Gunfight At The O K Corral
05-30-08, 01:59 PM
#52
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
weight:
rotary FD challenger 2918 (includes 4 gallons of methanol onboard)
LS2 FD challenger 2883 (2% less rear weight)
LS2 FD challenger:
SAE HP 373
SAE TQ 382
hc
rotary FD challenger 2918 (includes 4 gallons of methanol onboard)
LS2 FD challenger 2883 (2% less rear weight)
LS2 FD challenger:
SAE HP 373
SAE TQ 382
hc
05-30-08, 02:15 PM
#53
Hey just wondering if you are using factory diffs in either vehicles
Stock FD diff ratio (4:10) vs a LS1 mating diff (unknown ratio "at least to me)
just wondering, because I have ridden in 7's that have a diff swap and it made quite a difference.
or is that something you think that wont matter much?
Stock FD diff ratio (4:10) vs a LS1 mating diff (unknown ratio "at least to me)
just wondering, because I have ridden in 7's that have a diff swap and it made quite a difference.
or is that something you think that wont matter much?
05-30-08, 02:22 PM
#54
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
rotary runs stock FD 4.1 gears.
challenger runs ford 8.8 rear and is being changed to a 3.9 ratio.
my rotary makes peak TQ at 6100. the LS2 is very close to upshift at this RPM. my rotary likes to run to 8000.
the cars will certainly end up in different gears on the track.
hc
challenger runs ford 8.8 rear and is being changed to a 3.9 ratio.
my rotary makes peak TQ at 6100. the LS2 is very close to upshift at this RPM. my rotary likes to run to 8000.
the cars will certainly end up in different gears on the track.
hc
05-30-08, 03:34 PM
#59
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
Shootout cars meet for the first time.
on the dyno at Beyond Redline/Green Bay/ Brett Favre was watching
to go fast you have to stop fast. stock front Stoptech left, RacingBrake right. case closed.
so many cool engineering features in this one closeup... notice alternating spokes convey heat equally from inner and outer disc surface. note air space. the rotor "floats" w the patented hardware so when the disc expands it doesn't deform. no need for ducts. 1.26 inches thick V .79. both cars will run RacingBrake four wheel systems.
nice caliper...
hc
on the dyno at Beyond Redline/Green Bay/ Brett Favre was watching
to go fast you have to stop fast. stock front Stoptech left, RacingBrake right. case closed.
so many cool engineering features in this one closeup... notice alternating spokes convey heat equally from inner and outer disc surface. note air space. the rotor "floats" w the patented hardware so when the disc expands it doesn't deform. no need for ducts. 1.26 inches thick V .79. both cars will run RacingBrake four wheel systems.
nice caliper...
hc
Last edited by Howard Coleman; 05-31-08 at 04:25 PM.
05-31-08, 03:50 AM
#62
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Do you mean to say the LS2 car is a 51%F/49%R distribution? If you have the front and rear numbers of both cars, it would be interesting to see those. Surprised to see how heavy the rotary car was... I assume all things were equal as far as fluids (except meth), driver in car, wheels, etc. for these weights? Frankly, I would have expected BOTH cars to be lighter than they are.
05-31-08, 09:03 AM
#63
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
weight details at 25 inch ride height:
rotary
weight dry 2913
rear weight 51%
inside (right) weight 51%
cross weight 51%
front 718----713
rear 713----769
LS2
weight dry 2825
49% rear weight
48% inside weight
48% cross weight
front 676----770
rear 722---- 690
//////RF was initially, and wrongly, reported as 827./////
corner weights w 33 pounds of gas onboard.
88 pound advantage over my rotary FD.
we will be doing a bit of adjusting cornerweights on the LS2, though i am not happy w the static distribution. jacking a ton of weight around w ride heights is less preferable than building it right from the start.
hc
rotary
weight dry 2913
rear weight 51%
inside (right) weight 51%
cross weight 51%
front 718----713
rear 713----769
LS2
weight dry 2825
49% rear weight
48% inside weight
48% cross weight
front 676----770
rear 722---- 690
//////RF was initially, and wrongly, reported as 827./////
corner weights w 33 pounds of gas onboard.
88 pound advantage over my rotary FD.
we will be doing a bit of adjusting cornerweights on the LS2, though i am not happy w the static distribution. jacking a ton of weight around w ride heights is less preferable than building it right from the start.
hc
Last edited by Howard Coleman; 06-02-08 at 01:48 PM.
05-31-08, 03:10 PM
#67
Racing Rotary Since 1983
Thread Starter
iTrader: (6)
"Howard, will you attempt to handicap the power of one of the cars if it turns out one has a massive dyno advantage? Or is that the point"
warren wallace asks the $64 question.
while all this has yet to be totally figured out i am most interested as to at what power level does the rotary need to run to turn similar lap times to the already power evaluated LS2.
we all probably understand that it is easily possible to mod each of the cars to monster power levels and shred the other car.
where is the balance point?
there are other interesting considerations as driveability comparisons etc.
do keep in mind that the cars will be placed on the track at maximum dual purpose state of prep. this is not about race cars. this is about going almost as fast as well prepared racecars but grocery-getter friendly.
hc
warren wallace asks the $64 question.
while all this has yet to be totally figured out i am most interested as to at what power level does the rotary need to run to turn similar lap times to the already power evaluated LS2.
we all probably understand that it is easily possible to mod each of the cars to monster power levels and shred the other car.
where is the balance point?
there are other interesting considerations as driveability comparisons etc.
do keep in mind that the cars will be placed on the track at maximum dual purpose state of prep. this is not about race cars. this is about going almost as fast as well prepared racecars but grocery-getter friendly.
hc
06-01-08, 10:29 AM
#68
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I talked to a guy who roadraced an FD against Porsches for several years at VIR, he always said it wasn't really the peak power that did him in, it was the driveability and spread of power over a large rpm band...a 13B just can't match that, but I'm still interested to see the results here
06-01-08, 10:59 AM
#69
Racing Rotary Since 1983
Thread Starter
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"it wasn't really the peak power that did him in, it was the driveability and spread of power over a large rpm band..."
actually the above is probably correct.
"a 13B just can't match that"
actually the above is incorrect.
perhaps his car couldn't match whatever he was running with but w the aid of a gearbox, or more accurately being in the right gear, my car should.
the LS2 made 382 SAE foot pounds of torque. it made 200 rwhp at 2700 RPM.
my last dyno (sep 07) i made 364 ft pounds at 6100 and 200 rwhp at around 4300RPM. i will be running a superior (FJO) fuel injector/cell by cell tuning alcohol system and be tuned a bit better. the above run was at a peak boost of 15.8.
as you can see my motor needs 1600 more RPM to make 200. i will be running at least 7500 shiftpoints where the LS2 will probably see just 6000 max.
if everything on my setup is optimised my twin TO4 setup should make 630 rwhp at 23 psi. clearly, that is not what is going to happen. i would like to be able to be tuned around one bar and run similar lap times. i will post my datalogs from all runs so everyone will know exactly what boost i ran.
as previously posted, it will be interesting to see where the balance point is.
rotaries can run w piston engines... i know as i raced against factory twin cam 4 valve toyotas, BMWs, porsches etc. the SCCA had us choked down to 38 MM venturies. we had to run between 7000 and 10,000 RPM but by running higher RPM everything worked out.
hc
actually the above is probably correct.
"a 13B just can't match that"
actually the above is incorrect.
perhaps his car couldn't match whatever he was running with but w the aid of a gearbox, or more accurately being in the right gear, my car should.
the LS2 made 382 SAE foot pounds of torque. it made 200 rwhp at 2700 RPM.
my last dyno (sep 07) i made 364 ft pounds at 6100 and 200 rwhp at around 4300RPM. i will be running a superior (FJO) fuel injector/cell by cell tuning alcohol system and be tuned a bit better. the above run was at a peak boost of 15.8.
as you can see my motor needs 1600 more RPM to make 200. i will be running at least 7500 shiftpoints where the LS2 will probably see just 6000 max.
if everything on my setup is optimised my twin TO4 setup should make 630 rwhp at 23 psi. clearly, that is not what is going to happen. i would like to be able to be tuned around one bar and run similar lap times. i will post my datalogs from all runs so everyone will know exactly what boost i ran.
as previously posted, it will be interesting to see where the balance point is.
rotaries can run w piston engines... i know as i raced against factory twin cam 4 valve toyotas, BMWs, porsches etc. the SCCA had us choked down to 38 MM venturies. we had to run between 7000 and 10,000 RPM but by running higher RPM everything worked out.
hc
06-02-08, 12:25 AM
#72
All else equal, "power under the curve" is what matters and we're talking HORSEPOWER (and gearing and driver, and other crap), not torque!!! On the track I don't think you'll be running under 4 grand anyway. You're an experieced racer... Good luck Howard, and BTW your car looks great
Last edited by mdpalmer; 06-02-08 at 12:34 AM.
06-02-08, 12:29 AM
#73
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I think this is really interesting. Any chance you guys could do a "tour" of sorts and get some more data on a few different tracks?
I'm also curious as to why the corner weights are so funky on the LS2 car. I've never been convinced the weight distribution was very good at all on them but I would not have suspected differences quite that large.
I'm also curious as to why the corner weights are so funky on the LS2 car. I've never been convinced the weight distribution was very good at all on them but I would not have suspected differences quite that large.
06-02-08, 01:38 PM
#74
Racing Rotary Since 1983
Thread Starter
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right front LS2 corner weight was transcribed incorrectly.
s/b
676 LF..770 RF
722 LR.. 690 RR
RF was initially, and wrongly, reported as 827.
above is w 33 pounds of gas onboard.
dry weight 2825
49% rear weight
48% inside weight
48% cross weight
88 pound advantage over my rotary FD.
hc
s/b
676 LF..770 RF
722 LR.. 690 RR
RF was initially, and wrongly, reported as 827.
above is w 33 pounds of gas onboard.
dry weight 2825
49% rear weight
48% inside weight
48% cross weight
88 pound advantage over my rotary FD.
hc
Last edited by Howard Coleman; 06-02-08 at 01:49 PM.
06-02-08, 02:18 PM
#75
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Is that with both cars having the same amount of GAS?
right front LS2 corner weight was transcribed incorrectly.
s/b
676 LF..770 RF
722 LR.. 690 RR
RF was initially, and wrongly, reported as 827.
above is w 33 pounds of gas onboard.
dry weight 2825
49% rear weight
48% inside weight
48% cross weight
88 pound advantage over my rotary FD.
hc
s/b
676 LF..770 RF
722 LR.. 690 RR
RF was initially, and wrongly, reported as 827.
above is w 33 pounds of gas onboard.
dry weight 2825
49% rear weight
48% inside weight
48% cross weight
88 pound advantage over my rotary FD.
hc