Ken Duttweiler's Hot Air

[cwmccray]

I finally got my server to come back up. I found this article from HOT ROD on Ken Duttweiler and then editor, John Baechtel's Regal P/SA Stocker. This was a 12.74@106 Hot Air in 1985. If read the article carefully, you will see how amazing this was.

On 17lbs of boost, it produced 364hp and 460ft lbs of torque. He raised the boost to 30lbs and was rewarded with 410hp and 539ft lbs of torque. This was in 1985 . Amazingly he did not blow any headgaskets, but the car did not run any faster .

NHRA was so impressed with car it move the car up 4 classes to M/SA. It also refactored hp from 200 to 225. From the factory this was closer to being the Hot Airs real hp numbers.

Any one with a Hot Air knows that you are running on low boost 8-10lbs of boost, if you are lucky . If you make repeated runs, you WILL lose 2-3lbs of boost .

Duttweiler learned his trade in a Hot Air. From what we know now, he made a huge mistake with gears, 4.56. He also had Turbo 350 tranny with a 10 inch Convertor. He also fabbed headers and a 3" downpipe. He developed the Crane Cheater Cam, 206/206. Other than this, the car was stock! I suspect 4.56 gear made the car stumble as it did. Also, I suspect that 4.56 would make the turbo overspeed itself. The cam shaft moved the powerband up . Amazingly with all this wrong, the car ran 12's in 1985. Ooops, I forgot, he was using the stock chip . Hot Air cars are tempermental, which he found out. In 1986, Buick changed the intake and put in a Intercooler and this changed EVERYTHING .

Assuming that the 10inch convertor slipped, 364hp should have got the car in the 12.40s. 30lbs of boostand 410hp should have got the car in the 11.60 or better range. Brent, Eric Singer, and others running mid 11's are laying down 400+ hp. Amazingly Ms. Jamie and Leeo, both had their hp over 500hp .

Sorry for such a long post, but I thought this was VERY interesting considering before intercoolers became the norm....:

 

[VKREGAL]

cool article

 

[1dollardog]

A 4.56? Would anyone, given modern knowledge of these cars run a 4.56 in any GN these days. And no OD? I wander what he set as red line on the tach? I'd bet it was in the red line well before the end of the track. Amazing what HP he and others got from the hot air cars in 1985. It should be cheaper and easier to make that kind of HP now-a-days...Right!!!! I'd bet that car pissed alot of big block guys off back then. Great article. I probably read that article back then but then again I was only 14 in '85.

 

[cwmccray]

I was just getting my licence. By the time I graduated in 86, I knew I had to have one. The 84-85 Hot Airs were killers against L69 Z's and T/A's. In 1986, EVERYTHING changed. The Buick became a legend on the Street.

 

[dr_frankenstein]

A 4.56? Would anyone, given modern knowledge of these cars run a 4.56 in any GN these days. And no OD? I wander what he set as red line on the tach? I'd bet it was in the red line well before the end of the track. Amazing what HP he and others got from the hot air cars in 1985. It should be cheaper and easier to make that kind of HP now-a-days...Right!!!! I'd bet that car pissed alot of big block guys off back then. Great article. I probably read that article back then but then again I was only 14 in '85.

Not a GN but a truck.

I did it for 6 months. 6500 rpm was like hmm......... barely 75mph with a 26" tall tire.

I swapped to 3.73s about 3 weeks ago....... still sucks. but 75 is now around 4400 to 4500 with a 28" tire. makes much much more power though.

I tell ya though, the 1-2 shift with those 4.56 gears was a tire ripping punch! its still a good healthy bark now with the 3.73s.

LOL, yea its not a good idea to run the high gears.... 4500+ for an extended period of time tends to make the engine leak!

A.j.

 

[esinger]

. Brent, Eric Singer, and others running mid 11's are laying down 400+ hp. Amazingly Ms. Jamie and Leeo, both had their hp over 500hp .

That's fine company you are putting me with, but I'm not quite a 11 second car yet. If I ever ran the 1/4 I think I'd be very, very low 12's but not mid 11's.

I didn't know all this info about Ken Duttweiler. Very interesting and thanks for sharing.

 

[cwmccray]

I would guess with 4.56, the car might have done well in the 1/8 mile. But by the end of the 1/4, it would be out of breath... If you were lucky, your boost gauge would read 10 lbs. from the factory.

With todays standards, it would be easy to get a Hot Air in the 12s. Everyone would agree that the header and downpipe are issues. Removing the restrictive exhaust system would improve the power potential. The 84-85 chip select is not good, thus changing to the 86-87 computer and chip. The stock turbo will stop making power close to the 400hp mark. The injectors will start to hinder below the 400hp mark. 300-330hp will get you solidly into the 12 sec zone.

Look at it this way for Ms. Jamie (TURBO6X2) to get into the 10 sec club, she had to atleast be making 500-525hp.... with less cubes (231 vs 252) than Leeo. Interestingly enough, I curious to know what extactly in the intercooler worth. I am going to use a 87 intake on my car. I will be able to change from Hot to Cooled in a minutes.

 

[turbofish38]

I bet the reason he ran those gears and the THM350 was because there were no HD or Race parts for the 200-4R back in 84-85. The THM200-4R was only 3 years old back in 84. Figure in the 2.48 lowgear with that ratio and tall slicks and it's not that big of a mistake. He obviously was taking atvantage of the off the line torque these motors made. Heck even a 14 second Stock Eliminator pulls the front wheels up on a launch.

I remember that article. Every time somebody brings up modifying the intake manifold this article should be linked. Only to prove that the stock part performs quite well up into those times that Duttweiler was turning.

 

[novaderrik]

is that the stock elbow on the turbo?

 

[turbo2nr]

A 4.56? Would anyone, given modern knowledge of these cars run a 4.56 in any GN these days.




I'm pretty sure that the Gallinas run something like that in wife's car.....
I think they know what to do Could we all be wrong?? Don't argue with me...argue with their trophy for winning.

 

[1dollardog]

A 4.56? Would anyone, given modern knowledge of these cars run a 4.56 in any GN these days.




I'm pretty sure that the Gallinas run something like that in wife's car.....
I think they know what to do Could we all be wrong?? Don't argue with me...argue with their trophy for winning.

No arguments here. The numbers speak for themselves. It just goes against everything I "thought" I knew and had learned from other TR owners about gear ratio/tranny combinations for these cars. I have read however in many posts by members with much more experence than myself that the 3.42 was one of the few things that GM got exactly right on these cars. However a 12.74@106 speaks for its self .

 

[cwmccray]

With a tall 9inch Firestone Slick, I could imagine the 4.56's acting like 3.90 or 4.10's. We could understand the Turbo350 also due to the fact that Art Carr and others really did not develop the 200R4 until after the 86 model hit the streets. Buick already had beefed up the tranny from the factory due to the intake and intercooler change.

The article is vague about the fuel system. We can determine that is was stock. I could ASSume that either the regulator was adjustable or crushed to increase pressure. Duttweiler cleaned the heads up: ported, valve job. The cam was the Crane 206/206. This cam move the power band up.

The turbo was the factory turbo. It had been blueprinted and checked for seal leaks.

We can only imagine if the 3.42's had been left instead of 4.56's. I can only ASSume that Duttweiler figured out that he needed to re calibrate the chip to get the car to run with all the changes made.

1986 changed everthing. Buick solved Duttweiler's issues. He took a 85 T Type from a 15 to a 12sec car. Buick had the 86 model already in the mid to low 14 sec range. Due to the intercooler, he had a advantage of boosting higher. The tranny had firm shifts due to new servo and pressure reg. Only thing to do was to put boost to it.

In hindsight, most great tuners have started with Hot Air cars. Everything is critical in a Hot Air.

 

[turbo2nr]

No arguments here. The numbers speak for themselves. It just goes against everything I "thought" I knew and had learned from other TR owners about gear ratio/tranny combinations for these cars. I have read however in many posts by members with much more experence than myself that the 3.42 was one of the few things that GM got exactly right on these cars. However a 12.74@106 speaks for its self .

I believe it does with many 1st place finishes.

If you can do better following the rules of the class at the time, than go for it!

4.56 was winning back then, and it is still used by the Pros. Go figure??

 

[Jerryl]

With a tall 9inch Firestone Slick, I could imagine the 4.56's acting like 3.90 or 4.10's. We could understand the Turbo350 also due to the fact that Art Carr and others really did not develop the 200R4 until after the 86 model hit the streets. ...........

First off, thanks for sharing the article.

I full agree with what you are saying and think you have the work “the perfect ratio” backwards through calcs and then adjust to “real life” data;
So, if the motor is set-up for 5000 rpm (example), you want to calculate the MPH/converter slip/tire dia/trans ratio and see which rear end ratio you need.
Now, if you are unable to pull the lower differential gears to get to the target rpm, you need other ones, or tires, etc.

For 1/8 vs ¼ mile, the ratio’s will/should be different on a tack only car.

Edit; :tongue:
I am taking NOTHING away from the incredible accomplishments of KD.
But putting a HA in the 12’s with today's tech is not near as impossible as it ones seemed.
IMHO, for a HA car, the TT chip tech and PAC pull it all together, race gas or not.

 

[KevinB]

A 4.56? Would anyone, given modern knowledge of these cars run a 4.56 in any GN these days.




I'm pretty sure that the Gallinas run something like that in wife's car.....
I think they know what to do Could we all be wrong?? Don't argue with me...argue with their trophy for winning.

That car is now in Dayton, OH and has an intercooler setup on it now. The attention to detail on that car is crazy. The car was running ATR like headers in hot air mode. Neat setup for sure. I'm not sure of the gear ratio but the car did have 31" tall tires on it if I remember correctly.

 

[Spooled231]

That car is now in Dayton, OH and has an intercooler setup on it now. The attention to detail on that car is crazy. The car was running ATR like headers in hot air mode. Neat setup for sure. I'm not sure of the gear ratio but the car did have 31" tall tires on it if I remember correctly.

KevinB,

I must agree the attention to detail of the setup is wild. I got a chance to drive the car at BPG in August 2008 and the vacuum brakes would hold like no other at 20psi on the foot brake itself! The slicks on the back are a 30x9 M/T radial slick with a 4.10 I believe. I wouldnt be a bit suprised if there's a 4.30 or 4.56 gear in the car.

If things go to plan, I will be making BPG rather than BG this year and will be driving the car again for Tom.

John Martin
1986 Buick T-Type
9.71 @ 140

 

[KevinB]

KevinB,

I must agree the attention to detail of the setup is wild. I got a chance to drive the car at BPG in August 2008 and the vacuum brakes would hold like no other at 20psi on the foot brake itself! The slicks on the back are a 30x9 M/T radial slick with a 4.10 I believe. I wouldnt be a bit suprised if there's a 4.30 or 4.56 gear in the car.

If things go to plan, I will be making BPG rather than BG this year and will be driving the car again for Tom.

John Martin
1986 Buick T-Type
9.71 @ 140

Awesome! See ya there. Don't forget the HANS device

 

[blown okie]

i talked with Vic guilmino about his intercooled TR he used to run in stock eliminator.. he used a 5.xx gear, used a beefedd 200r4 & USED OVERDRIVE!! & locked the converter!! he said it worked very well even when people told him it wouldn't.. Brian @ gbody parts has this car now.. maybe he will chime in.. speaking of which i need to call him...

 

[blown okie]

also i actually found the issue of hot rod with the article posted above in my ever growing library .. i also have several hot rod, car craft, super stock & drag illustrated when they tested the hot air & intercooled cars when they were new... just wish i was a little older when these cars were new.. oh well...

 

[turbo6x2]

Look at it this way for Ms. Jamie (TURBO6X2) to get into the 10 sec club, she had to atleast be making 500-525hp.... with less cubes (231 vs 252) than Leeo. Interestingly enough, I curious to know what extactly in the intercooler worth. I am going to use a 87 intake on my car. I will be able to change from Hot to Cooled in a minutes.[/QUOTE]

At least