And 4" to the roll-bar to allow for taller drivers - and 4" of width (well, you know...)

It seems to me that there is a lot of focus on the ability to accelerate and not on the ability to corner. The people saying the car is outdated and commonly available sports cars are faster aren't mentioning cornering. That same Z06 that is far faster than a spec racer down a straight is also far slower mid corner. I believe a showroom Z06 corners around 1g on stock tires and spec racers can sustain 1.25-1.3 g's in corners (haven't looked at date in a couple years, that's from memory).

Also, using a basic quarter mile ET calculator we can look at the effect of the extra power for the power hungry out there (assuming minimum weight doesn't change).

http://www.race-cars.net/calculators/et_calculator.html

If you input 100 whp and 1670 weight you get a 14.88 second quarter mile at 91.54 mph.
If you input 115 whp and 1670 weight you get a 14.21 second quarter mile at 95.91 mph.

That comes out to a 0.67 second/4.37 mph gain with 15 more horsepower. I know we aren't drag racing here but that would be a significant change in a competitive drag racers world. Straights at a lot of courses are 1/2 - 3/4 of a mile long. The same rate of mph increase doesn't continue but perhaps on a 3/4 mile straight we are talking about increasing top speed by 8-9 mph. That is a significant difference.

To put that in perspective easily let's look here:

http://www.csgnetwork.com/csgtsd.html

This shows that on a 4 mile track (let's use Road America as the example) if we average 90 mph it takes 2 minutes and 40 seconds to complete a lap. Let's say that with all this extra speed on the straights we average 5 mph faster around the track. That's worth 9 seconds at Road America. 9 seconds is a very large jump. Fast times now are 2:39's and 2:38's. Let's say the car is then capable of 2:30's. That makes it faster or as fast around Road America as a Porsche GT3 on Slicks (link for citation http://forums.rennlist.com/rennforums/9 ... erica.html).

What more could everyone ask for? As fast around the track as a $100k sports car on a $2k set of tires, most competitive racing you can find anywhere, closest cars, great support at the track, and good fields in almost every region, and all that for $30k ready for action.

Sounds awesome to me.

breton wrote:And 4" to the roll-bar to allow for taller drivers - and 4" of width (well, you know...)

I second the extra tallman kit idea. Just got in trouble at my last weekend for not being sufficiently under the roll bar.

cir-reed wrote:It seems to me that there is a lot of focus on the ability to accelerate and not on the ability to corner. The people saying the car is outdated and commonly available sports cars are faster aren't mentioning cornering. That same Z06 that is far faster than a spec racer down a straight is also far slower mid corner. I believe a showroom Z06 corners around 1g on stock tires and spec racers can sustain 1.25-1.3 g's in corners (haven't looked at date in a couple years, that's from memory).

Problem is, eventually the Corvette will buy proper tires and disappear into the distance. Lets face it were barely faster than a Spec Miata or Formula Vee, neither of which is known for being particularly fast. I do the occasional Time Trial, and an everyday CSP Miata is more than a match for me in the SRF (they are a good bit faster than the more limited Spec Miata). And you'll only see half a dozen at a good autocross. But I guess I am the only one who is embarrassed to get beat by a secretaries (or executive assistants) car in my bespoke race car.

BFun wrote:Lets face it were barely faster than a Spec Miata or Formula Vee, neither of which is known for being particularly fast.

So, what I'm reading here is a vote for a 2 liter Duratec with about 150 hp?

Erik, throw me in that briar patch! :^)

The comments opposed to adding a lot more horsepower have, sensibly, noted the likely effect on the strength and durability of other components. But for me a more important consideration is safety. Our current cars provide all the RACING endorphins I need, fast enough, quick in the corners, close racing. Now, read the report on the Sprints crash at the kink (where I had the misfortune of getting caught up in a similar incident at last year's Runoffs but without any serious injury) and ask yourself if you REALLY want to challenge the enviable safety record we have in SRFs by adding much more horsepower/speed. Force varies with the square of velocity. The modest bump Enterprises is considering is more than enough for me.

If I'm not mistaken, the few Rebello engine-powered Sports Renaults running in NASA out west sport 120-HP engines with roughly similar weights, if we were to go with 50-pounds less than now. Study of the safety and chassis durability records of those cars might prove useful.

For me, the idea of choking down to 120 HP what would otherwise be a 150-170 HP engine is very appealing from a durability standpoint. I think that would be the limit for our chassis and suspensions.

Think we'd stay with the same tires though?

tburt wrote:The comments opposed to adding a lot more horsepower have, sensibly, noted the likely effect on the strength and durability of other components. But for me a more important consideration is safety. Our current cars provide all the RACING endorphins I need, fast enough, quick in the corners, close racing. Now, read the report on the Sprints crash at the kink (where I had the misfortune of getting caught up in a similar incident at last year's Runoffs but without any serious injury) and ask yourself if you REALLY want to challenge the enviable safety record we have in SRFs by adding much more horsepower/speed. Force varies with the square of velocity. The modest bump Enterprises is considering is more than enough for me.

The safety is really important (and maybe essential) to me. I don't get the thrill in going down straights faster. That's just money, noise and fuel. I'd rather have a little aero and downforce than more HP.

Discussion about >120HP is pointless, as the ensuing need to reinforce other parts of the car will make the conversion cost prohibitive.
And if you want a spec sports racer that has more power and speed, Enterprises already sells them: the ESR - 170HP, 1250#. For Enterprises to make a converted SRF closer to the ESR performance would hurt the ESR, a car that needs buyers and racers to reach critical mass. And Erik's suggestion to buy a used FE and a body kit, for maybe $40K, is right on - that is around the price of a new, assembled, painted new SRF today.

Bob Devol wrote:For me, the idea of choking down to 120 HP what would otherwise be a 150-170 HP engine is very appealing from a durability standpoint.

"Choking down" a more powerful engine seems incompatible with it revving higher (per Erik's post above). Therefore, I presume Enterprises is looking at a new 1.5L (Fit?) or 1.6L (lots of choices), not a larger displacement engine. Less displacement revved higher means a bit more hoss-pressure at the big end, but less weight and torque to wear out parts at the low end. BTW, the Fit engine is tiny and light weight (about the size of a Kent), yet produces 135 hp without its inlet restrictor (capped at about 112 for FF).

IMO, the real challenge to SRF (and FE/ESR) is to reignite some growth. Sure, those who are satisfied to tool around 10 seconds slower than a Spec Miata probably see no reason to change, but how many new SRFs have been sold in the past 5 years? Are you going to see new cars and new blood enter the class, or will Erik continue to oversee a slowly shrinking world?

I hope you embrace growth.