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Your overall favorite engine for a Lotus 7 variant.


Ruadhd2

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and continuing..... Just wondering, in the Ultralite community, if anyone has track day driven both the f20c and the f22c with compareable gearing, I have 3:90 LSD, and which one would be considered better for 4 to 5 track days a year for driveability. I have 4 good track days under my belt now at Oregon Raceway Park, amazing track, and my f20c kind of spooks me comming out of tight corners using 2nd and trying to keep it running between 6k and 8k, so I just motor along using 3rd and then 4th on the straight. I'm usually as fast or faster than the drivers in the intermediate class. With the torque lower in the rpm band,of the f22c, will the power come on smoother than warp 9 of the f20c when engaging the v-tech? I have a good lead on a complete f22c, or should I just buck up and learn to drive like the big boys? I never plan on racing, just track days.

thanks

mike

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and continuing..... Just wondering, in the Ultralite community, if anyone has track day driven both the f20c and the f22c with compareable gearing, I have 3:90 LSD, and which one would be considered better for 4 to 5 track days a year for driveability. I have 4 good track days under my belt now at Oregon Raceway Park, amazing track, and my f20c kind of spooks me comming out of tight corners using 2nd and trying to keep it running between 6k and 8k, so I just motor along using 3rd and then 4th on the straight. I'm usually as fast or faster than the drivers in the intermediate class. With the torque lower in the rpm band,of the f22c, will the power come on smoother than warp 9 of the f20c when engaging the v-tech? I have a good lead on a complete f22c, or should I just buck up and learn to drive like the big boys? I never plan on racing, just track days.

thanks

mike

 

Mike,

You might think about: There's been some discussion on rear ends in past threads, WestTexas seems to have this area pretty well down with respect to the Subaru diff you're running. If you compare ratios with a performance calculator that gives input HP:gear ratios -> acceleration, I think you'll find that a 4.11 diff may buy you a whole lot more than switching to an engine with a bit more torque, and still give you a very drivable package. Powderbrake runs a 4.57 or some such ratio on the street with his WCM/Ultralite and the S2000 came with a 4.10.

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M Worth, I have a 3.9 in my ultralite... it's great for cruising (think it's the stock ratio for an S2000). I don't track mine as often as I thought I would and am glad I chose this ratio. To me, it's perfect for the foothills I drive and the freeway speed roads to get there. I'm sure it compromises lap times if your a good driver (I'm not).

The main reason for it originally was that I plan on putting a supercharger or turbo and this is the strongest diff. Plus with the extra power I think the ratio will be more practical.

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Thanks guys, I too am happy with the 3.90 for dual use, track and cruising, and if I was to do more track I would go for the 4.11. I just wonder if the f22c is more tractable and easier to drive quickly when v-tech is engaged?

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We're kind of getting off topic but if all you want to do is smooth out the vtec than get one of these:

 

http://apexi-usa.com/shop/index.php/afc-neo-fuel-management.html

 

(This worked great for smoothing my vtec, but I had other issues...)

 

A little better (if you eventually modify)

 

http://www.vividracing.com/catalog/greddy-emanage-ultimate-unit-p-10466.html

 

Or, all the bells & whistles; Hondata or AEM

 

http://www.scienceofspeed.com/products/engine_performance_products/S2000/engine_tuning.asp

 

You'd end up with a better result than switching stock engines... you do have to find a dyno tuner though

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and continuing..... Just wondering, in the Ultralite community, if anyone has track day driven both the f20c and the f22c with compareable gearing, I have 3:90 LSD, and which one would be considered better for 4 to 5 track days a year for driveability. I have 4 good track days under my belt now at Oregon Raceway Park, amazing track, and my f20c kind of spooks me comming out of tight corners using 2nd and trying to keep it running between 6k and 8k, so I just motor along using 3rd and then 4th on the straight. I'm usually as fast or faster than the drivers in the intermediate class. With the torque lower in the rpm band,of the f22c, will the power come on smoother than warp 9 of the f20c when engaging the v-tech? I have a good lead on a complete f22c, or should I just buck up and learn to drive like the big boys? I never plan on racing, just track days.

thanks

mike

 

Is your aim to do have fun at the track or actually become a better driver? With just 4 track days I'd suggest you spend time getting comfortable with VTEC rather than swapping the engine. An ideal lap in an Ultralite is spent with 100% of the time above VTEC regardless of engine choice. That said the stock F20C has 3k rpm of VTEC (6-9k) compared to the 2.5k rpm of the F22 (6-8.5k) which can mean less shifting on the f20 to stay in the powerband. Depending on your ECU you could also lower your VTEC engagement point and add a few hundred extra revs to the powerband

 

My Ultralite has an F20C which I damaged and eventually rebuilt into an F22 with no other drivetrain changes. The primary place where I notice the extra torque is on the highway where passing is effortless. At the track I try to keep it in VTEC so there really isnt that much difference. I do notice that I have to sometimes shift up an extra gear due to the lower redline though going faster is probably also contributing to that.

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4:44 will give you more grunt out of the corners as far as making it smoother not likely. It would likely make things more amplified acceleration changes dramatically between 3:90 and 4:44. What it might change is which gear you are in going thru the corner. Instead of second at 6k you will be In third at 5200. I prefer the 4:44 it will run about 3300rpm at 70 compared to 2853 at 70 with the 3:90. That's assuming 26" tall tire. Apexi tuner will allow you to tweak the vtec engagement point and fuel ratio. If you mo e Vtec to about 4200-4500 instead of 5200. It smooths out the power bump plus you usually can get an extra 10-15 hp from the engine.

 

A little more practice goes a long way too.

of gr

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Thank you everyone, I learn each time I come to this site. I think tweaking the v-tech sounds like a better option than a new engine, but spares are nice. I totally agree that 4 track days totaling 510 miles is not nearly enough experience, several of the people at the track have been racing for years and they say they are still learning, I have a long way to go. I really believe in the quality and reliability of the f20c and will probably stay with one of the versions when I build my own personal 7.

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