Robin (UK) Posted April 29, 2017 Report Posted April 29, 2017 (edited) Steve and I ran our Plymouths at The Vintage Nationals at Santa Pod (UK) today. It was great fun. Steve's coupe ran very strongly and took the honors with a best ET of 20.6 secs at 65 mph. My convertible ran 20.82 at 64.61mph. I'm pleased with that... until the next time! If you're on facebook here's a video of one of our heads up races...https://www.facebook.com/christopher.reynolds.5203/videos/10154763507078795/ If the video link doesn't work for you, here's a still... Edited May 1, 2017 by Robin (UK) 9 Quote
knuckleharley Posted April 29, 2017 Report Posted April 29, 2017 Something is wrong with your link. Quote
Robin (UK) Posted April 29, 2017 Author Report Posted April 29, 2017 It must be something to do with account settings. The video's not mine but I'm trying to get it. Quote
55 Fargo Posted April 29, 2017 Report Posted April 29, 2017 Love it, very cool, not neck snappin but still cool. You folks in England enjoy the vintage racing scene, I am gathering.... 2 Quote
60steve Posted May 1, 2017 Report Posted May 1, 2017 Here's a good shot of Robin and myself I ran best of 20.6 @ 65 mph, hows that for a P15 coupe 6 Quote
Robin (UK) Posted May 1, 2017 Author Report Posted May 1, 2017 And some more pictures. All courtesy of Neal Read at Retrophoto... 3 Quote
55 Fargo Posted May 1, 2017 Report Posted May 1, 2017 Robin take off the mufflers for the race...LOL On my engine with straight pipes it will spin up much higher and launch like crazy... 1 Quote
T120 Posted May 1, 2017 Report Posted May 1, 2017 1 hour ago, 55 Fargo Spitfire said: Robin take off the mufflers for the race...LOL On my engine with straight pipes it will spin up much higher and launch like crazy... Or - exhaust cutouts. 1 Quote
55 Fargo Posted May 1, 2017 Report Posted May 1, 2017 10 minutes ago, T120 said: Or - exhaust cutouts. Sure that would work, used a lot on headers. I was quite surprised the RPM spin up difference with no mufflers, did not expect this... Quote
Don Coatney Posted May 1, 2017 Report Posted May 1, 2017 Just curious how one measures the RPM spin up difference? I don't know how to do this. Makes more noise with no mufflers so it would be a lot louder but there must be some way to measure the difference? I know race cars run open exhaust and many shave weight from the rotating mass but those results are measured in lower lap speeds. I run glass packs on my souped up Desoto engine and it sounds great but I really cannot make a statement that it spins up faster as I have no means to measure spin up speed. Quote
rb1949 Posted May 1, 2017 Report Posted May 1, 2017 Looks like rain doesn't cause any traction problems. Quote
Robin (UK) Posted May 1, 2017 Author Report Posted May 1, 2017 2 hours ago, rb1949 said: Looks like rain doesn't cause any traction problems. That's not rain... it's rubber on the track. 1 Quote
knuckleharley Posted May 1, 2017 Report Posted May 1, 2017 (edited) 3 hours ago, Don Coatney said: Just curious how one measures the RPM spin up difference? Maybe by using a tach and comparing ET's? Also,a 10 hp increase will be more noticeable in a 100 hp engine than a 400 hp engine,where it wouldn't even be noticed. Edited May 1, 2017 by knuckleharley 1 Quote
55 Fargo Posted May 2, 2017 Report Posted May 2, 2017 5 hours ago, knuckleharley said: Maybe by using a tach and comparing ET's? Also,a 10 hp increase will be more noticeable in a 100 hp engine than a 400 hp engine,where it wouldn't even be noticed. Well nothing scientific to this, just a plain seat of the pants feeling of spinning way up in the RPM band, and able to drive faster speeds in lower gears before shifting. You just gotta have an ear for this sorta thing I suppose. It was a night and day difference... Quote
55 Fargo Posted May 2, 2017 Report Posted May 2, 2017 (edited) Okay, this morning pulled off 1 of the 2 Thrush Turbo Mufflers, and immediately ,y engine would spin up to a much higher RPM and faster. I have a 4 spd truck trans, do not use the 6.08 to 1 first gear so 2nd-4th. In 2nd gear to 35 mph about 4000 rpm on my tach, and in 3rd gear up to 60 mph on the hghway at 4000 rpm, before shifting to 4th. This is a way higher than with both mufflers on. So tis does not take any special documentation to clearly see a difference....LOL And I am not sure why a muffler would do this, a side note, in 4th on the highway not so much difference, its lower speed in lower gears.... A pic in 3rd gear before shifting to 4th. 4000 rpm and approaching 60 mph, my speedo reads 11 mph lower so 60 is about 49 on my speedo. My apologies to Robin, as this is veering off his thread topic, so will move my topic back to the Chrysler flathead performance thread... Edited May 2, 2017 by 55 Fargo Spitfire Quote
knuckleharley Posted May 2, 2017 Report Posted May 2, 2017 " a side note, in 4th on the highway not so much difference, its lower speed in lower gears.... " That's because high gear lacks the torque multiplication of the lower gears. It's direct drive. What you experienced is true in all cars and trucks,regardless of how much power they have. It takes torque to "pull" higher gearing. Quote
Brent B3B Posted May 2, 2017 Report Posted May 2, 2017 On 4/29/2017 at 1:25 PM, Robin (UK) said: Steve and I ran our Plymouths at The Vintage Nationals at Santa Pod (UK) today. It was great fun. Steve's coupe ran very strongly and took the honors with a best ET of 20.6 secs at 65 mph. My convertible ran 20.82 at 64.61mph. I'm pleased with that... until the next time! very cool you two! I would blame it on being topless Robin, lets get you a racing top! I am pretty sure that wind resistance cost you the difference although, you might have gained some speed by all the shine on it 1 Quote
Robin (UK) Posted May 2, 2017 Author Report Posted May 2, 2017 1 hour ago, Brent B3B said: very cool you two! I would blame it on being topless Robin, lets get you a racing top! I am pretty sure that wind resistance cost you the difference although, you might have gained some speed by all the shine on it I tried top up and top down. Not much difference. I think the extra weight of the convertible was always going to be a handicap. My improvements through the day were, I believe, due to gaining experience of the start and the way the car was performing. It was my first time on a drag strip so I have a lot to learn! 1 Quote
55 Fargo Posted May 2, 2017 Report Posted May 2, 2017 21 hours ago, Don Coatney said: Just curious how one measures the RPM spin up difference? I don't know how to do this. Makes more noise with no mufflers so it would be a lot louder but there must be some way to measure the difference? I know race cars run open exhaust and many shave weight from the rotating mass but those results are measured in lower lap speeds. I run glass packs on my souped up Desoto engine and it sounds great but I really cannot make a statement that it spins up faster as I have no means to measure spin up speed. Did you miss something? My Fargo 228 engine, dual carter carbs, dual exhaust outlet, almost the same as yours. I have 2 inch pipe running to 2 mufflers, 1st ( were big Walker stock type), the new mufflers Thrush Turbos, installed same locations, exhaust dumps in front of the diff. So with no mufflers, my engine will easily spin to 4000-4500 rpm, in 2nd gear, I am reaching 30-25 mph before shifting to 3rd gear, 3rd gear, have taken it to almost 60 mph around 4000 rpm before shifting into 4th gear. With mufflers, at least these type, engine will rev easily to about 3000 rpm or so, in 2nd and 3rd gears, I have to shift way sooner at a lower rpm and speed to satisfy this engine. This verified by 3 things, my tach, my speedo and by GPS. Do you now understand the illustration? I am going to switch glasspacks tomorrow, and hopefully it will be a good compromise of power, exhaust flow and sound....... Quote
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