speeddemon7

Im just curious as to what I might be able to run at the track.
I currently have an intake and catback.for power mods.
the car runs well now.Since ive done a whole lot of reliability modifications.Im waiting on my profec b so that I can install a downpipe as well.I know the auto fd runs mid to low 14 sec quarter miles so what should I be seeing with the three mods that ive listed?

SlingShotRX7

15's all day long.

14's if you are lucky

13's if you real real lucky..

Sorry FD autos are DOGS

Fumanchu

Another misinformed kid.



With those mods you might be able to dip into the 13's with good launches and using the hold button.


After riding in numerous FD's with the same basic bolt-ons, I honestly think after getting up to 10mph, Auto FD's are just as fast as manual FDs. It's just the start that kills us. Also, the 2nd gear on an Auto is a killer!@

speeddemon7

yeah i agree with you.2nd gear pulls hard as hell.Even first gear once you get past 3500rpms pulls hard.I figure if a stick with 220 at the wheels runs between 13.9 to 13.5 1/4 miles a auto with about 250 at the wheels should be around the same neighborhood.

spoolage

iTrader: (2)

Not that this has anything to do with the topic. But I was on the way home and slapped a guy in an 04 cobra and it felt really good. He was with his g/f and smiled at me and made some tough guy comment to his g/f cuz I heard her laugh and look at me. From the light I ran side by side with him to about 90 then his pos american 6,000 rpm redline car just couldnt keep up any more and I waved good bye. It felt really nice to punish a car like that with a cocky guy like that. I generally never race and mind my own business but when a domestic rolls up with guys like that, I have to teach.

Mods are:

850's all around, pfc not tuned perfect yet (running rich), dp, mp,exaust, intake, .7 bars boost, and non seq twins.

I let my car cool down the rest of the way home with a big smile on my face.

Fatman0203

Thats how I normally win alot of races, the 8k red line with 4.10 gears is just killer.

turbojeff

iTrader: (30)

The best mod for an auto is to either go with the 4.10 gears out of a 5spd or spend a few more bucks on the 4.33 gears. It will really liven the car up.

Fatman0203

Yup nothing like torque multiplication! w00t!

lotta-boost

hey guys, new here , what kind of top end will 4.10 gears take away? Because I like to haul *** on the freeway!

speeddemon7

I was getting ready to ask the same question.What will the top speed of my car be if I swap to 4.33 gears in the rear?

Fatman0203

Faster than you'll want to go.

PhoenixDownVII

Well said.

It'll be just "Way too fast and you'll kill yourself at this speed" instead of "Ludicrous speed, your dead"

speeddemon7

lol.Well lets put it this way ive had the car up to 145 mph and not further than that because it was starting to freak me out.So as long as I can hit about 150 ill be fine.But I dont want my top speed to be anything less than 140 mile per hour.Some hard numbers on this would be helpfull.If anyone can provide such info.Id really appreciate it.
Someone metioned that the 4.1 or 4.3 gears multiply torque.I remember posting a similar thread once about the different pinon gears and everyone said that if the car has a certain amount of torque thats all it has.And that the different gears would only deliver the torque much quicker.So if your car makes 230 pound of torque at say 5500 rpms maybe you would see that same 230 pounds at maybe 4500 rpms instead.Am I correct on this or am I wrong?

RX7Wishing

how about you just take it to the track?

turbojeff

iTrader: (30)

It won't change the torque the engine makes. It does change the torque the wheels see.

Ever ridden a bike that has more than one gear? Why is it so hard to take off from a stop in the top gear? Shift down and you can pull a wheelie! This is the exact same principle that applies to changing the rear end gears.

speeddemon7

aha.I see now.So basically swapping to a 4.1 or 4.3 will increase accelaration and gives the car more off the line torque.Right?
will changing to 4.1 or 4.3 gears in the rear hurt the auto tranny at all? in the long run I mean.
Also the rx7 produces 217 pounds of torque in stock trim.but how much of that torque actually sees the ground?

turbojeff

iTrader: (30)

Changing the gears will not hurt the trans at all. Yes it will give you more torque off the line, basically where the auto trans cripples the car the gears will help.

I'm not sure how much torque loss there is on a auto trans, manual trans cars loose ~15% IIRC.

speeddemon7

looks like my next mod is going to be some rear end gears.Probably not a bad modification.Since it has absolutely nothing to do with the engine and boost at all.
how much do 4.10 gears run compared to the 4.33 gears.
Also with the 4.10 gears will the accelaration of the auto be the same as the manual? since they would both have the same rear end gears? the same question goes for the 4.33 gears.Or will the 4.33 gears give the auto fd better accelaration than the 5 speed?

Fatman0203

Looking at the gearing on the auto , wouldnt you want something even lower? 4.55 exist? I mean dam , its bad but 2nd gear is true from looking at the stats.

speeddemon7

what do you mean by 2nd gear is true?

Fatman0203

That its a killer gear (low)

speeddemon7

ohhh.ok.yes it is a great gear indeed.I think that most of my power comes from being in second gear using the hold feature.Of course like I said earlier.First isnt that bad either once you get past 4000k.It pulls pretty hard once you get past 3000 rpms and really hard once the second turbo kicks in.Heck even third gear is pretty nice for those top speed runs.Ive had the car all they way to 130 mph in third and could still keep going.

speeddemon7

for overall streetability as well as top speed pulls.Which gears would be best? 4.1 gears 4.3 gears 4.5 gears or 4.7 gears?

SlingShotRX7

Misinformed Kid???

Wait a minute buddy..
Lets not talk about IT SHOULD IT COULD IT WOULD.
**** on paper everythign Suppose to do this and that.

Take that AUTO FD, with the bolt ons and RUN it at the
TRACK. GUY will be LUCKY sob to run 13's.

MY MONEY is that he RUNS 15's hell maybe 16's.

Funny how all you garage queen, redlight racers
think alike.. Sound like a CIVIC forum..
Yea it does/should do this.. **** that.. RUN it
and LETS seee...

I can see it now. " well the magazine it said it run
13's stock" Hahahaha

Some of you guys sound like some fairy on a R1 or Gisser 1000, talking how fast a bike is and can't
even pop a wheelie or do a burn out..

PUT up or SHUT UP... I seen many FD's with more MODS
barely break 13's.. Me in cluded.. we do'nt make excuses. It is what it is..

Jay7 Nyc

iTrader: (3)

From what i've read and discussed with drag racers. Auto is the best option especially with Turbo cars. Keeping the boost up while shifting thru gears is not possible with manual unlike Auto. Mainly that is why alot of drag racers switch from 5speed to Auto to keep boost up and keep things simple inside the cockpit.