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

[slngsht]

Didn't West Texas go the supercharger route, with the result that his Ultralight was transformed: into an Ultra-unreliable:)?

 

I'm not sure if they had much engine trouble, but the rear end was driving them :willy: for One Lap.

 

I think that has alot to do with just getting the car together right before the event.

 

Come to think of it, a Procharger just might fit in my engine compartment [open browser, type www.ebay.com... ]

[WestTexasS2K]

Didn't West Texas go the supercharger route, with the result that his Ultralight was transformed: into an Ultra-unreliable:)?

 

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. Out of all this we are still running the same brake pads that we started the year with, the car still has the same spark plugs that I put in it 2 years ago. I did change the oil once this year and cleaned the air filter.The only problem we had was blowing up rear diffs we went thru 3 differentials during the 1 Lap. That has been fixed by going to a bigger diff no problems since then. I wouldnt hessitate for a second to jump in and drive anywhere in the country in the morning.

 

I will be going to the drag strip on the 15th to see if I can get that 11.80 pass at 128mph. If I had some drag radials I might could go low 11 to high 10s. I have run 12.30 prior to supercharging with a 2.4 60' times that means alot of spinning coming out of the hole. I actually spin in the first 3 gears if I am not careful with the thin aluminum pedal on the right. 60' times should be in the 1.60 range. Rest assured I will have slicks for the road coarse and drag radials for the strip at RunNGun.

[WestTexasS2K]

I hear that Jerry Fink from Laminar Concepts has a new car that he is bringing to Run and Gun. It has the LS7 corvette engine. He is putting 550hp to the rear wheels. I would imagine that car will be a land based rocket. His 400 hp 3 rotor rotary last year was spinning coming down the straight at 130 mph. It was wicked fast.:crazy: :crazy:

[Maverick1]

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

[BobDrye]

Kevin passed a Porsche Gt3 down the long straight at over 163 mph.

 

You left out the part about the rear of the car getting loose above that speed.

 

Loren, I've never meet you, but the 2 weekends that I spent with 7evin I didn't notice the tennis balls between his legs.

 

I finally got tags for my car today and drove it on the street about 200 miles. When it's on boost I think that 3rd gear (71 mph to 103 mph) is a little more than 1 second. I did not data log so I don't know the real figure or boost level.

[WestTexasS2K]

.

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

 

I have no idea how mine would compare to the CSR260 to tell the truth I know nothing about the specs of that car. I assume it is a 260 hp version and that is probably at the engine not the wheels. My car is probably heavier because of all the accessories for the supercharger and one lap stuff I have probably added 80 lbs to my car with the trailer hitch extra wiring and supercharger accessories. My car is 1420lbs no driver and 8gal of fuel if memory serves me. My car is fairly well sorted but I am new to the racing stuff only been doing it about 1.5 years so suspension tuning is far from my forte. I am still running the same shocks and springs I bought when I built the car. I did get the shocks retuned but I think that they are worse than before. I just mash the gas stomp the brake and turn the wheel. Caveman style:jester:

 

Your drag strip time and speed are a little unusual. It must have hooked really well out of the hole. Rear engine helps you there, but the top speed is bit slower it must haved run out of gearing. What gear and rpm are you in at the finish? I am in 4th at 9k when I cross so my gearing is perfect for the strip, on my 12.30 my mph was 123 but that was before it was supercharged I have no idea what it runs with the blower. I only had 2 passes on the 1 lap the first blew the rear on the 2-3 shift and the second pass my blower belt had come off and I didnt know it. I am running a good 105 more hp and about 60 more ft/lb of torque now. So I think low 11s or high 10s are a good possibilty if I can hook up.

[WestTexasS2K]

[b

I finally got tags for my car today and drove it on the street about 200 miles. When it's on boost I think that 3rd gear (71 mph to 103 mph) is a little more than 1 second. I did not data log so I don't know the real figure or boost level.

 

Hey your car is sounding like a beast. Your up in the 5-600hp range arent yeah? 7evin said it is going to be a rocket when you get the kinks worked out. I hope we can meet up somewhere so you can take me for a ride. That way I will know what its like to have a fast car.

[slngsht]

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

 

Agreed with WestTexas... your trap speed seems low for your ET. Stock C5 Z06 vettes normally run in the 114-116 range with 12.4 - 126 ET.

[BobDrye]

 

Hey your car is sounding like a beast. Your up in the 5-600hp range arent yeah? 7evin said it is going to be a rocket when you get the kinks worked out. I hope we can meet up somewhere so you can take me for a ride. That way I will know what its like to have a fast car.

I would like to meet, but I don't think that it will happen this year (too many conflicts). I’m going to try to meet with 7evin in Costa Rica early next year (I’m hoping to get him to rent a dirt bike with me). Let's put our calendars together!

[WestTexasS2K]

I would like to meet, but I don't think that it will happen this year (too many conflicts). I’m going to try to meet with 7evin in Costa Rica early next year (I’m hoping to get him to rent a dirt bike with me). Let's put our calendars together!

That will be a fun trip. 7evin knows Costa Rica pretty well. He is a good bike rider as well. Maybe I can come down there too. We can rent some bikes and go ride in the rain forest.

[BobDrye]

About 25 months ago I spent 10 days in Costa Rica. I left the airport with just a backpack. I took a taxi for a 45 minute drive to pickup the bike. I spent the next 10 days on the South West coast. I stayed out of the big towns and just enjoyed nature (back roads, mud, mountains, screaming back at howler monkeys, etc. The 10 days, air fair, motorcycle rental, food, lodging, food cost about $1000.00

[Keith]

I'd believe the trap speed of the Atom. Maverick's car is a 240 (claimed crank hp) and at 100+ mph the aero really comes in to play. There's more exposed tubing (bad) and more surface area (bad) on an Atom than on an Ultralite. I have the acceleration data from my car (148 at the wheels, call it 175 at the crank) and it really suffers above 80 mph. That's why the surge of acceleration from the S2000 motor when it hit the second cam profile at 100 mph really impressed me.

 

Yes, a Caterham CSR 260 makes 260 hp at the crank. I think they generally do put down faster times than Atoms in the various EVO tests, but I'd have to pull out my back issues to determine that. The lap record at EVO's track is held by the Caterham R500 Evo, which has about 530 hp per tonne and a long history of competition. The same car also held the 0-100-0 world record until an Ultima took it. So it's quite plausible that the CSR260 would be faster around the Top Gear track than the Atom. Caterhams are bred for the track.

[WestTexasS2K]

I'd believe the trap speed of the Atom. Maverick's car is a 240 (claimed crank hp) and at 100+ mph the aero really comes in to play. There's more exposed tubing (bad) and more surface area (bad) on an Atom than on an Ultralite. I have the acceleration data from my car (148 at the wheels, call it 175 at the crank) and it really suffers above 80 mph. That's why the surge of acceleration from the S2000 motor when it hit the second cam profile at 100 mph really impressed me.

 

Yes, a Caterham CSR 260 makes 260 hp at the crank. I think they generally do put down faster times than Atoms in the various EVO tests, but I'd have to pull out my back issues to determine that. The lap record at EVO's track is held by the Caterham R500 Evo, which has about 530 hp per tonne and a long history of competition. The same car also held the 0-100-0 world record until an Ultima took it. So it's quite plausible that the CSR260 would be faster around the Top Gear track than the Atom. Caterhams are bred for the track.

 

You make a good point about that open chassis, it catches alot of air and would probably accounts for the slower trap speed.

 

Maverick do you know what your 60' times were on your best run?

 

Keith you should drive it now. If you thought it was good before it awesome now. The extra 100hp is all in the 5500-9000 range right where Vtec kicks in. Its kinda like using Nitrous when it hits.

[Maverick1]

Here is the time slip from my first run. I was in the left lane.

Due to the wedge shape of the Atom it is not very aerodynamic so as the speed increases the wind resistance increase even more. I would guess you guys know a lot about wind resistance also, as the 7 shape is not much better than the Atoms. Can you imagine how our cars would perform if they were aerodynamic like the Radicals?

cheershttp://www.usa7s.com/aspnetforum/upload/1990296095_drag strip.jpg

[Davemk1]

Here is the time slip from my first run. I was in the left lane.

Due to the wedge shape of the Atom it is not very aerodynamic so as the speed increases the wind resistance increase even more. I would guess you guys know a lot about wind resistance also, as the 7 shape is not much better than the Atoms. Can you imagine how our cars would perform if they were aerodynamic like the Radicals?

cheershttp://www.usa7s.com/aspnetforum/upload/1990296095_drag strip.jpg

 

Nice R/T !

 

Dave

[AtomFest]

Here's the latest on a customer modified V8 Atom including a build log and a short video of the first engine start. http://www.dpcars.net/atom.htm

The engine/trans weighs less than the current 4 cylinder options and produces approximately 375 HP

 

This COULD become a production option in the future.

[Keith]

"Obviously pricing has not been set but I would say that this powertrain package would add roughly $45K to the cost of an Atom, give or take a few."

[WestTexasS2K]

Here's the latest on a customer modified V8 Atom including a build log and a short video of the first engine start. http://www.dpcars.net/atom.htm

The engine/trans weighs less than the current 4 cylinder options and produces approximately 375 HP

 

This COULD become a production option in the future.

 

 

I have been following the build logs at Dpcars for a couple of years. That set up should be very interesting combination. That will be a hot set up for those with a little deeper pockets. I think that engine runs in the 20k range not to mention the transmission, headers etc. He is planning on installing that in his little awd track car. I dont know how he walks with balls that big. Doesnt his track car weigh about 800 lbs with 375 hp.

 

I know there a few 7s in UK running that engine. The USA7s tour of 06 had one join them, he still had some tuning issues but the potential is awesome. The Capriata uses the same engine as well. Hopefully as the production ramps up on those the price will creep down.

[WestTexasS2K]

Here is the time slip from my first run. I was in the left lane.

Due to the wedge shape of the Atom it is not very aerodynamic so as the speed increases the wind resistance increase even more. I would guess you guys know a lot about wind resistance also, as the 7 shape is not much better than the Atoms. Can you imagine how our cars would perform if they were aerodynamic like the Radicals?

cheershttp://www.usa7s.com/aspnetforum/upload/1990296095_drag strip.jpg

 

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:

[Keith]

Not the same engine, but a similar engine. The idea of a V8 built out of two bike engines seems to have occurred to a number of people at the same time The one being used in the dp Atom is a US-built design, the one on the USA tour was an RST and the Capriata is probably built by hand by Tibetian monks.

 

Most of the cars on the USA Se7ens tour had tuning issues when they came through Colorado. Apparently altitude changes aren't taken into consideration for a lot of UK tuners.