1LikesU.S. Vintage Trans-Am Racing
01-15-2008, 08:05 AM
#137
I'm a bit confused regarding the 17.5 FDR.
I currently run an S400 with a 96s and 41p. It's blazin' fast in TC 13.5/6 cell. With your spreadsheet, I can go up to a 53p using the same spur before I break the 4.0 FDR. I have a 17.5 on the way. Even with a 17.5/4 cell package, I can't see how this setup isn't going to be very fast.
Is the FDR max 4.0, or is 4.0 the minimum? Either way, I've never geared that tall. Am I missing something?
Allan
I currently run an S400 with a 96s and 41p. It's blazin' fast in TC 13.5/6 cell. With your spreadsheet, I can go up to a 53p using the same spur before I break the 4.0 FDR. I have a 17.5 on the way. Even with a 17.5/4 cell package, I can't see how this setup isn't going to be very fast.
Is the FDR max 4.0, or is 4.0 the minimum? Either way, I've never geared that tall. Am I missing something?
Allan
With your car on 4-cells and a 17.5 brushless motor, you will need to pinion up to a 52T with the same 96T spur to get a final drive ratio of 4.025, which is as close as you can get without going to a smaller spur in the car (which would probably be a good move for the 17.5).
Those motors actually did get faster below 3.999, but we wanted to try to keep everything as balanced as we could while there are still brushed motors being used in this class. If the class progresses like I think it will, the likeliness of the brushless FDR mandate vanishing is realistic.
doug
01-15-2008, 03:08 PM
#140
There are a few different ways people speak of gearing and final drive ratios, but in this instance, you cannot "gear up" above 4, confusingly meaning that you cannot have a final drive ratio of 3.999 or below numerically.
With your car on 4-cells and a 17.5 brushless motor, you will need to pinion up to a 52T with the same 96T spur to get a final drive ratio of 4.025, which is as close as you can get without going to a smaller spur in the car (which would probably be a good move for the 17.5).
Those motors actually did get faster below 3.999, but we wanted to try to keep everything as balanced as we could while there are still brushed motors being used in this class. If the class progresses like I think it will, the likeliness of the brushless FDR mandate vanishing is realistic.
doug
With your car on 4-cells and a 17.5 brushless motor, you will need to pinion up to a 52T with the same 96T spur to get a final drive ratio of 4.025, which is as close as you can get without going to a smaller spur in the car (which would probably be a good move for the 17.5).
Those motors actually did get faster below 3.999, but we wanted to try to keep everything as balanced as we could while there are still brushed motors being used in this class. If the class progresses like I think it will, the likeliness of the brushless FDR mandate vanishing is realistic.
doug
I don't mean to over-elaborate on this, but I need a little more clarification.
In our racing circles, 'gear up' means add teeth to your pinion. Thus, giving a faster top end speed.
What I am hearing you say is: The FDR "number" cannot be below 4.0. In the S400, thats an 88s and 47p (4.082). That's the gear ratio that Andrew Mowery ran at Novak this year in his Serpents! Even with dropping 2 cells, its gonna be fast.
I'm going to test the chassis this weekend at "The New Year's Rumble" @ LSRCC. Track size is 100'x48'. Next week I'll also test the same setup on the carpet at The RC Barn, 36'x58'. That's where the T/A class is getting started.
Please confirm that I am finally understanding your formulas and the rules.
Thanks
Allan
01-15-2008, 03:30 PM
#142
In our racing circles, 'gear up' means add teeth to your pinion. Thus, giving a faster top end speed.
What I am hearing you say is: The FDR "number" cannot be below 4.0. In the S400, thats an 88s and 47p (4.082). That's the gear ratio that Andrew Mowery ran at Novak this year in his Serpents! Even with dropping 2 cells, its gonna be fast.
Please confirm that I am finally understanding your formulas and the rules.
What I am hearing you say is: The FDR "number" cannot be below 4.0. In the S400, thats an 88s and 47p (4.082). That's the gear ratio that Andrew Mowery ran at Novak this year in his Serpents! Even with dropping 2 cells, its gonna be fast.
Please confirm that I am finally understanding your formulas and the rules.
Yes, any FDR 3.999 or numerically lower is not allowed. The cars geared this way with a 17.5 is identical in speed to a 27T on 4-cells. It's not too slow, and not overly fast. It's a very good speed for a car with little or no aero and hard compound treaded rubber tires.
Try it out and let us all know how it works out for you.
doug
01-15-2008, 04:25 PM
#144
So Doug, when do the royalty checks from HPI start rolling into you and the Trackside guys for selling all these tires and bodies to people?
And I see you're in North Aurora, now? If you're looking for someplace local to show off the class, have you thought about the Hobbytown St. Charles parking lot races? Perfect sized track, and efinitly a causual crowd that just might love this type of scale looking class. And I've had several specators come up and ask me questions in the times I've made it out there.
And I see you're in North Aurora, now? If you're looking for someplace local to show off the class, have you thought about the Hobbytown St. Charles parking lot races? Perfect sized track, and efinitly a causual crowd that just might love this type of scale looking class. And I've had several specators come up and ask me questions in the times I've made it out there.
... as long as they bring out more vintage bodies, I'll be happy.
01-15-2008, 06:38 PM
#147
I figured out the stickers.
According to research:
The lighter headlights are for the 68 Z28, which did not have headlight covers, and had well displayed front running lights. The darker color lights seem to simulate headlights behind the mesh covers/grill of the RS and SS models. I have a second HPI 68 Camaro body, and it only includes the Z28 style lights. Just in case anyone cared...haha.
According to research:
The lighter headlights are for the 68 Z28, which did not have headlight covers, and had well displayed front running lights. The darker color lights seem to simulate headlights behind the mesh covers/grill of the RS and SS models. I have a second HPI 68 Camaro body, and it only includes the Z28 style lights. Just in case anyone cared...haha.
01-16-2008, 07:49 AM
#149
A lot of people have asked me about resources for reference material on vintage Trans Am cars and paint jobs. I figured I'd throw some of what I have used for references for those of you looking for period-correct paint styles...
Pat Smith Racing Photos
Frank Sheffield Historic Trans Am Photos
Historic Trans Am
AMX Javelin Trans Am
Trans Am Slot Cars
Trans Am Mustangs
Dodge Challenger T/A
Swede Savage Tribute Page
Dan Gurney AAR Cudas Photo Gallery
Pat Smith Racing Photos
Frank Sheffield Historic Trans Am Photos
Historic Trans Am
AMX Javelin Trans Am
Trans Am Slot Cars
Trans Am Mustangs
Dodge Challenger T/A
Swede Savage Tribute Page
Dan Gurney AAR Cudas Photo Gallery
01-16-2008, 09:21 AM
#150
For all those who bi@#$, complained, or whatever about 17.5s being run here. Please note that ROAR just approved the 17.5 BL motor to run with 27T Brushed motors.
So if anything the USVTA just approved it first :P LOL
Trans Am Mustang site...sweet!!
SS...RS...blah...we are talking BOSS302s!!
So if anything the USVTA just approved it first :P LOL
Trans Am Mustang site...sweet!!
SS...RS...blah...we are talking BOSS302s!!