A video of my RX7 doing 300 kph (188 mph)...
#129
Howard, how does the R1 or 99 lip influence the FD's aerodynamics?
I have the 99 lip and installed a 71" double decker "rice" wing on my car with custom stands that clear the wing over the roofline.
Nothing else has changed on the car.
I've taken the car up to 140MPH and the rear just feels more stable and planted.
I'm concerned about the front lift and would like to know if the 99 lip may have some benefits in that area.
I have the 99 lip and installed a 71" double decker "rice" wing on my car with custom stands that clear the wing over the roofline.
Nothing else has changed on the car.
I've taken the car up to 140MPH and the rear just feels more stable and planted.
I'm concerned about the front lift and would like to know if the 99 lip may have some benefits in that area.
#130
Originally posted by tRIcKI^
....one of the advantages of a porshe is that the aerodynamics get better the quicker you get (or so they say) my fd just starts shaking like sh*t when i exceed about 220km/h
....one of the advantages of a porshe is that the aerodynamics get better the quicker you get (or so they say) my fd just starts shaking like sh*t when i exceed about 220km/h
Not Cd.
#132
Racing Rotary Since 1983
iTrader: (6)
Joined: Oct 2001
Posts: 6,135
Likes: 563
From: Florence, Alabama
caped crusader...
depending on the angle of incidence your rear wing can of course be downforce, upforce or noforce. and of course you know that.
as to the r1 splitter (front spoiler). it is highly effective in 2 ways:
it lowers the cd because it channels air away from going under the car.
it provides additional front bite for trim at corner entry.
it really is amazing what a flimsy piece of plastic can do. the rear deck spoiler on my GT3 RX3SP was pop riveted on and weighed at most 2 pounds. during one qualifying session at Road Atlanta we decided to remove it for a bit more straightline speed.
the car was undriveable at the times i had been running. it would not stick at the end of the back straight and wouldn't go thru the esses on the other side worth a dam. back on went the spoiler.
i probably could have run as fast without it but it would have required different springs etc.
howard coleman
depending on the angle of incidence your rear wing can of course be downforce, upforce or noforce. and of course you know that.
as to the r1 splitter (front spoiler). it is highly effective in 2 ways:
it lowers the cd because it channels air away from going under the car.
it provides additional front bite for trim at corner entry.
it really is amazing what a flimsy piece of plastic can do. the rear deck spoiler on my GT3 RX3SP was pop riveted on and weighed at most 2 pounds. during one qualifying session at Road Atlanta we decided to remove it for a bit more straightline speed.
the car was undriveable at the times i had been running. it would not stick at the end of the back straight and wouldn't go thru the esses on the other side worth a dam. back on went the spoiler.
i probably could have run as fast without it but it would have required different springs etc.
howard coleman
#135
caped crusader...
depending on the angle of incidence your rear wing can of course be downforce, upforce or noforce. and of course you know that.
as to the r1 splitter (front spoiler). it is highly effective in 2 ways:
it lowers the cd because it channels air away from going under the car.
it provides additional front bite for trim at corner entry.
it really is amazing what a flimsy piece of plastic can do. the rear deck spoiler on my GT3 RX3SP was pop riveted on and weighed at most 2 pounds. during one qualifying session at Road Atlanta we decided to remove it for a bit more straightline speed.
the car was undriveable at the times i had been running. it would not stick at the end of the back straight and wouldn't go thru the esses on the other side worth a dam. back on went the spoiler.
i probably could have run as fast without it but it would have required different springs etc.
howard coleman
which one works better the r1/r2 or the one off the 99 and up?
depending on the angle of incidence your rear wing can of course be downforce, upforce or noforce. and of course you know that.
as to the r1 splitter (front spoiler). it is highly effective in 2 ways:
it lowers the cd because it channels air away from going under the car.
it provides additional front bite for trim at corner entry.
it really is amazing what a flimsy piece of plastic can do. the rear deck spoiler on my GT3 RX3SP was pop riveted on and weighed at most 2 pounds. during one qualifying session at Road Atlanta we decided to remove it for a bit more straightline speed.
the car was undriveable at the times i had been running. it would not stick at the end of the back straight and wouldn't go thru the esses on the other side worth a dam. back on went the spoiler.
i probably could have run as fast without it but it would have required different springs etc.
howard coleman
which one works better the r1/r2 or the one off the 99 and up?
#136
which one works better the r1/r2 or the one off the 99 and up?
did that make sense?
#137
I'm wondering if the 99 front spoiler with the 93-95 usdm bumper is acutally worse then the 93-95 front lip in terms of providing front downforce since it's not made to fit our bumpers but rather the 99 and up bumpers..hope that makes sense.
#138
Aerodynamics of 1999 RX-7...
Aerodynamics of 1993-1995 RX-7...
Looks like the 1999 front lip has about half the lift of the 1993-1995 version, but I don't know if that's dependent on having the 1999 front bumper or not. I doubt it.
The RX-7 may now be fitted with an adjustable-rake rear wing with five alternate angles. At the standard one-degree rake, the front lift coefficient is 0.045 and the rear 0.000. At the extreme fourth setting of 14.5 degrees, the car generates a front lift coefficient of 0.053 and a negative rear lift coefficient of -0.075, pushing the rear end firmer onto the road surface.
Source: http://www.rx7.org/Robinette/sae_article.htm
Source: http://www.rx7.org/Robinette/sae_article.htm
Base - Cd: 0.29, lift coefficient FR: 0.16, lift coefficient RR: 0.08
R1/R2 - Cd: 0.31, lift coefficient FR: 0.10, lift coefficient RR: 0.08
Source: http://www.scuderiaciriani.com/rx7/wing/
R1/R2 - Cd: 0.31, lift coefficient FR: 0.10, lift coefficient RR: 0.08
Source: http://www.scuderiaciriani.com/rx7/wing/
#141
Racing Rotary Since 1983
iTrader: (6)
Joined: Oct 2001
Posts: 6,135
Likes: 563
From: Florence, Alabama
i would be quite interested as to the 99's actual frontal area and overall drag coefficient. i'll bet it takes more hp to move it thru the air.
the conversion of rear lift to zero or below costs drag. i would rather tune the bite thru spring rate than bolt on drag.
thanks for the interesting numbers. we now need frontal area and drag coefficient for the 99 RX7
howard coleman
the conversion of rear lift to zero or below costs drag. i would rather tune the bite thru spring rate than bolt on drag.
thanks for the interesting numbers. we now need frontal area and drag coefficient for the 99 RX7
howard coleman
#142
This is unscientific, but........
....when I made the big performance jump that included the '99 splitter to a Touring that had nothing, I tested on a brand new four mile length of smooth concrete 4-lane - mild, windless summer sunset and no wind - with a 140 mph run. The splitter definitely eliminated yaw and settled and planted the nose. The thing works well.
....when I made the big performance jump that included the '99 splitter to a Touring that had nothing, I tested on a brand new four mile length of smooth concrete 4-lane - mild, windless summer sunset and no wind - with a 140 mph run. The splitter definitely eliminated yaw and settled and planted the nose. The thing works well.
#143
The RX-7 may now be fitted with an adjustable-rake rear wing with five alternate angles. At the standard one-degree rake, the front lift coefficient is 0.045 and the rear 0.000. At the extreme fourth setting of 14.5 degrees, the car generates a front lift coefficient of 0.053 and a negative rear lift coefficient of -0.075, pushing the rear end firmer onto the road surface.
Source: http://www.rx7.org/Robinette/sae_article.htm
Source: http://www.rx7.org/Robinette/sae_article.htm
The problem I have with using this little fact for weighting the aerodynamic value of the 99 front end is that it appears to be dealing only in the rear wing. It doesn't mention if those front lift values are taking into account the effect the 99 front lip would have on it. They may have just been testing one aero piece at a time when coming up with those facts. Good hard facts about the 99 wing no doubt, but with all the aero work that went into these cars it would be hard to convince me that for a little style on the front Mazda sacrificed .043 front lift.
#144
Originally Posted by FDreaming
Good hard facts about the 99 wing no doubt, but with all the aero work that went into these cars it would be hard to convince me that for a little style on the front Mazda sacrificed .043 front lift.
#146
While the aero work is w/o peer, Mazda engineers had no problem undersizing the runnng gear and choking the car with that dreadful I/C, intake, and twin cat exhaust......
It's OK that are some areas for improvements here and there, even in the aero dept.
It's OK that are some areas for improvements here and there, even in the aero dept.
#147
Full Member
Joined: Nov 2002
Posts: 172
Likes: 0
From: FL
Originally Posted by diyman25
DID not see the video yet but great job, doing 300km with out help of BIG spoiler. 3 gen was not very great design on areodynamic. BTW did any one know stock 3 gen can run over 165mile +. FEW year agao Motor trend do a top speed test on all the high performance car at that time. FD was the only japanese car run over 155 mile stock..
OH I just saw the video. very cool, it would be better if you have camera mount
OH I just saw the video. very cool, it would be better if you have camera mount
Mustangs of late 80's needed 400 hp to hit the 150 mark, and if they tried to curve at that speed they'd float off the road.
#148
That is damn impressive. Scary as hell but impressive nonetheless. But I have one comment. The speed indicated on the speedometer is going to anything BUT accurate **IF** anything in the drivetrain has been changed. Drop a short ratio fifth gear or short R&P gears and the *indicated* speed will be optimistically high. However, even with his tire size being a tad off, if using the stock gearing it should be with 5%-10% of an actual speed. And VERY impressive.
Regards
Crispy
PS I use a 99 splitter and 99 rear wing and my car is so stable at 145mph on the track I could take my hands off the wheel and wave to a flagger if I felt so inclined
Regards
Crispy
PS I use a 99 splitter and 99 rear wing and my car is so stable at 145mph on the track I could take my hands off the wheel and wave to a flagger if I felt so inclined
#149
Originally Posted by jimlab
I think you mean improved (decreased) front lift... lower numbers are better. 0.045-0.053 < 0.10