Dyno results on BB...
Thread Starter
Instructor
Joined: Feb 2001
Posts: 217
Likes: 1
From: Suwanee GA
Dyno results on BB...
OK, no super results, but I thought I would post them anyway for others out there with similar setups to mine:
Engine is a fairly mild 433 with a hyd cam (.527/.553, 224/232 @ .050), 9:1, oval ports with 2.19 valves, air gap, 750 cfm dp, headers, MSD 6A.
Dyno 2 years ago, same as above but Torker II intake, stock mufflers: 283 hp and 333 ft lbs.
Dyno last year with new exhaust with cross over, Super Turbos, Air Gap dual plane intake, 333 hp, 388 ft lbs.
Dyno today as baseline. Only change from last year is leaned carb a little, backed off timing to 32 total, 335 hp, 388 ftlbs.
After 6 runs, best power was based on: Bumped timing to 38 total, disconnected vacuum advance, changed jets from 76/82 to 76/84: 346.3 hp, 402.6 ft lbs torque (5000 rpm, and 3800 rpm).
I thought I would find more power, but at least I was able to confirm my optimum A/F ratio and timing. The engine feels much better on the bottom end and midrange. I thought the hp peak would be higher and at a higher rpm. Next motor will have more cam and more compression.
Btw, A/F ratio was on the lean side at part throttle, at WOT, it went to 11.6 (2600 rpm-3200 rpm), was at 12.0 (3300-3700), between 12.5 and 13.0 (3800-5300 rpm).
Engine is a fairly mild 433 with a hyd cam (.527/.553, 224/232 @ .050), 9:1, oval ports with 2.19 valves, air gap, 750 cfm dp, headers, MSD 6A.
Dyno 2 years ago, same as above but Torker II intake, stock mufflers: 283 hp and 333 ft lbs.
Dyno last year with new exhaust with cross over, Super Turbos, Air Gap dual plane intake, 333 hp, 388 ft lbs.
Dyno today as baseline. Only change from last year is leaned carb a little, backed off timing to 32 total, 335 hp, 388 ftlbs.
After 6 runs, best power was based on: Bumped timing to 38 total, disconnected vacuum advance, changed jets from 76/82 to 76/84: 346.3 hp, 402.6 ft lbs torque (5000 rpm, and 3800 rpm).
I thought I would find more power, but at least I was able to confirm my optimum A/F ratio and timing. The engine feels much better on the bottom end and midrange. I thought the hp peak would be higher and at a higher rpm. Next motor will have more cam and more compression.
Btw, A/F ratio was on the lean side at part throttle, at WOT, it went to 11.6 (2600 rpm-3200 rpm), was at 12.0 (3300-3700), between 12.5 and 13.0 (3800-5300 rpm).
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Dyno results on BB... (Doug Brandon)
Would be interested in seeing your graph for your first and last runs. Since you say you feel more power down low I am curious in how much ave torque you gained between 2000 and 4000 rpm's where most city driving is done. I beginning to believe for everyday fun more torq is my friend. :yesnod:
BTW I bet that your car is fun to drive based on those power figures. :thumbs:
[Modified by Fevre, 11:10 PM 7/11/2003]
BTW I bet that your car is fun to drive based on those power figures. :thumbs:
[Modified by Fevre, 11:10 PM 7/11/2003]
Le Mans Master
Joined: Sep 2000
Posts: 9,078
Likes: 7
From: DFW TX
Cruise-In VII Veteran
St. Jude Donor '07
Re: Dyno results on BB... (Fevre)
Now that's some good numbers. I would be very happy. 400+ torque would pull the front tires in most cars. Hp just gets you there, torque makes you fly. :cheers:
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Dyno results on BB... (Doug Brandon)
Doug,
I think those are very good numbers! Most people don't realize how much power they leave untapped until they get their car correctly tuned. I've been there myself. For a mild cam and low compression, you made numbers very close to a factory high compression L71 or LS6 Big Block.
Chuck
I think those are very good numbers! Most people don't realize how much power they leave untapped until they get their car correctly tuned. I've been there myself. For a mild cam and low compression, you made numbers very close to a factory high compression L71 or LS6 Big Block.
Chuck
Thread Starter
Instructor
Joined: Feb 2001
Posts: 217
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From: Suwanee GA
Re: Dyno results on BB... (ORVette)
Appreciate the feedback-
On the first pull torque was 340 ftlb @2300 rpm and stayed above there until 5200 rpm. The last pull torque was 360 ftlb @2300. It was above 390 from 3300 rpm until 4500 rpm. Nice and flat. I think the timing changes helped a lot.
My goal has always been to have sort of a poor man's LS6 (especially since it is a '71). If I come across a good original intake, I may build my next motor along those lines, but with more compression and go with GMPP alum heads. Just have to wonder how much hp that intake costs.
The cam is ground on a 114 LSA. It idles at 800 with around 13 inches of vacuum. And it is fun to drive with the 4 speed and 3.36 gears, but you always want more!
On the first pull torque was 340 ftlb @2300 rpm and stayed above there until 5200 rpm. The last pull torque was 360 ftlb @2300. It was above 390 from 3300 rpm until 4500 rpm. Nice and flat. I think the timing changes helped a lot.
My goal has always been to have sort of a poor man's LS6 (especially since it is a '71). If I come across a good original intake, I may build my next motor along those lines, but with more compression and go with GMPP alum heads. Just have to wonder how much hp that intake costs.
The cam is ground on a 114 LSA. It idles at 800 with around 13 inches of vacuum. And it is fun to drive with the 4 speed and 3.36 gears, but you always want more!
Senior Member since 1492
Joined: Aug 2000
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Re: Dyno results on BB... (Doug Brandon)
For RWHP/TQ that is impressive. I'm hoping for similar results using GMPP Al-heads 2.25valves, a little stronger cam 0.595 lift and LS6 pistons. :thumbs: :chevy
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Safety Car
Joined: Oct 2000
Posts: 4,080
Likes: 565
From: Allen TX
Re: Dyno results on BB... (Lasse)
Your dyno results are right in line with what I got...and mine is just a tad milder than yours.
334rwhp/384rwtq
454HO crate with 8.75:1 CR, GM iron heads, 211/230 cam, low rise LS6 intake, headers, 770cfm carb. My A/F ratio was 13.0:1 across the board, and also made over 370rwtq from 1900-4300rpm.
Hoping to have my new mods all buttoned up by the end of next week. :)
It's good to hear results from other combos, so thanks for posting!
334rwhp/384rwtq
454HO crate with 8.75:1 CR, GM iron heads, 211/230 cam, low rise LS6 intake, headers, 770cfm carb. My A/F ratio was 13.0:1 across the board, and also made over 370rwtq from 1900-4300rpm.
Hoping to have my new mods all buttoned up by the end of next week. :)
It's good to hear results from other combos, so thanks for posting!
Thread Starter
Instructor
Joined: Feb 2001
Posts: 217
Likes: 1
From: Suwanee GA
Re: Dyno results on BB... (WA 2 FST)
I feel like I finally cracked the code on mine. I have driven it twice today, each time backing off the size of the shooter to help an off idle miss. Finally got it right. Car is running far better than it ever has. I think plugging my vacuum advance and tuning around that set up has really helped (20 initial, 38 total). Car will bust loose the tires now from a rolling start in first gear. Could not do that before. The 2 bills I spent yesterday on the dyno were well worth it.
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Re: Dyno results on BB... (Doug Brandon)
Hi Doug,
Nice results! I figured there was some more left w/ some carb tuning! I think you have definitely got your money's worth on the dyno runs, gained torque, HP while learning something about your combination -- what's not to like?!?
I've also found aggressive timing curves make a big difference, espcecially w/ off idle throttle response. Sounds like you're very close to that often elusive, but oh so satisfying killer tune!
Take care,
Mark
Nice results! I figured there was some more left w/ some carb tuning! I think you have definitely got your money's worth on the dyno runs, gained torque, HP while learning something about your combination -- what's not to like?!?
I've also found aggressive timing curves make a big difference, espcecially w/ off idle throttle response. Sounds like you're very close to that often elusive, but oh so satisfying killer tune!
Take care,
Mark
