Quick question. I tried searching and the FAQ, but stupid search tool ignored the search term "s5".

This says the s5 gets 0.89g's on the skidpad, while the s4 gets 0.86g's. Both turbo and N/A.
http://www.rx7.voodoobox.net/infofaq/rx7specs.html

Is it a firmer suspension, or is it something else?

 

The tires...?

 

no answer? Oh well.

If it all depended on the tires, our cars would be pulling in excess of 1.5g's on the skidpad. Other factors in the car itself keep the tires from acheiving their best. Tires are a possibility, though it's unlikely that the s4 wouldn't have the same ones.

 

Well there are lots of variations. Tires are a valid possibility. The biggest difference could be weight. S4s tend to be on the leaner side compared to S5s. Also, suspention components differed between packages. Turbos, 86/87 Sports, 88 GTU, and S5 GTUs all had stiffer, lower springs and different dampenersthan the base models. Im not sure how big of a difference this would make on a skid pad, but the differences between the S5's VLSD and S4 clutch type LSD could made a difference numbers maybe? Just throwing possibilities out there.

 

I'm asking 'cause I hope it's the springs/shocks or tires (which I plan to replace anyway) not something like the LSD. Or if it is the LSD or some such thing then I'd like to add it to my list of future mods.

 

Not the tires, as both the '88/'89 TII came equipped with GY Eagle 205/55-16, although the '89 had a slightly different tread design.
Maybe the driver, but some of the numbers in the chart are suspect if you look closely.

Qtr. Mile Time S4/S5 TII both the same at 14.4 and the FD at 14.0
0-60 mph S4 6.8 and the S5 6.5

 

Well the S4's lighter and (I think) have stiffer suspensions.

Beats me...

 

Good point. Anybody have some good numbers for the RX-7? Or do I have to go looking? Factory claimed numbers preferred.

 

while we're at it, how about some rwhp numbers for stock s4/s5

 

Skid pad numbers are gonna be like dyno numbers, not everyone will get the same result.

If it is any consolation, grassroots motorsports was able to pull 1.04 g's by playing around with tire pressures on a stock suspension FC.

I forgot which magazine it was but they rated the FC at .91 lateral g and I have read another article at .93 g.

 

Yup, one of the biggest factors in grip level is TEST CONDITIONS. Some pavement has more grip than other pavement, shiny parking garage concrete has low grip, rough concrete has high grip. Ambient temperatures will affect the results, as will the weather (wet/dry).

With the GRM issue, I beleive that was on race tires.

 

sounds like a crap test to me, there should be varying numbers for every model not a n/a and turbo number being the same... can you really tell me a S4 SE with 4 lugs is going to grip the same as an '88 GTU? yea right... the numbers are not accurate. there is very little difference between S4 to S5 n/a vs TII, it likely was the tires and driver as well as ambient conditions at the time of the test but i reiterate the numbers should vary from model to model not lumped up.

 

Well, I was hoping for a Mazda claimed 0-60, at least.
As for Secondmessiah's question: I know actual rwhp varies from car to car even brand new, but it would be nice to know the range and/or average.

Here's a start:
http://www.rx7uknet.dircon.co.uk/rx7_fc3s_3.html
s5, I believe

 

Here's a link if you believe the musclecarclub.com:
http://www.musclecarclub.com/other-c...azda-rx7.shtml

s4:
s5:
Doesn't match the "Mazda claimed" numbers from the previous link, though. And I still don't have skidpad g's. Anybody have anything better?

 

.3 second 0-60 difference (on the second numbers) yet identical 1/4 mile?

 

Debating about skidpad numbers is a royal waste of time.
Tires is a big factor, and I doubt you would restrict yourself to only stock spec tires???
Also, upgrade suspension (parts) are a given, so are you going to restrict yourself to just stock suspension OEM pieces???


-Ted

 

Remember, the S4 is also lighter (slightly) so the lower power is not much of a factor in the 1/4, but the S5 has some extra torque to get it off the line a bit quicker than the S4. Granted this would explain it if the test conditions weren't different, which I am willing to bet they were.

I have seen my own 1/4 times fluctuate from a quite consistant time at track A, to .5 sec slower at track B due to temperature and humidity. And it wasn't just me, everyone was running slow. You all have had days like this. It is just a baseline, I know friends that have taken stock cars and beaten Car and Driver/R&T times with a fraction of the driving experience the pros have.

Something like .89 vs .86 is something we would say is in the spread.

 

Actually the S5 was only rated at a couple more torgue than the S4. The big difference was top end power and an extra 1K on the tach.

 

Good info thread, just wanted to add that I HATE that the search tool doesn't add S4 or S5 to the search, makes searching a bitch.

 

put s4* or s5*
then it should pick it up

 

lol@S4 TII running 14.4 in the quarter stock, nice to know the gearheads pumped us up though.

 

I think it's unlikely that both the 1/4 mile time and 1/4 mile speed are the same, when the 0-60 is different. If the s4 started slow and picked up speed, shouldn't it have a higher 1/4 mile speed than the s5? Anyway I think those numbers are from magazines or some such, where they drop the clutch. I'd be more interested in factory times if anyone can provide them.

 

obviously the numbers aren't accurate unless the S4 had an incline drag strip, lol. and yes the MPH would have to be different unless the S4 got a huge boost spike half way down the track. then again they list the same numbers for S5 which doesn't make sense.