whats the top speed of your n/a
03-20-08, 11:31 AM
#51
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i want my car to hit at least 135 mph. but im scared it would break. i already did 100 mph though. u guys think my car can take it? i have a 88 n/a with aftermarket intake and cat back exhaust.
03-20-08, 12:34 PM
#52
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If it is not in very good shape and you thing it will break, it probably will. Your car was made to go higher speeds when new, but it all depends on the condition the the car now.
03-21-08, 02:05 AM
#53
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147ish on a back road racing a friend at around 2:30am as i was passing a house someone turned on a porch light and scared the crap out of me
he was in a 1990 dodge omni that we put a 2.2 turbo engine out of a new yorker
it HAD a T3/T4 turbo and a shelby computer from an 86 GLH-S I won with a mostly stock 86 7 haha
he was in a 1990 dodge omni that we put a 2.2 turbo engine out of a new yorker
it HAD a T3/T4 turbo and a shelby computer from an 86 GLH-S I won with a mostly stock 86 7 haha
03-21-08, 09:56 PM
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i guess so. ill try it after i get my tranny rebuilt. i think the engine is still good. im not sure though. im just gonna take it easy on her for now.
03-22-08, 08:54 PM
#56
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had my FB at 155mph, took a little bit to do, mods are holley carb and intake, e-fan, RB header, custom exhaust, centerforce II clutch, msd coils, accel wires, by the way carb was tuned for wide band
03-29-08, 04:01 PM
#57
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flame me if im wrong but provided your car has the power needed to hit top speed is that speed not determined by the transmission and other gear ratios as well as tire size. would 2 rx7s with identical transmissions, rear end, and tire sizes not have the same top speed.. give one 100 extra horsepower an it would reach that speed faster but at the end of the day 5th gear at say 8000rpm on 4.10 rear end with stock tires and matched transmissions is going to be the same isnt it?
03-29-08, 07:40 PM
#58
Top speed is limited by power rather than gearing alone. Without enough power you can not reach 8000 rpm's in 5th gear. Drag increases exponentially as speed increases requiring greater and greater amounts of power as speed increases. This is particularly noticeable over 100 mph. My race prepared E production SCCA 2nd gen will pull 10,000 rpm's in 5th with 5.12 rear or 9400 with the 4.8 rear roughly the same top speed. I am sure this is due to aerodynamics and power available.
03-29-08, 08:04 PM
#59
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Yes talk you are correct.
If you have two identical cars.. (Impossible btw) that have EXACTLY the same surface friction(paint smoothness gaps in bodylines). Same surface area, same tire pressure, lubrication levels, and viscosity. Gear wear. Drivetrain lash, compression, etc etc etc.
If EVERYTHING was identical, IE you hit copy and paste. In a science lab from the movies.
Yes they would have the same top speed.
It may be 125. It may be 150. That is a factor of getting to top speed, and having the HP to overcome drag.
BUT. For example lets say they both had a 6:12 rear gear, and top speed at 9K was 120. They both should have the stock HP to achieve that with no prolem. In a perfect cut and paste world they would get there at the same time too.
Gearing limited HP is something a LOT of RX-7 people run into with more heavily modified cars.
For example a TII with FD rims on it and stock tires would have a top speed of 188 in 5th gear at 7500 RPM.
225/50/16 Tires
4.10 Rear Gear
1st 3.483
2nd 2.015
3rd 1.391
4th 1.000
5th 0.719
Powerband 4K-7K
Idle 800
Redline 7500
................Idle..........Powerband........... ..Redline
1 Gear......4..............21...........36.......... ..39.............mph
2 Gear......7..............36...........63.......... ..67.............mph
3 Gear......10............52...........91........... .97.............mph
4 Gear......14............72...........126.......... 135...........mph
5 Gear......20............100.........175..........1 88...........mph
Is 188 Achievable for a TII?
Certainly.
If its modified to any extent of course.
I have a spreadsheet that has all the tranny ratios and rear gears, as well as a chart of all stock rim/tire sizes, as well as the ability to pop in different rim/tire combos, as well as Powerband and redline variables.
SO yes.
To answer the question. You "should" have very similar top end with identical part sister cars.
If you have the power to do it, and a lower rear gear to overcome parasitic drag, and drop the top end enough, you both should hit it easily.
IR two 89 FC TIIs with stock tires and rims. You MIGHT be able to reach top end. If they are bone stock, and high mileage? Ehh.
I dont think I would want to take someone's FC to that speed without changing the toe steer at the least.
Around 135-140 the stock FC in mint condition has a lot of tail waggle.
If you have two identical cars.. (Impossible btw) that have EXACTLY the same surface friction(paint smoothness gaps in bodylines). Same surface area, same tire pressure, lubrication levels, and viscosity. Gear wear. Drivetrain lash, compression, etc etc etc.
If EVERYTHING was identical, IE you hit copy and paste. In a science lab from the movies.
Yes they would have the same top speed.
It may be 125. It may be 150. That is a factor of getting to top speed, and having the HP to overcome drag.
BUT. For example lets say they both had a 6:12 rear gear, and top speed at 9K was 120. They both should have the stock HP to achieve that with no prolem. In a perfect cut and paste world they would get there at the same time too.
Gearing limited HP is something a LOT of RX-7 people run into with more heavily modified cars.
For example a TII with FD rims on it and stock tires would have a top speed of 188 in 5th gear at 7500 RPM.
225/50/16 Tires
4.10 Rear Gear
1st 3.483
2nd 2.015
3rd 1.391
4th 1.000
5th 0.719
Powerband 4K-7K
Idle 800
Redline 7500
................Idle..........Powerband........... ..Redline
1 Gear......4..............21...........36.......... ..39.............mph
2 Gear......7..............36...........63.......... ..67.............mph
3 Gear......10............52...........91........... .97.............mph
4 Gear......14............72...........126.......... 135...........mph
5 Gear......20............100.........175..........1 88...........mph
Is 188 Achievable for a TII?
Certainly.
If its modified to any extent of course.
I have a spreadsheet that has all the tranny ratios and rear gears, as well as a chart of all stock rim/tire sizes, as well as the ability to pop in different rim/tire combos, as well as Powerband and redline variables.
SO yes.
To answer the question. You "should" have very similar top end with identical part sister cars.
If you have the power to do it, and a lower rear gear to overcome parasitic drag, and drop the top end enough, you both should hit it easily.
IR two 89 FC TIIs with stock tires and rims. You MIGHT be able to reach top end. If they are bone stock, and high mileage? Ehh.
I dont think I would want to take someone's FC to that speed without changing the toe steer at the least.
Around 135-140 the stock FC in mint condition has a lot of tail waggle.
Last edited by SPiN Racing; 03-29-08 at 08:10 PM. Reason: make chart smoother.
03-29-08, 09:30 PM
#60
Stock RX-7's will not hit anywhere near their gearing top speed. You'll run out of engine before you run out of gear. The engine just won't be able to push against the air any longer.
Now, on the other hand, say you have something like 10000000000000+ hp. (Extreme example, 1000 hp is more realistic)
On the stock S5 NA gearing with a rev limit of 8800 rpm, you'll be bouncing off the rev limiter at 219.23 mph. Even though your engine can push harder than that, the engine safety mechanism won't let you spin your engine past 8800 rpm's.
So what does that mean? Ideally, a perfectly top speed geared car will have it's gears set so that the engine will stop being able to push the car forward exactly at the point where it makes peak hp.
Two conclusions:
Top speed for stock cars is determined by one of two things: electronic speed limiters set by the factory, or engine running out of power to push against the air. RX-7's fall into the latter category.
On extremely modified cars with no electronic speed limiter without gearing mods, top speed is limited by the rev limit of the car. If the car was geared perfectly, in top gear, the car would stop pushing right at peak hp rpm.
Now, on the other hand, say you have something like 10000000000000+ hp. (Extreme example, 1000 hp is more realistic)
On the stock S5 NA gearing with a rev limit of 8800 rpm, you'll be bouncing off the rev limiter at 219.23 mph. Even though your engine can push harder than that, the engine safety mechanism won't let you spin your engine past 8800 rpm's.
So what does that mean? Ideally, a perfectly top speed geared car will have it's gears set so that the engine will stop being able to push the car forward exactly at the point where it makes peak hp.
Two conclusions:
Top speed for stock cars is determined by one of two things: electronic speed limiters set by the factory, or engine running out of power to push against the air. RX-7's fall into the latter category.
On extremely modified cars with no electronic speed limiter without gearing mods, top speed is limited by the rev limit of the car. If the car was geared perfectly, in top gear, the car would stop pushing right at peak hp rpm.
04-10-08, 09:40 PM
#62
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ive done 135 4th gear 5000 rpm with mufflers and strait ram cold air next to head light no hood with factory injection 108 third gear on rev limit done 90 in second 8500 second on current set up blue jay racing four barrel intake 930cfm 6000 series predator holley blue 140 gph 9 psi 3/8 fuel system unknown engine mods not much as i can tell buried 10 grand tack twice
04-11-08, 10:23 AM
#63
ive done 135 4th gear 5000 rpm with mufflers and strait ram cold air next to head light no hood with factory injection 108 third gear on rev limit done 90 in second 8500 second on current set up blue jay racing four barrel intake 930cfm 6000 series predator holley blue 140 gph 9 psi 3/8 fuel system unknown engine mods not much as i can tell buried 10 grand tack twice
I'm pretty close to calling BS on the 10 grand, but I need to hear what you have first before I do.
04-11-08, 05:49 PM
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1988 n/a four barrel intake predator carb holley blue fuel pump and regulater dont know what was done to engine before i got it was rebuilt before i got it with efi it would only idle at 1000-1100 rpm with predator it idles at 1200-1500 no idle curcite but it dies any lower than that and it lopes is the only way to explain it have not done exaughst but it sounds like a cesna prob plane though
04-12-08, 03:21 AM
#65
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130 (so far) '83 GSL
A couple hours ago I was going 80mph then thought lets see what this has. I gunned it, letting off a little for a truck changing lanes and back to the floor again. I had 1 mile worth of road, and It was still pulling at 130
13B, Streetport, 48IDA.
A couple hours ago I was going 80mph then thought lets see what this has. I gunned it, letting off a little for a truck changing lanes and back to the floor again. I had 1 mile worth of road, and It was still pulling at 130
13B, Streetport, 48IDA.
04-13-08, 11:21 PM
#69
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"On the stock S5 NA gearing with a rev limit of 8800 rpm, you'll be bouncing off the rev limiter at 219.23 mph" -Roen
Are talking about the electronic rev limiter in the ignition? I think 219.23 at 8800 rpm is incorrect. I know the first gens gearing is shorter but i have seen my fb spin 7500 at 150mph. In fifth it ends up being about 20mph per 1000rpm or at least that what I saw. To get up to 220 you would have to spin around 11,000rpm. The gearing between a gslse and a s4 na is not that different.
Are talking about the electronic rev limiter in the ignition? I think 219.23 at 8800 rpm is incorrect. I know the first gens gearing is shorter but i have seen my fb spin 7500 at 150mph. In fifth it ends up being about 20mph per 1000rpm or at least that what I saw. To get up to 220 you would have to spin around 11,000rpm. The gearing between a gslse and a s4 na is not that different.
Last edited by Roen; 04-14-08 at 10:01 AM.
04-14-08, 10:02 AM
#70
"On the stock S5 NA gearing with a rev limit of 8800 rpm, you'll be bouncing off the rev limiter at 219.23 mph" -Roen
Are talking about the electronic rev limiter in the ignition? I think 219.23 at 8800 rpm is incorrect. I know the first gens gearing is shorter but i have seen my fb spin 7500 at 150mph. In fifth it ends up being about 20mph per 1000rpm or at least that what I saw. To get up to 220 you would have to spin around 11,000rpm. The gearing between a gslse and a s4 na is not that different.
Are talking about the electronic rev limiter in the ignition? I think 219.23 at 8800 rpm is incorrect. I know the first gens gearing is shorter but i have seen my fb spin 7500 at 150mph. In fifth it ends up being about 20mph per 1000rpm or at least that what I saw. To get up to 220 you would have to spin around 11,000rpm. The gearing between a gslse and a s4 na is not that different.
04-16-08, 09:53 AM
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anyone from toronto here?..fastest ive gone was 200 on the gardiner expressway next to the concrete divider on worn out winter tires in the summer lol. 87 fc. stock except for a koyo rad, header and catback.
