Ojala
Ojala GRM+ Memberand Dork
5/29/23 11:41 p.m.

Where are some current resources for f-mod? Apex speed is kinda slow and I most of the links mentioned in old "learn me" posts are dead. I am guessing that f500 cars are the best choice for price/maintenance but I'm having trouble finding car packages for sale. I would REALLY rather buy a car, trailer, and spares package instead of just a car but I guess i'll do what I can with what's available.
 

Conversely I know of a LOT of legends cars for sale but, if I understand this correctly, they aren't competitive with f500 cars. 

Apexcarver
Apexcarver UltimaDork
5/30/23 8:31 a.m.

https://www.facebook.com/groups/360619197459057/

 

Fmod/F500 Facebook group is kind of the nexus for everything 

Let me know if you have any questions, I've had mine since 2018.

David S. Wallens
David S. Wallens Editorial Director
5/30/23 9:03 a.m.

Paging JG, paging JG. 

Apexcarver
Apexcarver UltimaDork
5/30/23 9:54 a.m.

https://www.facebook.com/groups/360619197459057/permalink/2237149836472641/?sale_post_id=2237149836472641

Ok deal

 

https://www.facebook.com/groups/360619197459057/permalink/2212525932268365/?sale_post_id=2212525932268365

Good all in package with trailer

https://www.facebook.com/groups/360619197459057/permalink/2193519647502327/?sale_post_id=2193519647502327

Heck of a deal if you want to roadrace, but the 600 isnt likely the greatest for autox

 

That's at least whats active in the group right now, there may be more for sale sitting around.  If you post a "wanted" in there you wont get chased away. 

 

Seriously, if you want to video chat or something sometime for a runthrough and a look at mine (not for sale), we can work something out to answer any questions. 

 

Here's my "build" thread https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/so-i-went-and-bought-a-racecar-f500/146445/page1/

I got my car off of Apexspeed. Again, the facebook group is the most active home for the classes right now. 

Tom1200
Tom1200 UberDork
5/30/23 10:51 a.m.

I've been running F-mod and F500 since 2014. 

The Facebook page is the place to go.

As for Legends cars they are indeed slower than F500/600 cars.

Trailers are non issue because any small trailer will haul the car. 

For autocross you don't need a large spares package; the bulk of the things you need are still available (gaskets, rings etc.) All you really need are some plugs, jets and maybe a spare belt. For national events you may want to bring more (things like clutch & motor parts).

F-mod / F600 are the cheapest as well as fastest non winged formula cars. 

 

JG Pasterjak
JG Pasterjak Production/Art Director
5/30/23 11:12 a.m.

+1 on the facebook group. There's good info in there and the folks are friendly to noobs. The cars are dead simple and as many spares come from Grainger as they do specialized race shops. So really all you need is the basics (extra belt, some jets, chain) and Mike Quadrini's phone number. 

Apexcarver
Apexcarver UltimaDork
5/30/23 11:36 a.m.

To back up what Tom said, I think you could roll into Lowes and buy an open trailer that will tow one of these for about $1500 brand new and they are light enough that you dont need much in the way of tow capacity, many smaller thana truck vehicles can tow these.  Car weight is only 650lbs without driver in my case.

Ojala
Ojala GRM+ Memberand Dork
5/30/23 1:17 p.m.

So for a good car with spares but without a trailer is $8500 a good budget? Alternatively is $10k a good budget for a car with spares and a trailer? That would be a car for which I can pour a seat and be good to go?

After that is $1k/year a good budget for continuing consumables and maintenance budget? The cars look extremely simple to work on and I have made more than a few trailers but we all know how its always cheaper and easier to buy someone else's finished car.

Apex, you said that the f600 you listed above is better suited to road racing. Is that a function of the transmission, engine, rear gearing, or something else?

Tom1200
Tom1200 UberDork
5/30/23 1:52 p.m.
Ojala said:

So for a good car with spares but without a trailer is $8500 a good budget? Alternatively is $10k a good budget for a car with spares and a trailer? That would be a car for which I can pour a seat and be good to go?

After that is $1k/year a good budget for continuing consumables and maintenance budget? The cars look extremely simple to work on and I have made more than a few trailers but we all know how its always cheaper and easier to buy someone else's finished car.

Apex, you said that the f600 you listed above is better suited to road racing. Is that a function of the transmission, engine, rear gearing, or something else?

Autocross cars tend to be cheaper than road race cars; SCCA changed the roll bar specifications and some of the older cars are no longer eligible. Car prices vary wildly anything from 4K to 12K.  For instance my car, 1987 Novakar, cost me 2K (plus $1300 to ship it cross country) because it's an older non  SCCA road race legal car. I actually vintage race it along with doing autocross.  I've now spent 6K total; upgrading the motor from the obsolete AMW to Rotax 494 and replacing the fuel cell plus some other small things.  Basically you have to wait and see what comes along.

For a regional car 1K is likely a good number. For the first 7 years I owned my car all I did was autocross it. I estimated my fully amortized costs (including entry, tires & fuel) were $150 per event for about 8 events per year. I'd run the tires for 18 months.

The class is now officially F600. Most competitors are using either a 583cc Rotax or 600cc bike motor. The bike motored cars are better suited to road racing. The CVT transmission and two stroke motor are better suited to autocross.

If you are only running locally the motor isn't that critical. Since you wish to run F-Mod I would look for a two stroke car; they are cheaper and as mentioned better suited for autocross.

Here is a run in from when my car still had the AMW (2-stroke) motor in the car.

https://www.youtube.com/watch?v=4IWZgHRDsg0&t=83s

 

Ojala
Ojala GRM+ Memberand Dork
5/30/23 3:34 p.m.

In reply to Tom1200 :

Well thats quite a bit cheaper than I thought. Right now I will stick to autocross, but I retire in December 2026 and will be able to travel extensively. But for that kind of money I could just pass the autocross car along and get a roadrace car  without really losing any money.  It makes sense to put out feelers and wait till the right car becomes available. 

 

Tom1200
Tom1200 UberDork
5/30/23 4:09 p.m.

In reply to Ojala :

Given an autocross car runs all of 10 minutes a day; it would take several seasons wear out the rings on a two stroke.

The key is to not go crazy on the jetting looking for that last 1-2hp. 

Apexcarver
Apexcarver UltimaDork
5/30/23 4:38 p.m.

What I would say is if you're shopping for just an autocross car. Hold tight for the end of the season and you can probably pick up a good sorted autocross only car for somewhere between $2,500 and $6,000. Cars that can go roadracing tend to cost more. A thing to consider is a road race car has to have an FIA fuel cell as well as a fire system and several other things. For reference, the fuel cell in my car cost over $1,000, you don't need a fuel cell and can just use about any tank in an autocross car. And as Tom said the cheap autocross only cars would basically involve cutting the car in half to upgrade the roll hoop to be able to go road racing again.

That said, if you want to go road racing eventually going ahead and getting that 600 that's ready to run is a very good deal. But you would be giving up fair amount in autocross performance using the motorcycle engine and having to shift versus the CVT on the snowmobile. 10 grand is a very very good price for a road race legal 600 bike motor. They tend to command more money and I wouldn't be surprised if it had been listed for five grand more than what it's listed for.

Snowmobile engine versus CVT is a very big drama within the class. Their performance balanced so the big snowmobil engines the 583s are competitive with the 600s. That being said, the older snowmobile engines the 494s and so on. Well not really competitive for road racing can still run and do okay but you won't be regionally relevant. They'll be a midpacker. The reason The motorcycle engine is better for road racing has a lot to do with not having to deal with carb setup and clutching of the CVT. I haven't had any major headaches with my CVT for autocross only and several years and I think most of it boils down to getting the last 10th out of it is difficult for road racing or even for autocross but I haven't gotten my head down on the last bit of performance.

Tom1200
Tom1200 UberDork
5/30/23 5:09 p.m.
Apexcarver said:

Snowmobile engine versus CVT is a very big drama within the class. Their performance balanced so the big snowmobil engines the 583s are competitive with the 600s. That being said, the older snowmobile engines the 494s and so on. Well not really competitive for road racing can still run and do okay but you won't be regionally relevant. They'll be a midpacker. The reason The motorcycle engine is better for road racing has a lot to do with not having to deal with carb setup and clutching of the CVT. I haven't had any major headaches with my CVT for autocross only and several years and I think most of it boils down to getting the last 10th out of it is difficult for road racing or even for autocross but I haven't gotten my head down on the last bit of performance.

To expand on this: 

When I started running F500 one of the now defunct forums had a clutch tuning guide. It had a baseline set up (something like blue spring on the second preload hole) and my car was actually set up this way.  The statement was the baseline set up that would work 95% of the time.................I simply went with that and called it good. I'm well aware I'm giving up some time but I'm also aware I'm not a master of clutch tuning. My thought was and is best to get it right 95% of the time rather than shooting myself in the foot.

The only clutch work I've done to date is simply maintaining it; as the belt wears I adjust the side clearance.

As for the rest of the car I do the same; I simply maintain it. The car has been no more fussy to run than my Datsun.

Apexcarver
Apexcarver UltimaDork
5/30/23 5:50 p.m.

Exactly, the motorcycle engine is great because it's close to optimal without fine tuning. The 2 stroke is great to 95%, but all the effort chasing the last bit of performance. Not all the effort to get/keep running.

 

As far as autox, I remove my carbs and drop the float bowls at the start of every season and spray out the jets and run a brush/appropriately sized drill bit through them. It's a carb that has been sitting thing really. I wind up doing similar in most of my lawn equipment too. It hasn't been a bad autocross car. You also just get a routine to nut and bolt the car between events. Vibration is real.

 

I get to an event, roll it out of the trailer, jack up the rear and start it (choke 1 carb for 1st cold start) and run it till it's up to temp.( As an aside, the two-stroke needs to run colder than you are used to. I look for water temp of 120 as optimal. Above 135-140 is flirting with trouble.) From there it should be good to start on the ground for the rest of the day, provided it's not a very cold day.  I carry a shore battery to grid that I plug into between runs that operates a supplemental electric water pump and the fans while the engine is off. Tire pressures are about 13-14psi. Aside from those particulars, it's not difficult or intensive to keep going.

 

A side note, some of the older engines are harder to find parts for. If it's smaller than a 494/493 I would just say do your research and know what you are walking into. Tom knows way more than I do on this issue. I have a 494 and if I start roadracing I'd be starting to look for a 593 engine upgrade to be competitive. Most new autox builds are using 593 as well, even though they have a higher minimum weight. (See rule book) 

Ojala
Ojala GRM+ Memberand Dork
5/30/23 6:29 p.m.

I appreciate all the detailed knowledge. Sounds like this fall after Nationals is a good time to buy. 

On a side note my wife is very pleased how cheap this racing class is

Apexcarver
Apexcarver UltimaDork
5/30/23 6:53 p.m.

Set of tires is I think still under $1000, with how wide they are on this light of a car they last a long time. Performance dead before worn out usually. 

One gotcha is if you have a car with an FIA cell (ie a roadrace legal car) the fuel cells are incompatible with ethanol. Meaning you need to find ethanol free.  They run fine on pump gas otherwise though. I run race gas as it's the easiest ethanol free for me to find. The fuel cells last about 10 years and as previously mentioned, are expensive (and not needed for autox). 

Tom1200
Tom1200 UberDork
5/30/23 7:19 p.m.
Apexcarver said:

A side note, some of the older engines are harder to find parts for. If it's smaller than a 494/493 I would just say do your research and know what you are walking into. Tom knows way more than I do on this issue. 

Prior to converting to the 494; I was one of the few people running the AMW brand motor. I manged to find rings and some gaskets (Suzuki RM250 head gaskets worked). I made some gaskets myself.  The AMW motor would still be running f I only autocrossed it.  I put 8 hours on the motor road racing it; that would have been another 6 seasons of autocross.

I would not shy away from a AMW powered car; the conversion to the Rotax motor was a simple case of making a new engine plate and rerouting the coolant lines. You could run the AMW till it blew up and then convert the car.......which is what I did.

I too went to the  Rotax 494; I managed to buy up another racers stash of 4 Rotax 494 engines and spares when he went to the Rotax 583.  I bought everthing for $1500.

Note I also run 100 octane race gas.

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