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Re: SRF3 operational costs

PostPosted: Tue Aug 29, 2017 1:32 pm
by Bob Devol
You'll need to note that all engine rebuilds are only through SCCA Enterprises, all transmission rebuilds are only by SCCA Enterprises franchised CSRs (or certified re-builders) all shock work is SCCA Enterprises or certified re-builder. For details on certified re-builders contact SCCA Enterprises.

Re: SRF3 operational costs

PostPosted: Thu Aug 31, 2017 1:51 pm
by pmiranda
I think you can get more than 8 heat cycles out of the tires. I'd say 12, although I'm not great at keeping track of it.

Re: SRF3 operational costs

PostPosted: Thu Aug 31, 2017 2:58 pm
by Bob Devol
I think 12 (or even more) might be closer. I've heard of guys winning Majors on more than 12.

Also should be noted that there is no first heat cycle advantage with these tires. Probably more like a first cycle disadvantage. And there are Regionals (maybe a few Majors, too?) being won on tires that are darn near down to the cord at 15 cycles-plus.

What's more, it's really, really hard to fry a set of the rains in the dry.

Re: SRF3 operational costs

PostPosted: Thu Aug 31, 2017 8:04 pm
by Greg Holmberg
Greg Holmberg wrote:As someone who doesn't own or race an SRF3, the two things that surprised me most in the above data (given by SRF3 racers over on apexspeed.com), is the long engine life and the short gearbox life.

To be clear, in this survey, I'm not asking for the cost of the average mid-pack car in a regional race. In order to make an apples-to-apples comparison across so many classes, the scenario is a car that's capable of winning a Major or finishing in the top five at the Run-offs. In some classes, such as Formula Enterprises or (I think?) SRF3, nearly all cars meet this criteria, so I have to make that the scenario for comparison.

Can anyone confirm the engine life and gearbox life:

Engine rebuild, $: 5,000
Engine competitive hours: 200

Gearbox rebuild, $: 3,500
Gearbox hours: 100


No one commented on the 200-hour engine life. This is twice as long as any other engine in the spreadsheet. Are you sure about this?

Here's the scenario. You have a fresh engine producing power that is competitive in a Majors race or the Run-offs. It produces this power for some amount of time, and then starts to fall off, and at some point is no longer competitive. You send the engine back to the builder, who does whatever is necessary for that particular engine (some classes more, some less) to make it competitive again. How much does the builder charge for this? And how many hours did the engine operate competitively before becoming non-competitive?

Re: SRF3 operational costs

PostPosted: Thu Aug 31, 2017 8:42 pm
by Neil63
The engine life at 200 hours may be conservative. This engine is stout. Currently the transmission is the weak point in the package. Mike will probably have that rectified soon. Tires are track and driver dependent but 12 cycles is a reasonable estimate

Re: SRF3 operational costs

PostPosted: Thu Aug 31, 2017 10:39 pm
by Jparris
I think part of the reason why you're not getting any input on engine life is because it's so new. I'm not sure how many owner/drivers have had a GEN3 rebuilt yet (for reasons other than a major engine failure). I did my own GEN3 conversion in the winter between the 2015 and 2016 racing season, running my first event at the Blackhawk Farms Majors in April, 2016. I just last month converted over to synthetic motor oil, which is recommended after 30 hours of engine operation. My GEN2 engine had 5 years on it when I bought it, I put 6 more years on it, and it was still running strong when I pulled it to replace it with the newer GEN3. The new engine seems to have promise in being at least as durable as the GEN2, if not more. But how many hours? Who knows? I suggest there's not yet enough field data to make a statistically significant conclusion.

As for tire heat cycles, I'm getting about 16 out of mine, but I'm not exactly a Majors podium driver. As many have stated already, the gearbox and clutch are the Achilles Heel of the GEN3. The new clutch with springs and straight cut gears are rumored to help extend transmsssion life, but I doubt if there is yet empirical data sufficient to document how much.

Re: SRF3 operational costs

PostPosted: Fri Sep 01, 2017 9:14 am
by peterjank
Greg Holmberg wrote:
Greg Holmberg wrote:No one commented on the 200-hour engine life. This is twice as long as any other engine in the spreadsheet. Are you sure about this?

Here's the scenario. You have a fresh engine producing power that is competitive in a Majors race or the Run-offs. It produces this power for some amount of time, and then starts to fall off, and at some point is no longer competitive. You send the engine back to the builder, who does whatever is necessary for that particular engine (some classes more, some less) to make it competitive again. How much does the builder charge for this? And how many hours did the engine operate competitively before becoming non-competitive?


I think the 200 hour figure is reasonable as long as you do not mechanically over rev the engine on down shifts. Last Spring, I had three engines run on a dyno. One of the engines had 150+ hours of on-track run time and its chart was essentially identical to a fresh engine with 5 hours of run time on it.

The GEN3 engine requires extensive break-in due to the tight tolerances in manufacturing. It actually makes noticeably more power after being run in for 5 hours than it does immediately after a rebuild.

The electronic rev limit of 6,700 helps extend engine life. The engine could definitely pull hard well above that.

Re: SRF3 operational costs

PostPosted: Mon Sep 11, 2017 11:56 pm
by Greg Holmberg
OK, it appears that all the discussions in all the communities have died out, so you can find the results in the spreadsheet.

Re: SRF3 operational costs

PostPosted: Thu Sep 14, 2017 5:47 pm
by Jparris
One suggestion: In the engine model column, a more specific designation for the SRF3 engines is a Ford Sigma engine, which is a part of the Duratec family.

Re: SRF3 operational costs

PostPosted: Thu Sep 14, 2017 9:12 pm
by Greg Holmberg
Jparris wrote:One suggestion: In the engine model column, a more specific designation for the SRF3 engines is a Ford Sigma engine, which is a part of the Duratec family.


OK, I'll change it to Sigma.

Reading the wikipedia pages on the Duratec and the Sigma, I thought it was the other way around--Sigma was a family and Duratec was more specific. It's confusing.