Chassis dyno results
Thread Starter
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Chassis dyno results
Also posted on the C1 & C2 forum.
Today I went to New England Dyno and Tuning in Worcester, MA with 3 of my friends and we dyno'd our cars on a Dynojet chassis dyno. We had a blast! And we all gained HP & torque over the course of several pulls.
My first pull yielded 537 HP @ 6300 and 524 lb-ft @ 4700. One of my friends noticed my fuel pressure dropped to ~ 3.5 psi, so I bumped my pressure to 7.5 psi. The 2nd pull yielded 539 HP and 538 lb-ft and my fuel pressure maintained a minimum of 5 psi throughout the pull. Unfortunately my A/F ratio (NEDT has a wideband O2 sensor) showed a lean condition (~ 14:1), so I increased my jet size from 84 to 86 on both sides. My 3rd pull yielded 549 HP and 533 lb-ft, but my A/F was still lean. I then increased my jets to 90 front & back. My 4th and final pull yielded 560 HP and 550 lb-ft -- and my fuel curve was still on the lean side (13.8:1)! Please see the graph of my last pull below:
As you can see I'm still on the lean side of the desirable 12.7:1 to 13.1:1 normally aspirated A/F sweet spot.
We all had fun. We all got to drive our cars on the dyno. I’ve got to say it was quite an experience just sitting there winding my big block to 6500 RPM, hoping things would stay together! The shriek of a well running Vette on a dyno in an enclosed space should be experienced by every Vette owner! My friend Nick in a nice 70 Chevelle SS got 422 HP @ 5300 and 441 lb-ft @ 4300 on his best run. My friend Matt in an equally nice 70 Buick GSX Stage 1 pulled 421 HP @ 6400 and more than 496 lb-ft @ 3200. I say “more than” as Matt was the only one w/ an automatic transmission, and had to have enough rpm to keep from downshifting. His torque curve was dropping the entire recorded rpm range, suggesting his peak was at an rpm below the speed he started his pull. Matt squeezed the NOS button on his last pull and jumped to 500 HP and 560 lb-ft. The 4th friend, Ray, drove a new Celica, and gained ~ 12 HP with an aftermarket induction tube over his stock baseline. The only unfortunate part of the day was another friend in a 64 Corvette w/ 502, ROD 6-speed, NOS and functional AC was unable to attend.
If you have the opportunity to (chassis) dyno your car, I strongly recommend it. It will be fun, you’ll learn something about your car‘s state of tune, and will likely gain HP. Unfortunately we don’t have video of the days activities, but I will be posting pictures later.
Take care,
Mark
Today I went to New England Dyno and Tuning in Worcester, MA with 3 of my friends and we dyno'd our cars on a Dynojet chassis dyno. We had a blast! And we all gained HP & torque over the course of several pulls.
My first pull yielded 537 HP @ 6300 and 524 lb-ft @ 4700. One of my friends noticed my fuel pressure dropped to ~ 3.5 psi, so I bumped my pressure to 7.5 psi. The 2nd pull yielded 539 HP and 538 lb-ft and my fuel pressure maintained a minimum of 5 psi throughout the pull. Unfortunately my A/F ratio (NEDT has a wideband O2 sensor) showed a lean condition (~ 14:1), so I increased my jet size from 84 to 86 on both sides. My 3rd pull yielded 549 HP and 533 lb-ft, but my A/F was still lean. I then increased my jets to 90 front & back. My 4th and final pull yielded 560 HP and 550 lb-ft -- and my fuel curve was still on the lean side (13.8:1)! Please see the graph of my last pull below:
As you can see I'm still on the lean side of the desirable 12.7:1 to 13.1:1 normally aspirated A/F sweet spot.
We all had fun. We all got to drive our cars on the dyno. I’ve got to say it was quite an experience just sitting there winding my big block to 6500 RPM, hoping things would stay together! The shriek of a well running Vette on a dyno in an enclosed space should be experienced by every Vette owner! My friend Nick in a nice 70 Chevelle SS got 422 HP @ 5300 and 441 lb-ft @ 4300 on his best run. My friend Matt in an equally nice 70 Buick GSX Stage 1 pulled 421 HP @ 6400 and more than 496 lb-ft @ 3200. I say “more than” as Matt was the only one w/ an automatic transmission, and had to have enough rpm to keep from downshifting. His torque curve was dropping the entire recorded rpm range, suggesting his peak was at an rpm below the speed he started his pull. Matt squeezed the NOS button on his last pull and jumped to 500 HP and 560 lb-ft. The 4th friend, Ray, drove a new Celica, and gained ~ 12 HP with an aftermarket induction tube over his stock baseline. The only unfortunate part of the day was another friend in a 64 Corvette w/ 502, ROD 6-speed, NOS and functional AC was unable to attend.
If you have the opportunity to (chassis) dyno your car, I strongly recommend it. It will be fun, you’ll learn something about your car‘s state of tune, and will likely gain HP. Unfortunately we don’t have video of the days activities, but I will be posting pictures later.
Take care,
Mark
Thread Starter
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Re: Chassis dyno results (Steve Zaino)
I believe their nominal price is $125/hour including wideband O2 sensor. We got 4 people together and were each charged $100/hour. Although speculation on my part, you may be able to negotiate the $100/hour price for less than 4 cars.
Jeff and Dean at NEDT were great. I think the price is reasonable even at $125/hr, and you will likely find hidden horsepower. And you will definitely have fun doing it.
Take care,
Mark
Jeff and Dean at NEDT were great. I think the price is reasonable even at $125/hr, and you will likely find hidden horsepower. And you will definitely have fun doing it.
Take care,
Mark
Thread Starter
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Re: Chassis dyno results (ML67)
Chuck -- traction, what traction!?! Yeah it doesn't exactly hook up, but it certainly adds to the pucker factor! BTW nice ride yourself. If you don't mind, could you let me know how you recorded and subsequently posted your sound file? Thanks for the kind words.
Steve -- http://www.dynojet.com/lauto.shtml Good luck!
Ravens -- It *is* fun driving it!. If you ever make up to NH, I'll be glad to drive you to the snowball stand. Hey, we're in the midst of a late summer heat wave, 90 yesterday and projected to be over 80 through Tuesday. Cruising season is short enough, no need to remind me of the looming cold weather.
Take care,
Mark
Steve -- http://www.dynojet.com/lauto.shtml Good luck!
Ravens -- It *is* fun driving it!. If you ever make up to NH, I'll be glad to drive you to the snowball stand. Hey, we're in the midst of a late summer heat wave, 90 yesterday and projected to be over 80 through Tuesday. Cruising season is short enough, no need to remind me of the looming cold weather.
Take care,
Mark
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Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Chassis dyno results (ML67)
Mark,
This is an earlier post I made on making sound files. Hope it helps. I really would love to hear yours!!
http://forums.corvetteforum.com/zerothread?id=132548
Chuck
[Modified by Chuck Harmon, 9:41 AM 9/8/2001]
This is an earlier post I made on making sound files. Hope it helps. I really would love to hear yours!!
http://forums.corvetteforum.com/zerothread?id=132548
Chuck
[Modified by Chuck Harmon, 9:41 AM 9/8/2001]
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: Chassis dyno results (ML67)
It is said that "Absolute power corrupts absolutely". If so, that is one seriously corrupted '67!
Congratulations on your dyno results and for having such a fine looking machine. Your car is a well balanced package of power and beauty. :yesnod:
Congratulations on your dyno results and for having such a fine looking machine. Your car is a well balanced package of power and beauty. :yesnod:
Thread Starter
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Re: Chassis dyno results (ML67)
Chuck -- thanks! I wish I knew this before, I could've recorded the dyno fun. Now I have a good use for my work computer! I hope to get a sound file posted next week.
Miker -- thanks for the kind words. As any Vette owner knows, there's always something to fix, upgrade, replace... definitely part of the fun. My wife thinks of it less a hobby and more an obsession. Of course she's right.
As an example, I was out tuning this afternoon, having to significantly richen the main circuits and increasing fuel pressure at the dyno yesterday put my idle/transfer circuit slightly out of whack. After determining things were adjusted correctly and a few quick 6500 rpm bursts, I began my return ride. About 1 mile from my house, it starts making some ominous underhood noises. The alternator retaining bolt had backed out, thus allowing the alternator to slip out of the bracket. From the fan belt tension, it pulled the nose of the alternator down, causing the alternator fan blades to rub (more like crash) against the bracket. I think all the runs to 6600 rpm yesterday caught up to me! A small problem, but took about 45 minutes of roadside repair to limp home. Of course just to make it challenging, I inadvertantly removed my regular Vette tools along with the additional tools I brought to the dyno, so I got to fix it w/ a crescent wrench. It was HOT under the hood!
All back together, replete w/ a ding on the valve cover behind the alternator. Just when you think you've got everything right...
Take care,
Mark
Miker -- thanks for the kind words. As any Vette owner knows, there's always something to fix, upgrade, replace... definitely part of the fun. My wife thinks of it less a hobby and more an obsession. Of course she's right.
As an example, I was out tuning this afternoon, having to significantly richen the main circuits and increasing fuel pressure at the dyno yesterday put my idle/transfer circuit slightly out of whack. After determining things were adjusted correctly and a few quick 6500 rpm bursts, I began my return ride. About 1 mile from my house, it starts making some ominous underhood noises. The alternator retaining bolt had backed out, thus allowing the alternator to slip out of the bracket. From the fan belt tension, it pulled the nose of the alternator down, causing the alternator fan blades to rub (more like crash) against the bracket. I think all the runs to 6600 rpm yesterday caught up to me! A small problem, but took about 45 minutes of roadside repair to limp home. Of course just to make it challenging, I inadvertantly removed my regular Vette tools along with the additional tools I brought to the dyno, so I got to fix it w/ a crescent wrench. It was HOT under the hood!
All back together, replete w/ a ding on the valve cover behind the alternator. Just when you think you've got everything right...
Take care,
Mark
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: Chassis dyno results (ML67)
I hear ya Mark,
Older Vettes are kind of like 4-wheeled Harley's. Just gotta pick up the pieces as they fall off and keep on grinnin' :lol: You gotta expect some failures when hammering on 10 to 35+ year old cars but the overall experience is definitely worth it. :yesnod:
Older Vettes are kind of like 4-wheeled Harley's. Just gotta pick up the pieces as they fall off and keep on grinnin' :lol: You gotta expect some failures when hammering on 10 to 35+ year old cars but the overall experience is definitely worth it. :yesnod:
Miker -- thanks for the kind words. As any Vette owner knows, there's always something to fix, upgrade, replace... definitely part of the fun. My wife thinks of it less a hobby and more an obsession. Of course she's right.
As an example, I was out tuning this afternoon, having to significantly richen the main circuits and increasing fuel pressure at the dyno yesterday put my idle/transfer circuit slightly out of whack. After determining things were adjusted correctly and a few quick 6500 rpm bursts, I began my return ride. About 1 mile from my house, it starts making some ominous underhood noises. The alternator retaining bolt had backed out, thus allowing the alternator to slip out of the bracket. From the fan belt tension, it pulled the nose of the alternator down, causing the alternator fan blades to rub (more like crash) against the bracket. I think all the runs to 6600 rpm yesterday caught up to me! A small problem, but took about 45 minutes of roadside repair to limp home. Of course just to make it challenging, I inadvertantly removed my regular Vette tools along with the additional tools I brought to the dyno, so I got to fix it w/ a crescent wrench. It was HOT under the hood!
All back together, replete w/ a ding on the valve cover behind the alternator. Just when you think you've got everything right...
Take care,
Mark
As an example, I was out tuning this afternoon, having to significantly richen the main circuits and increasing fuel pressure at the dyno yesterday put my idle/transfer circuit slightly out of whack. After determining things were adjusted correctly and a few quick 6500 rpm bursts, I began my return ride. About 1 mile from my house, it starts making some ominous underhood noises. The alternator retaining bolt had backed out, thus allowing the alternator to slip out of the bracket. From the fan belt tension, it pulled the nose of the alternator down, causing the alternator fan blades to rub (more like crash) against the bracket. I think all the runs to 6600 rpm yesterday caught up to me! A small problem, but took about 45 minutes of roadside repair to limp home. Of course just to make it challenging, I inadvertantly removed my regular Vette tools along with the additional tools I brought to the dyno, so I got to fix it w/ a crescent wrench. It was HOT under the hood!
All back together, replete w/ a ding on the valve cover behind the alternator. Just when you think you've got everything right...
Take care,
Mark
Burning Brakes
Joined: Feb 2001
Posts: 854
Likes: 0
Re: Chassis dyno results (ML67)
MARK. PROBABLY "THE" BEST LOOKING 67 AROUND!! SUPER POWER. GOTTA BE A REAL KICK...... CURIOUS IF YOU HAVE EVER DB TESTED YOUR CAR. WHAT ARE THE GUIDE LINES IN YOUR STATE. EVERY STATE HAS ITS OWN IDEA WHAT THIS IS. NOTHING CONSISTANT!!! THANKS, JCL :cool: :chevy
Thread Starter
Burning Brakes
Joined: Jul 1999
Posts: 922
Likes: 164
From: Hudson NH
Re: Chassis dyno results (JCL)
Jim -- its very loud. I have a dB meter from work hanging around somewhere, I'll have to measure it again. The meter bounces around quite a bit, and is highly dependent on where the meter is held in relation to the exhaust turnout.
Seeing as I have problems getting it inspected due to the noise, I'll just assume its not legal. I regularly set off car alarms cruisng down Main Street! When I get rejected, my wife takes it in. It inevitably passes!
I've never been pulled over (for excessive noise anyway). We have quite a few Harley's in the area that run open pipes -- I've never seen them pulled over either. I drive very conservatively 98% of the time, and really pick and choose when and where I open it up. So far so good.
If you saw my car up close, you probably wouldn't think it was so nice. I've had it now for 14 years and haven't had it painted. Its starting to show wear and tear. Looks good from 10 feet away. I still have a few upgrades before I worry about paint. And even then I'm not sure if I'll have it painted. I enjoy driving it, and the last thing I want is to become paranoid about the paint. Don't get me wrong, I would like to have a nice paint job, but I'm not sure I'm ready to sacrifice the money and attendant **** TLC that invariably accompanies killer paint.
I'll post some dB readings next time I take it out.
Take care,
Mark
Seeing as I have problems getting it inspected due to the noise, I'll just assume its not legal. I regularly set off car alarms cruisng down Main Street! When I get rejected, my wife takes it in. It inevitably passes!
I've never been pulled over (for excessive noise anyway). We have quite a few Harley's in the area that run open pipes -- I've never seen them pulled over either. I drive very conservatively 98% of the time, and really pick and choose when and where I open it up. So far so good.
If you saw my car up close, you probably wouldn't think it was so nice. I've had it now for 14 years and haven't had it painted. Its starting to show wear and tear. Looks good from 10 feet away. I still have a few upgrades before I worry about paint. And even then I'm not sure if I'll have it painted. I enjoy driving it, and the last thing I want is to become paranoid about the paint. Don't get me wrong, I would like to have a nice paint job, but I'm not sure I'm ready to sacrifice the money and attendant **** TLC that invariably accompanies killer paint.
I'll post some dB readings next time I take it out.
Take care,
Mark
Team Owner
Joined: Jun 2001
Posts: 43,136
Likes: 155
From: Thomson Georgia
Re: Chassis dyno results (ML67)
That is one beautiful car and Equally powerful...........have u raced her at the track.........I would love to see that Chevelle and the GTX as well.....They had quite impressive numbers as well.............
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Re: Chassis dyno results (ML67)
ML67 that is one beautiful car and what a dyno run. Very impressive. What are the specs on your cam and what headers are you running. Great to have you on this side (c3) of the street.