We've all read about the 17.5 with LiPo's and the near spot on comparison with the 10.5 on 4 cells. That's all good for the 10.5 guys hoping to switch to LiPo's someday.

But, the 13.5 on 4 cells is not very far off the 10.5 with 4 cells. As a matter of fact I've seen some 13.5 cars that were faster than some 10.5 cars. I know that it was most likely because of setup and/or driver, but the point is there is not much separating the classes except a couple aerodynamic rules and the motor.

I would like to know how the 17.5 performs on 4 cells.

Surely it is slower. But I would like to hear about some on track performance comparisons to the 13.5/4cell setup.

Any other thoughts are welcomed also!

Could a 17.5/4 cell class be a new and improved spec class?
I've raced spec before - spec motor, battery, tires. And IMO there was nothing "level" about that playing field. I've heard how the cells for spec battery packs are chosen. And as in any brushed motor class, you'll find good ones and not so good ones. The tires are probably the only level part of the spec racing playing field.
I also realize that brushed spec racing is a good, inexpensive place for a newbie to start. It should not be brushed under the carpet. No pun intended. But, I know we have a lot of guys that love brushless racing and would like to run a bit slower than 13.5/4 cell.

OvalTrucker,

I only had one opportunity to try the 17.5 on 4 cell in a 'sportsman stock' class on a short flat asphalt track.

One run with a calculated gear ratio it was running the same lap times as the race TQ...I was pretty confident I'd be able to improve on that on the second run (which would have been the main) but I screwed up...and didn't read the posted MAIN SHEETS and the track ran the "A" MAIN for Sportsman Stock before the "B" Main for 10.5 (which I was running with the same car) Needless to say, I had the WRONG motor in the car...at the wrong time.

Since the 17.5 motor is available, I'm hoping to see SOMEONE give this a try SOON - maybe even some of our guys...but we'll be testing the new 21.5's on LIPO over the next few weeks as well. (which hopefully will have similar results)

(I think we've got 4 or 5 guys ready to try the 17.5/4 cell for the rest of the season...we'll see at the next event)

Thank you swtour.

When you say you hope to have similar results with the 21.5/LiPo - do you mean similar to 17.5/4 cell? That would be great. It could get the LiPo bandwagon started in pancars up here in Michigan.

Last night we had our first 4 cell 17.5 race. Our track, Lail Speedway (http://lailspeedway/rc50.com), is a concrete banked oval. 242' run line with around 16 degree banking. We run five minute races.

First of race times start at 4.7 to 4.8 and drop off to 4.9 to 5.0. This is very close to what we ran with stock 27t motors. On our track you can gear the heck out of the 17.5. I was running 90/57 and some ran a little more than me 88/57 or there abouts. After about the first 14 to 16 laps motor's seemed to drop to the 4.9's and then stayed consistant the rest of the race.
Motor was coming off the track at around 160 degrees in the heat of the day and my motor came off the track in the main at 140 degrees. As of this weekend the 17.5 is about .50 slower that our 13.5 class.

I believe that this motor will have a good following at our track.

Ovaltrucker,

Yes, the 21.5 w/ LIPO should run really close to what the 17.5 on 4 cell will...or at least that is where the target is...

Ovaltrucker,

Yes, the 21.5 w/ LIPO should run really close to what the 17.5 on 4 cell will...or at least that is where the target is...

Some of the Busch (Spec) guys here in Indy have been talking about the 21.5 and a Lipo pack for this coming fall's carpet season. Of course at the Velo we want to keep the speeds up, but should take the tinkering out of the Spec motors. Would love to see Enduro racing come back... some of us Velcro our packs, instead of battery tape... which works well for enduro racing.

Just waiting to see one of the 21.5... any others on the horizon??

See ya at the Track...
Greg

17.5 4 cell is as close to 4cell 27t as you can possibly expect for it to be. I hope that folks will look at this motor as a slower class for the BRL and not make a second 13.5 class! I also run at Lail's and it was very tight racing at a very controlable speed just like 27t stock.

It took Novak 3 attemps to slow a motor down to stock speed but they got it this time!

Bryan Blaser got to run 4cell w/ 17.5 a little at HotRod Hobbies over the weekend...found it quite competitive right away.

His comments were it was a tad slower up front - but faster on the tail end of the run (must be the effieciency of the B/L ya think?) But pretty equal in the overall run.

He also ran his 17.5/LIPO for the first time w/ the 10.5/4 cell guys. He was about a 1/10th off per lap in this first attempt, but he was so tickled to run ALL DAY LONG on a single battery....and he said "This LIPO Deal is going to cost MORE MONEY for TIRES"

Why? "Because you are going to be able to get SO MUCH MORE TRACK TIME Practicing - YOU'LL BURN THEM UP"

Joe, what is rollout for 10.5 4cell @ HotRod Hobbies? I bet Bryan was under geared. 5-6 teeth higher than 4-cell/10.5 gearing.

Raymond

I told him the same thing when I spoke to him on the phone Monday.

He was only like .15 different in the rollout or something...I told him he should probably have been close to a .3 to a .4 difference. (2.9 vs 3.3 maybe)

Yeah Joe, I can't wait for RCSM to open back up in September so we can get some good clean testing with 17.5/lipo. We think it is very close where we are running now but myself and Jeff both think it's going to be faster than 10.5/4-cell time it's all said and done. Joe shoot me a e-mail with your addy and I will get the test motor Jeff has back to you.
Any news on the 21.5 yet? testing?

Raymond

Yesterday, we officially released the SS Pro 17.5T motor information to all Novak Distributors. The motors have been available for a while, but in limited release.

The specs are pretty much the same as the other SS Pros, but the unloaded Kv is 2200 RPM/volt. We hope to have the information and the updated BL motor spec chart posted to the TeamNovak site by next week.

The motor inductance information for the 17.5T was also added to our motor compliance page (scroll to bottom):

How to Check for BL Motor Compliance (http://www.teamnovak.com/Tech_info/motor_tech/index.html)

For those who are interested i ran a 17.5 for the first time last night. It was a flat carpet track, very tight turns. The 17.5 was at worst equal to a very very good stock motor. I would guess that if I had a little more experience at that track, if it wasn't my first time on carpet since March and if they were a few more guys to bring the bite up it would have broken the stock track record.

basically, it was not unreasonable to run the two together but I'd say the 17.5 will turn out to be a little faster. I don't think that is a bad thing though.

Pat, That was with a 4 cell correct?

Yes...

That up at Maximus, Pat? Back here, we've been wondering how a 17.5 would really match up to a stock motor...

That up at Maximus, Pat? Back here, we've been wondering how a 17.5 would really match up to a stock motor...

No, that was at Radical Rick's.

I think they will match up decently, but 17.5 will have the edge. Some have said the 17.5 is slower, but my guess is they were under geared. I geared about 60 points higher then I would have with 13.5.

Thanks for the info, Pat!