ntJeff

iTrader: (26)

Hey pals,

I'm looking to run mod buggy again. Been running stock for the past few months, but want to run mod again. gotta go fast.

I run on a small (less than 20 second lap) track, med-high bite clay.

I've been running a Trinity D3.5 Maxzilla 17.5. I'm geared 32/70.

I cranked the timing up to the max, and turned off blinky on my R10 Pro (stock boost/turbo settings)

It seems wicked fast enough (tires balloon like mad, they go full frisbee mode), but I'm afraid of heat.

Anyone do this, and have experiences with it?

henry

That's not unheard of to do. I run on plenty of smaller indoor tracks where the lap times between 17.5 and mod are negligible.

One thing. You WILL have to watch your heat. If I were you I would go back to no or little timing with the original gearing and incrementally test and bump those up until you have a good speed/heat compromise that you can drive effectively. You don't want to cook your motor. You don't want to add so much boost you break traction. You may even get better lap times with lesser boost due to control.

Spinouts and mistakes can punish a driver even more on smaller track than a larger one. So you definitely want to avoid that.

Mindcrimes

iTrader: (29)

i understand your question but why not just for over 40$ for a used mod motor like a 13.5

VenturaDC

iTrader: (32)

Or get a tacon 8.5t from hobbypartz for $35, geared 23\76 I find the low end very managable with ballistic top end.

vr6cj

iTrader: (124)

Well there is a good reason to run boosted 17.5 in mod class. You can lay the power down vs wheel spin to a certain point. Plus easier to drive more consistant.

ntJeff

iTrader: (26)

Because I don't have $40 to spare?

predu

iTrader: (6)

I ran a schuur speed 17.5 with 20 degrees timing amd 38 on can/ 40 is max geared 32/72 and it came off at 125ish and it was faat

1967rs

iTrader: (56)

I run on a mid size indoor track, stock guys are running 20 and 19, 13.5 is running 19 and 18, mod is running 18 and 17. You can run mod but I don't think you can win.

MarkA

iTrader: (21)

I ran a boosted 17.5 in mod buggy for a few weeks last winter when I was inbetween "real" mod motors. It was absolutely fine in terms of competitiveness, almost an advantage if the track got slick, expect for one area - if there was a big jump coming off a corner with short-run up, it wouldn't be much more than just a 17.5 in terms of clearing it whereas with an 8.5 you'd just squirt the throttle to about half and fly right over.

That being said, I'd +1 just buying a faster/real mod. You won't have to worry about temps ever (I can't remember the last time I even took my 8.5's reading, it was typically no more than 110 after a 8-10 minute practice run so I don't worry about it anymore) and since most mods will still be "too fast", you can buy used with greater confidence than you can 17.5's because the odds the mod motor was ever pushed/abused is much, much lower.

chevmaro

iTrader: (25)

Tires ballooning like mad isn't fast. You wont use that power. I like to run 13.5 boost in mod. Have ran 17.5 boosted also. 17.5 likes lower boost start RPM.

Derry

iTrader: (27)

You will want to gear down like 5 teeth on the pinion, turn up the boost. This gives you more low end and still plenty of top end while keeping the temps low. We used to run boost in the stock class at TRCR before blinky came along and this was the hot setup. I think I ran a 26 pinion

Dave H

As Henry and Derry mentioned if running 17.5 boosted back off on the endbell timing and gearing. Start with no more than the stock timing setting on the motor, and perhaps a 24~26 tooth pinion. The boost can more than make up for the endbell timing and gearing. Done right a boosted motor should run fairly cool, as it is always at fairly high efficiency.

Also agree with Mark, no amount of boost replaces the instant punch of a mod for a short jump run up. Depending on the track that may or may not be a limitation, as they can go pretty good otherwise.

Davidka

iTrader: (86)

Sounds like a great way to go and the other suggestions are all good ones. I'll add that where this configuration may struggle is if your track puts in a layout with a critical jump that has a short approach. A 17.5 motor can output only so many watts. This is where a lower turn modified motor might become necessary. You can get off brand stuff for less than a set of tires and wheels if the need arises.

asc6000

iTrader: (15)

You'll be at a slight disadvantage powerwise but the thrill of a good clean drive to a podium finish feels pretty good when you do pull it off. Don't do it too much or at some point you may loose a little ability to handle raw power that sometimes you simply must have in open/mod. Do it, I love it.

xTotalghost

iTrader: (4)

Buy a smc mod motor for 50$ and don't risk ur electronics