Anyone read the latest Grassroots Motorsports? 7 vs Atom...

[WestTexasS2K]

I knew there were a few variations being built but I wasnt sure which one he was using.

[Maverick1]

 

Dang Maverick that is an awsome RT for your first time at the drag strip. Someone must have given you a few tips before hand. The 60' time is good for street tires too. That looks like a good job of driving to get it hooked up and not overpower the wheels to badly. I bet if you put some drag radials on there you could get in the 1.60s and down to 11.40 or lower range. :thumbs: :thumbs:

Your right I did get a tip. They told me not to wait for the green light to flash, but to let her go after the 3rd yellow and by the time I reacted I would have a good time. It's still not that easy as my other runs were in the low 12's all with missed shifts. Live and learn

cheers

[slngsht]

another :thumbs: on your reaction time and 60' time.

[WestTexasS2K]

WestTexasS2k, how would your 7 stack up to the Caterham CSR260 from a performance, acceleration, handling standpoint?

I saw a video where they claim a CSR260 set the fastest time round the Top Gear test track. Not sure if it is legit but it did look real.

About a month ago I took my Atom to the drag strip, and it was the very first time I have run any car at a strip so talk about being a complete rookie. I even missed the staging lights and had to back up and reset.

I set my best time on my first run....I did 11.9 seconds at 114.8 mph, this with crapy street tires on it. I probably could have done a little better with a set of proper R compound tires. It was a lot of fun.

cheers

 

Maverick I did some research on the Caterham models and the listd specs compared to mine.

 

Caterham CSR 260 Ultralite S2k Supercharged Ultralite XR7 (new Model)

Wheel base 91.14 88 88

front track 59.25 59.5 59.5

rear track 57.67 61 61

length 129.9 124 124

width 66.3 68 68

Ground clearance 4 4 2.5

turning radius 36' 26' 26'

weight 1267 1380 1047

hp 260 340 240

hp per lb 4.8 4.17 4.3

 

brakes ? 12" all 4 12" front 10' (inboard)

wheels 15" 17" 17"

suspension

front inboard shock conventional inboard

rear independent independent independent

 

 

So on paper they are pretty close. The major difference is the power difference on the supercharged car. Now I have never driven a Caterham but I am sure they are a fine driving machine. I would suspect it is a bit more of a refined drive over the Ultralite. I think this is mostly due to Ultralite uses rod ends on all the suspension where most of the other cars uses a bushing of some sort on the A arms and suspension pieces. Plus they have been building them for 48 years compared to the Ultralites 6years.

[Maverick1]

 

Maverick I did some research on the Caterham models and the listd specs compared to mine.

 

Caterham CSR 260 Ultralite S2k Supercharged Ultralite XR7 (new Model)

Wheel base 91.14 88 88

front track 59.25 59.5 59.5

rear track 57.67 61 61

length 129.9 124 124

width 66.3 68 68

Ground clearance 4 4 2.5

turning radius 36' 26' 26'

weight 1267 1380 1047

hp 260 340 240

hp per lb 4.8 4.17 4.3

 

brakes ? 12" all 4 12" front 10' (inboard)

wheels 15" 17" 17"

suspension

front inboard shock conventional inboard

rear independent independent independent

 

 

So on paper they are pretty close. The major difference is the power difference on the supercharged car. Now I have never driven a Caterham but I am sure they are a fine driving machine. I would suspect it is a bit more of a refined drive over the Ultralite. I think this is mostly due to Ultralite uses rod ends on all the suspension where most of the other cars uses a bushing of some sort on the A arms and suspension pieces. Plus they have been building them for 48 years compared to the Ultralites 6years.

Thanks for the info WestTexas and for the complement slngsht, beginners luck I guess.

I think your car should be able to hit 60mph in under 3 seconds from the stats you have listed above. My Atom is supposed to hit 60mph in 2.8 seconds and your car has much more hp than mine and our cars roughly weigh the same at 1,350-1,400 pounds. Have you ever tested out your 0-60 times?

Cost wise, probably going with the Ultralite S2k is the better choice as the Caterham CSR260 will cost around $69,000 and that's before any options. What would an Ultralite S2k and the S2K supercharged sell for?

I am thinking of getting some kind of lap timer for the track, because that is really the only way to see if I'm improving as a driver. Do you have any suggestions on a lap timer. There is one called Traqmate and one called performanceBox, both are GPS based units.

Most Atom owners opted for the Yokohama AO-48 R compoud tires, however when my car was being built there was a shortage of the AO-48's so I got the Yoko ES-100's which I don't really like on the road or track. I've been thinking of getting either the AO-48's or the Toyo Proxes RA-1's. Do any of you gentlemen have any experience with the RA-1's, or do you have a suggestion for tires for my Atom for the track? I've read up on them and most give them a great rating and say they don't degrade with too many heat cycles as other tires do.

cheers

[WestTexasS2K]

Maverick A new Ultralite runs 38k and the supercharger adds 5k to the tab. So 43k should get you there. I built mine from a kit and have a little over 30 in it now. I think my car is capable of 2.8 second 0-60, problem is getting traction. When companies do these test I dont think they are using street tires.

 

As far as tires I have never run any R compound tires. I assume you want something DOT for street use as well. The RA1 have been around awhile and seems to be a popular choice. Perelli Corsa are good tire. Michelin pilot cup are supposed to be good too. Tire Rack has a tire testing section that usually is full of good info. You might check it out and see if sheds any light. I am sure the members here will have a few suggestions. I assume that the Atom is easy on tires like the 7s due to light weight. It takes awhile to wear them out so R tires last fairly long even on a road car.

 

As far as lap timers my car has the AIM Mycron 3 digital dash. It has a built in lap timer which does really help when you are trying different lines on the track. This way you have instant feedback to see if what you doing is improving or worsening your times. It was really beneficial at RunNGun last year. I could try different breaking points and corner entry points and know if worked or not. All the people running had timers that recordered their lap times but they had to wait to find out the fastest lap was. Bad thing is they would know the lap times but no way of knowing which lap time went with a certain change.

 

With track mapping you can go back and look at breaking points and see corner entry and exit speeds lateral G and so on. I have heard that the traqmate is good I know I see it in alot of cars at the track. I have heard it is easy to diagnose the data. The AIM unit I have is not very user friendly but is very accurate when you figure it out. It is not GPS based.

[slngsht]

Getting under 3 seconds 0-60 on street tires will be tough - at least for a car with reasonably balanced weight distribution.

 

This was a back road 0-60 attempt in my car... pretty worn out nitto R compound tires, relatively slippery pavement (glazed over look). Unfortunately I run out of gear at 57 MPH. D'oh. also, on this run I don't think I quite made it to 60. looks like wheel spin between 57 and 60.

http://www.usa7s.com/forum/uploads/slngsht/0to60_1.jpg

[Kitcat]

RA 1's are great. They stick well and don't wear out quickly, at least as far as race tires go. I have put 1500 street mile on a set I just bought and another 200 track miles, with no serious wear yet.

 

If you want the ultimate in performance, maybe try Hoosiers. If you are competing in SCCA events or other timed competitions, the few tenths you shave off your time are worth the extra bucks and rapid wear.

 

If you are just a track day junkie having fun, the the RA-1's offer a nice compromise between grip and wear. And, on my car, they were quieter and the ride wasn't as harsh as it was on the Michelin Pilots, tho on a Seven, it's hard to notice such things:).

[Keith]

I run the RA1. The ones I had on my car at the Atom test were a couple of years old, having withstood a huge amount of abuse including a drifting session by Car and Driver. They just work and work and work.

[slngsht]

I sold my RA1s on my old wheels to Robert U on the forum. I will be going back to them, or the 888s as soon as I finish off my Nittos

[Maverick1]

Maverick A new Ultralite runs 38k and the supercharger adds 5k to the tab. So 43k should get you there. I built mine from a kit and have a little over 30 in it now. I think my car is capable of 2.8 second 0-60, problem is getting traction. When companies do these test I dont think they are using street tires.

 

As far as tires I have never run any R compound tires. I assume you want something DOT for street use as well. The RA1 have been around awhile and seems to be a popular choice. Perelli Corsa are good tire. Michelin pilot cup are supposed to be good too. Tire Rack has a tire testing section that usually is full of good info. You might check it out and see if sheds any light. I am sure the members here will have a few suggestions. I assume that the Atom is easy on tires like the 7s due to light weight. It takes awhile to wear them out so R tires last fairly long even on a road car.

 

As far as lap timers my car has the AIM Mycron 3 digital dash. It has a built in lap timer which does really help when you are trying different lines on the track. This way you have instant feedback to see if what you doing is improving or worsening your times. It was really beneficial at RunNGun last year. I could try different breaking points and corner entry points and know if worked or not. All the people running had timers that recordered their lap times but they had to wait to find out the fastest lap was. Bad thing is they would know the lap times but no way of knowing which lap time went with a certain change.

 

With track mapping you can go back and look at breaking points and see corner entry and exit speeds lateral G and so on. I have heard that the traqmate is good I know I see it in alot of cars at the track. I have heard it is easy to diagnose the data. The AIM unit I have is not very user friendly but is very accurate when you figure it out. It is not GPS based.

Thanks for the tire info guys, I think the RA-1's are the ones I will try next. I think they will be the best R compound choice for running both on the street and the track. From what I have read the AO-48's would wear out a lot sooner and I'm not sure they would give me any more performance, and definitely are not good in the wet.

WestTexas, don't you think you would could benefit from going with an R compound tire for the track?? When I flew out to test drive the Atom the demo car had R compound tires on it and I can definitely notice the difference between street tires and R compound. With R compound tires you would definitely improve your lap times.

Cheers™

 

[7evin]

 

Well Kitcat I think you got some bad info on our car. We did go with a Vortech supercharger and intercooler on our little 2.0. We are making 300hp at the rear wheels with 9lbs of boost. As far as turning it into Ultra unreliable we drove the car 5k+ miles pulling a 1400 pound trailer at 80 plus miles an hour, ran 18 track events across the country in 1 week. followed that up with a 2 days of pounding at Road Atlanta at Panoz day where we were faster than all but 2 cars a fully race preped viper and a corvette Z06 running 600hp and 12 slicks all the way around. Mind you we were still running street tires left over from the one lap Bridestone RE01. Kevin passed a Porsche Gt3 down the long straight at over 163 mph.

 

Small note to the facts, The Porsche GT3 RS was running 600 hp and club tires ( kind of like racing slicks) he claimed he was running 163 mph when I passed him. He was a little floored that what he had called a cute car earlier that day would pass him later that afternoon in a section of the track where his car works its

magic. (the long back stretch)

I have no idea how fast I was going, I refused to look after I went thru 150.

I was just hoping the car would stay on the ground.

I don't think Brian intended the S2K to ever start knocking on the door of 200 mph.

But with his new secret aerodynamic upgrade that could be possible.

 

Bob I can't wait to ride in your car.

 

I never did get an answer about the top speed of the atoms on the full course at VIR....

 

Cheers

 

[AtomFest]

I never did get an answer about the top speed of the Atoms on the full course at VIR....

 

Just checked my Traqmate files. Our best top was at the end of the main straight - 128 mph. We dealt with two limitations: of course the aero was bad, but on the back straight we topped 4th gear at 7,000 RPM and then had to go to 5th (overdrive). The RPMS dropped to 5,000 and our acceleration pretty much died. Full course times were 2.13 in the older car and 2.16 in the new one. Both cars are 245 HP spec. Peak speed through the climbing esses was 118. This was our first visit to VIR.

 

http://i66.photobucket.com/albums/h269/SuperCobraBuilders/UTC/image003.jpg

 

http://i66.photobucket.com/albums/h269/SuperCobraBuilders/UTC/image002.jpg

 

 

[WestTexasS2K]

Thanks for the tire info guys, I think the RA-1's are the ones I will try next. I think they will be the best R compound choice for running both on the street and the track. From what I have read the AO-48's would wear out a lot sooner and I'm not sure they would give me any more performance, and definitely are not good in the wet.

WestTexas, don't you think you would could benefit from going with an R compound tire for the track?? When I flew out to test drive the Atom the demo car had R compound tires on it and I can definitely notice the difference between street tires and R compound. With R compound tires you would definitely improve your lap times.

Cheers™

 

Maverick my car would certainly benefit from R compound tires. Several reasons why I havent used them. 1 I am learning how to drive and sticky tires tend to save you butt when you drive badly. I have had several instructors tell me to stay with street tires until I can become consistent and smooth. 2nd reason is our main event is the 1 Lap of America we are restricted to 140 or greater wear tires so the more practice with the tires we have to use the better. It is difficult to go from R compounds back to street tread and not over cook things. 3rd is money I just never seem to have a spare 1k lying around that isnt needed worse else where. But thanks to my FANTASTIC SPONSOR HARMONY CONE :hurray: I will get a new set just in time for RunNGun.

[Maverick1]

 

Maverick my car would certainly benefit from R compound tires. Several reasons why I havent used them. 1 I am learning how to drive and sticky tires tend to save you butt when you drive badly. I have had several instructors tell me to stay with street tires until I can become consistent and smooth. 2nd reason is our main event is the 1 Lap of America we are restricted to 140 or greater wear tires so the more practice with the tires we have to use the better. It is difficult to go from R compounds back to street tread and not over cook things. 3rd is money I just never seem to have a spare 1k lying around that isnt needed worse else where. But thanks to my FANTASTIC SPONSOR HARMONY CONE :hurray: I will get a new set just in time for RunNGun.

West when you compete in RunNgun and the lap of America has an Ultima GTR ever competed in those events. It seems like a natural for that kind of event.

Cheers™

[7evin]

West when you compete in RunNgun and the lap of America has an Ultima GTR ever competed in those events. It seems like a natural for that kind of event.

Cheers™

 

 

Here are the results from 06 from the one lap website. One Lap

 

Overall Results

 

31 50 World Class Mot Ultralite SSGT2 SB 4740

Loren Edwards, Kevin Boulton

32 17 Ultima GTR SSGT1 BB 4695

Carl Warren, Sam Kimberley-Bryant, Don Kahn

 

Of course the other Ultima ran 5 th overall

 

This year 07

 

The GTR ran 4th and a Dodge Neon ran 5th.....

4 26 Ultima GTR SSGT1 BB

Carl Warren, Sam Kimberley-Bryant

5 51 Dodge SRT-4 MidPri Sed

Douglas Wind, Devin Clancy, Ken Brewer

 

 

We were 19th, .... Yeah, I know, beat by a Neon....

 

At least we were not driving a Viper or something Macho...

 

As westTx can attest it was one very bad a$$ Neon and they knew how to drive.

In the One Lap if you are running top 10 you are doing something right, BIG time.

Sam drives the 24 hours of Lemans.

 

On the grid at Mid America 06, Loren was driving.

24 50 World Class Mot Ultralite SSGT2 SB 5:25.501

Loren Edwards, Kevin Boulton

37 17 Ultima GTR SSGT1 BB 5:38.504

Carl Warren, Sam Kimberley-Bryant, Don Kahn

 

http://usa7s.com/aspnetforum/upload/275548711_pics 008.jpg

 

Thanks for the info about the results at VIR. The car does look great on the track.

 

I did not mean to butt in, but I think Dr. Demento ( AKA WestTx) is out for the night.

Cheers

 

[Kitcat]

Driver talent is a huge variable at the One Lap, its not all car. Many people just do it for fun and have limited on-track experience/talent. Others, like Danny Popp, in his various 'Vettes, are really pro-level drivers.

 

Danny, who I auto-x'd with in Cincy for years, has numerous SCCA solo national championships under his belt and owns a variety of lap records on various road courses. So any car he drives is going to be fast, or at least faster than anyone might expect.

 

Danny once set up a local auto-x course and then did a practice lap in it to see how it flowed. His time, in his beat-up pickup with about 200 cones still in the bed, was comparable to my best lap in my race prep'd, race-tire shod Miata. Truly a humbling experience.

[7evin]

Driver talent is a huge variable at the One Lap, its not all car. Many people just do it for fun and have limited on-track experience/talent. Others, like Danny Popp, in his various 'Vettes, are really pro-level drivers.

 

Danny, who I auto-x'd with in Cincy for years, has numerous SCCA solo national championships under his belt and owns a variety of lap records on various road courses. So any car he drives is going to be fast, or at least faster than anyone might expect.

 

Danny once set up a local auto-x course and then did a practice lap in it to see how it flowed. His time, in his beat-up pickup with about 200 cones still in the bed, was comparable to my best lap in my race prep'd, race-tire shod Miata. Truly a humbling experience.

 

The guy is quite amazing to say the least. I have to agree with you about the driver talent. We have watched drivers

push cars to levels that were beyond belief.

I would love to see Danny on the track in a Seven or Atom. Better yet I would like to be in the pass seat.

I'm sure your heart would skip a few beats.

 

Cheers

[Kitcat]

I rode with Danny in his 'Vette at Putnam Park race track at a track day 2 years ago. He was turning 1'15's (his best is 1'12'). I was doing 1'24's in my Evo. I would estimate I was doing 1'28 in my Seven there this summer. I was seasick when I got out of Danny's car.

[WestTexasS2K]

Danny Pop is a driving machine. The man is just incredible. we wanted him to drive our car at the end of 1 Lap 06 to get his impressions butt couldnt track him down.