times...301t was a finicky car and minor things could make a major difference in performance... I do agree though.... they were still crap... and I would rather have a 6.6 ..... although back in HS in the day when I had mine 301t(silver with burgandy interior... very sweet looking car) I was KING of the world.... LOL
1979 6.6 220hp@4000 rpm 320tq@2800 rpm
1979 403 olds 185hp@4800rpm 320tq@2200rpm
1980 301t 210hp@4000rpm 345tq@2000rpm
No 6.6 in 1980
As you know buick brother torque down low wins races
and as you see from the factory hp figures my car would jump a 6.6 off the line by alot and hold him off by several cars well up to 100mph...... few mods on the 6.6 though .... and I was toast 
ITSAV6
It's my Granny's car!
- Joined
- Nov 13, 2001
6.6 v/s 301T
My cousin bought a '80 Turbo T/A new. He traded his gold 77 T/A in. The 301T was a SLOW turd. It was beautiful Bandit car,but a turd. He made 2 payments and traded for a 79 10th aniv T/A 4 speed. Major improvement in speed department. I rode in all 3 and the 79 was the fastest by far.
My cousin bought a '80 Turbo T/A new. He traded his gold 77 T/A in. The 301T was a SLOW turd. It was beautiful Bandit car,but a turd. He made 2 payments and traded for a 79 10th aniv T/A 4 speed. Major improvement in speed department. I rode in all 3 and the 79 was the fastest by far.
turbot2496
New Member
- Joined
- Mar 16, 2003
A friend of mine wanted one years later after I had mine. He found one on a used car lot and we took it for a test drive.... one of the slowest cars I had ever rode in.... I couldn't believe it .... I was like WTF??? So eventually we pulled over and popped the hood to check it out and the frickin turbo had been bypassed. It had regular 301 exhaust manifolds on it and the turbo was still there. 301 at 7.5 to 1 compression.... talk about a recipe for power.
Octane, as for our cars, was also very important on those old 301t's and good fuel wasn't as abundant back then as is now. Imagine driving your GN on 87 octane and trying to race...or even 89. I'm sure you get the picture and thats what alot of guys tried to do with these cars so naturally in that aspect they ran like crap because the computer limited boost and pulled timing like our cars. Generally if you were smart you filled up with the highest octane you could find added a couple bottles of octane booster if you knew you were going to get on it. I was young and didn't know crap about the car but had a older friend that was a pretty knowlegable mechanic and racer that helped me out and learned me about detonation etc...
Back then several people were suprised at how well my car ran as 301t's had a pretty bad rep.
Eventually I ended up having some computer problems or something and my mechanic talked me into taking all the computer crap off and putting a regular distributor in it etc.. Long story short.. this was a lot harder mod than he thought it would be and had the car for 2 weeks getting it to run right... Anyway when I got the car back... WOW it ran better than ever..... for about a week until it blew a headgasket.... no stock computer .... no retarding the timing when its knocking or lowering the boost.... Live and learn LOL....
This threads kinda nostalgic...I did love that car.... I traded it for a truck after it blew a headgasket... and lost track of it....T-tops on those years sucked though
Octane, as for our cars, was also very important on those old 301t's and good fuel wasn't as abundant back then as is now. Imagine driving your GN on 87 octane and trying to race...or even 89. I'm sure you get the picture and thats what alot of guys tried to do with these cars so naturally in that aspect they ran like crap because the computer limited boost and pulled timing like our cars. Generally if you were smart you filled up with the highest octane you could find added a couple bottles of octane booster if you knew you were going to get on it. I was young and didn't know crap about the car but had a older friend that was a pretty knowlegable mechanic and racer that helped me out and learned me about detonation etc...
Back then several people were suprised at how well my car ran as 301t's had a pretty bad rep.
Eventually I ended up having some computer problems or something and my mechanic talked me into taking all the computer crap off and putting a regular distributor in it etc.. Long story short.. this was a lot harder mod than he thought it would be and had the car for 2 weeks getting it to run right... Anyway when I got the car back... WOW it ran better than ever..... for about a week until it blew a headgasket.... no stock computer .... no retarding the timing when its knocking or lowering the boost.... Live and learn LOL....
This threads kinda nostalgic...I did love that car.... I traded it for a truck after it blew a headgasket... and lost track of it....T-tops on those years sucked though
mr.turbota
New Member
- Joined
- Nov 24, 2004
If you are talking stock cars, 6.6 vs. 4.9T, chances are, it will be the stock 6.6
However, that's not always the case.
The stock 4.9T was a heavy car, the heaviest Trans Am yet for the second gens. But, the 301Ts got the 3:08 rear end gears.
However, bad points.
The turbo has the world's smallest oil cooling lines! They heat up fast. Very fast! Let them cool down, before shutting them down.
Lot's of turbo lag, at least, compared to the 3.8T!
Computer crap. I heard that you cannot find new, so junk yarding is a must.
I had my 301 Turbo rebuilt (just the turbo) 3 times already! And the car only has around 80,000 miles! I use to get it done for $150! Not now, much, much more!
Good points.
As mentioned, the 3:08 rear!
Most come with the WS-6, which with that setup, you can keep up, if not, pass others in the twisties!
Sharp looking cars!
Now, since you are talking about the 6.6 auto, that means just the Olds 403! The only Pontiac 6.6, was the W-72 in 1979, which was the 400 4 speed.
I have one of these too, and they are a blast to drive, even if they have less horsepower (185 vs. 210).
Bad points.
Most had the 2;43s, some had 2:73s.
Alot of them came without the WS-6, so no posi, big sway bars, etc.
Good points.
Could smoke any car from the same year (can't do that with the 301 Turbo, as the Vettes had the 350 still!)
Easy to find parts, compared to the 301T. At least, GM parts.
No turbo to rebuild all the time.
Now, not alot of mods to do with the 301T. I had NOS installed. Scared lots of people, since it could do nasty burnouts from a dead stop! No more turbo lag, however, even when rolling at slow speed, would fry the tires! Can't swap other engine parts (with other Pontiac engines). No head swaps, no bracket swaps, since the AC units changed. No intake swaps.
But, the 403, you can swap lots of things.
I did a 3:08 rear change (big difference-now do burnouts all day long!).
True duals, pick up power. Can't do that with a 301T.
Change heads with other Olds engines. The popular is the 350 head swap.
Heck, you can even do header swaps.
While the 403 was used for 3 years in the Trans Am, and the 301T only two years, the Olds 403 was used alot by Olds. So, lots of parts!
Heck, even the aftermarket has alumi heads for this engine! Not for the 301T.
I own all three of the cars (301T, 403 Olds, and the 3.8T), and I love them all!
But, I would get another 403 before I got another 301T, unless it was a collector's version (NASCAR Edition, Indy Edition).
But, the final choice is yours. Do what you can afford. You will have fun with either.
George
However, that's not always the case.
The stock 4.9T was a heavy car, the heaviest Trans Am yet for the second gens. But, the 301Ts got the 3:08 rear end gears.
However, bad points.
The turbo has the world's smallest oil cooling lines! They heat up fast. Very fast! Let them cool down, before shutting them down.
Lot's of turbo lag, at least, compared to the 3.8T!
Computer crap. I heard that you cannot find new, so junk yarding is a must.
I had my 301 Turbo rebuilt (just the turbo) 3 times already! And the car only has around 80,000 miles! I use to get it done for $150! Not now, much, much more!
Good points.
As mentioned, the 3:08 rear!
Most come with the WS-6, which with that setup, you can keep up, if not, pass others in the twisties!
Sharp looking cars!
Now, since you are talking about the 6.6 auto, that means just the Olds 403! The only Pontiac 6.6, was the W-72 in 1979, which was the 400 4 speed.
I have one of these too, and they are a blast to drive, even if they have less horsepower (185 vs. 210).
Bad points.
Most had the 2;43s, some had 2:73s.
Alot of them came without the WS-6, so no posi, big sway bars, etc.
Good points.
Could smoke any car from the same year (can't do that with the 301 Turbo, as the Vettes had the 350 still!)
Easy to find parts, compared to the 301T. At least, GM parts.
No turbo to rebuild all the time.
Now, not alot of mods to do with the 301T. I had NOS installed. Scared lots of people, since it could do nasty burnouts from a dead stop! No more turbo lag, however, even when rolling at slow speed, would fry the tires! Can't swap other engine parts (with other Pontiac engines). No head swaps, no bracket swaps, since the AC units changed. No intake swaps.
But, the 403, you can swap lots of things.
I did a 3:08 rear change (big difference-now do burnouts all day long!).
True duals, pick up power. Can't do that with a 301T.
Change heads with other Olds engines. The popular is the 350 head swap.
Heck, you can even do header swaps.
While the 403 was used for 3 years in the Trans Am, and the 301T only two years, the Olds 403 was used alot by Olds. So, lots of parts!
Heck, even the aftermarket has alumi heads for this engine! Not for the 301T.
I own all three of the cars (301T, 403 Olds, and the 3.8T), and I love them all!
But, I would get another 403 before I got another 301T, unless it was a collector's version (NASCAR Edition, Indy Edition).
But, the final choice is yours. Do what you can afford. You will have fun with either.
George
turbot2496
New Member
- Joined
- Mar 16, 2003
Nice collection George....Sounds unanimous then 6.6 would be the best bet.... Good luck with the purchase and .... stay away from the t-top cars.
You could get the Pontiac 6.6 l too. The standard 6.6 was the Olds and the 'TA 6.6" as shown on the shakers were Pontiacs.. I have seen many 6.6 Pontiacs with automatics..
mr.turbota said:If you are talking stock cars, 6.6 vs. 4.9T, chances are, it will be the stock 6.6
However, that's not always the case.
The stock 4.9T was a heavy car, the heaviest Trans Am yet for the second gens. But, the 301Ts got the 3:08 rear end gears.
However, bad points.
The turbo has the world's smallest oil cooling lines! They heat up fast. Very fast! Let them cool down, before shutting them down.
Lot's of turbo lag, at least, compared to the 3.8T!
Computer crap. I heard that you cannot find new, so junk yarding is a must.
I had my 301 Turbo rebuilt (just the turbo) 3 times already! And the car only has around 80,000 miles! I use to get it done for $150! Not now, much, much more!
Good points.
As mentioned, the 3:08 rear!
Most come with the WS-6, which with that setup, you can keep up, if not, pass others in the twisties!
Sharp looking cars!
Now, since you are talking about the 6.6 auto, that means just the Olds 403! The only Pontiac 6.6, was the W-72 in 1979, which was the 400 4 speed.
I have one of these too, and they are a blast to drive, even if they have less horsepower (185 vs. 210).
Bad points.
Most had the 2;43s, some had 2:73s.
Alot of them came without the WS-6, so no posi, big sway bars, etc.
Good points.
Could smoke any car from the same year (can't do that with the 301 Turbo, as the Vettes had the 350 still!)
Easy to find parts, compared to the 301T. At least, GM parts.
No turbo to rebuild all the time.
Now, not alot of mods to do with the 301T. I had NOS installed. Scared lots of people, since it could do nasty burnouts from a dead stop! No more turbo lag, however, even when rolling at slow speed, would fry the tires! Can't swap other engine parts (with other Pontiac engines). No head swaps, no bracket swaps, since the AC units changed. No intake swaps.
But, the 403, you can swap lots of things.
I did a 3:08 rear change (big difference-now do burnouts all day long!).
True duals, pick up power. Can't do that with a 301T.
Change heads with other Olds engines. The popular is the 350 head swap.
Heck, you can even do header swaps.
While the 403 was used for 3 years in the Trans Am, and the 301T only two years, the Olds 403 was used alot by Olds. So, lots of parts!
Heck, even the aftermarket has alumi heads for this engine! Not for the 301T.
I own all three of the cars (301T, 403 Olds, and the 3.8T), and I love them all!
But, I would get another 403 before I got another 301T, unless it was a collector's version (NASCAR Edition, Indy Edition).
But, the final choice is yours. Do what you can afford. You will have fun with either.
George
My personal opinion..........
Buy a '77-'78 400 4spd car.
They are rather plentiful compared to alot of the other TA's
If it has a chevy engine, don't even concider it unless there are plenty of 9 second timeslips to go with it as most TA's with chevy engines were done by idiots that blew up the Pontiac by trying to rev it to 7,000 rpm. Hybrids of this sort are wortheless
As for the 301T engine, it was nothing to write home about. Face it, it was a carb'd V8 with no intercooler. They had the right idea, but were ahead of their time.
The 403 Olds cars ran pretty good and could be modded pretty easily also, but why? It is a Pontiac with an Olds engine.
'77-'78 Pontiac 400 TA's are the way to go (unless you can find a nice early 70's TA for a descent price). There are tons of parts available for them and they are reasonably priced. The '79s' were the last of the "true pontiac engines" but you are looking for a 10th Anniversary 4 speed car and will pay through the nose for it.
If you are looking for a fun car and don't mind wheather it is original or not, find a '81 turbo car and put a 400 or 455 in it. They improved the suspension in '81 along with the 4 wheel discs on the turbo's (WS6 option) so they make for great cruisers that can run good also. You can find Turbo cars all day long that have been converted to NA for cheap.
Buy a '77-'78 400 4spd car.
They are rather plentiful compared to alot of the other TA's
If it has a chevy engine, don't even concider it unless there are plenty of 9 second timeslips to go with it as most TA's with chevy engines were done by idiots that blew up the Pontiac by trying to rev it to 7,000 rpm. Hybrids of this sort are wortheless
As for the 301T engine, it was nothing to write home about. Face it, it was a carb'd V8 with no intercooler. They had the right idea, but were ahead of their time.
The 403 Olds cars ran pretty good and could be modded pretty easily also, but why? It is a Pontiac with an Olds engine.
'77-'78 Pontiac 400 TA's are the way to go (unless you can find a nice early 70's TA for a descent price). There are tons of parts available for them and they are reasonably priced. The '79s' were the last of the "true pontiac engines" but you are looking for a 10th Anniversary 4 speed car and will pay through the nose for it.
If you are looking for a fun car and don't mind wheather it is original or not, find a '81 turbo car and put a 400 or 455 in it. They improved the suspension in '81 along with the 4 wheel discs on the turbo's (WS6 option) so they make for great cruisers that can run good also. You can find Turbo cars all day long that have been converted to NA for cheap.
turbot2496
New Member
- Joined
- Mar 16, 2003
Ooooh man now were talking.... or how about just swapping in the turbo 3.8.... after all we are in a buick forum mr.turbota
New Member
- Joined
- Nov 24, 2004
Funny you should mention that!
The base Firebird in 1981, came with the Buick 3.8 liter engine!
Guess what? The same motor mounts! HeHe!
I have been thinking that with my 1981 Turbo Trans Am!
Oh ya, and another thing, Pontiac stopped making the 400 in 1978. All 1979 400s were leftovers, and all came with the 4-speed. Also known as the W-72 option. The regular 400s of '77-'78 years were also know as the 6.6 liter engines. The W-72s had more power, and could be differated by the chrome valve covers. But again, people change things. Just like changing the hoodscoop decals. All the decal repro shops sell the TA6.6, which is the W-72 version. Like I said, the regular 400 was known as the 6.6 liter, just like the Olds 403.
Confused? I hope not.
Hope this helps,
George
The base Firebird in 1981, came with the Buick 3.8 liter engine!
Guess what? The same motor mounts! HeHe!
I have been thinking that with my 1981 Turbo Trans Am!
Oh ya, and another thing, Pontiac stopped making the 400 in 1978. All 1979 400s were leftovers, and all came with the 4-speed. Also known as the W-72 option. The regular 400s of '77-'78 years were also know as the 6.6 liter engines. The W-72s had more power, and could be differated by the chrome valve covers. But again, people change things. Just like changing the hoodscoop decals. All the decal repro shops sell the TA6.6, which is the W-72 version. Like I said, the regular 400 was known as the 6.6 liter, just like the Olds 403.
Confused? I hope not.
Hope this helps,
George
turbot2496
New Member
- Joined
- Mar 16, 2003
uuuughhhh... Now you got my gears turning too, but I already have one project I haved to get done....that would be so cool though.... I loved that body style
Why exactly was the 4.9t TA so heavy anyway and can it be remedied?
Why exactly was the 4.9t TA so heavy anyway and can it be remedied?
They made cars back then out of real steelturbot2496 said:
I don't think the 4.9 was any heavier than any other f-body back then, they were all heavy as heck.Here's a link to all the 2-gen info you could ever want to read, year by year what the changes and engine combos were.... BTW, the 4.9 turbo motors had a higher hp rating than the 6.6 Pontiac motors of the late 70's. Most 4.9s run like crap because of high detonation on todays crappy gas and poor tune, thats why most blow the headgaskets easily...also, the 4.9 short block cannot handle any added power once mods start, so the 400 Pontiac is a much better platform.
http://www.iwaynet.net/~gl&lisk/transam.html
turbot2496
New Member
- Joined
- Mar 16, 2003
George said the 4.9t was the heaviest and since he owns all three flavors I figure he knows what he's talking about. I guess the hood and maybe all the turbo crap made the difference. That website says it weighed 3717# and the 79 weighed 3700#. 17# difference sound right? Heavy but workable..... have to put it on a diet. 3.8 would shed a few pounds of it. LOL
Would be a cool sleeper......
Would be a cool sleeper......
