Not a drag racer!

Doc

Active LVC Member
Joined
Mar 26, 2006
Messages
196
Reaction score
0
Location
Shell Wyoming
I have just instaled 20's on my MKIII and am wondering what gearing should I change to in order to get the car back to normal? I do not care about quarter mile et's but or trap speeds. I enjoy the luxury aspects of our car and the performance. I live in Wyoming where I have nothing but long stretches of highway between myself and just about anyplace I need to go, so mileage is important to me.

Thanks, Doc
 
with bigger wheels, fuel milage should be better i believe. a bigger tire will travel a longer distence with one rotation then a smaller tire. so the engine will not need to spin as fast as it used to for the same speed. if this makes any sense. acceleration will be worse, but you might savemore at the pump. then again the rims are prolly so heavy, it wont make a difference.
 
I am with you there. But in order to return to stock what should I do about my gearing? Also the rims are 8.5'' wide with 245-35's all the way around if that helps any of the math scholars out there.

Doc
 
well, im no math genious soo... heres my guess. to get it back to about normal, you could go with 3.73s, or to give it a lil more punch, you could go with the 4.10s which with those size rims wouldnt feel as peppy as if stock. but would definately be a big help over the gearing now.

i would go with the 4.10s. i have heard the 3.73s werent a huge difference over stock. just my opinion.
 
Doc said:
I have just instaled 20's on my MKIII and am wondering what gearing should I change to in order to get the car back to normal?

What's the tire diameter? Rim size doesn't mean squat.
 
Doc said:
with 245-35's all the way around

So 245/35/20 means your tire diameter is 26.752 rather than the stock diameter of 26.63. So your speedo and everything based on that (MPG, maybe ABS, etc) should be close enough that it's fine.

If you want better performance out of it, you have the same options everyone else does, gears, stall, spray, blower, whatever...
 
What will 410's do to my top speed. I run this car as fast as it can go often around here. I am more of an autobahn enthusiast than a stop light junkie. There is only one light in my town and the next closest light is 70 miles away.
 
Doc said:
What will 410's do to my top speed.

At the same engine rpms, your vehicle speed will be lower. At the same vehicle speed, your engine rpms will be higher.

For same engine rpms...

New speed = ((old speed)*(old gear ratio))/(new gear ratio)

For same vehicle speed...

New RPMs = ((old rpms)/(old gear ratio))*(new gear ratio)

You would want a chip for proper shift points and to remove the top speed limiter as well as a new speedo gear for the tranny.
 
Sorry I din't read your second post about tire size.

I would strongly caution against doing gears. Especially if you are cruising around at 80 mph. and ESPECIALLY since you said this: "I run this car as fast as it can go often around here."

In OVERDRIVE, rpms would look like this
Gear ratio....3.07....3.27....3.73....4.10
@ 80 mph: 2159....2300...2623...2884
@ 90 mph: 2459....2587...2951...3244
@110mph: 2969....3162...3607...3965
@130mph: 3509....3737...4263...4686

Of course running around in o.d. at w.o.t. is a bad thing if you like your tranny.

In 3rd, or direct gear.
Gear ratio....3.07....3.27....3.73....4.10
@110mph: 4241....4518...5153...5664
@130mph: 5013....5339...6090...6694:eek:

Running around for any length of time at anything over 3000 will get real tiring and will more than halve your engine life, IMHO.
 
Tire height is more important than rim size as stated above. You shouldn't have a noticeable difference in speedo error or MPH. 20s aren't always the heaviest either. My Marks 18s are heavier than my LSEs 20s.
 
I would think a taller wheel would sacrafice your handeling capabilites,... less wheel/more tire, should make for a better ride...
 
Less wheel and more tire would make for a better overall ride. But alas that is not what I am searching for here. I usually cruise at 100 and have over 160k on the odo; so far no problems. So if I do not do gears do you suggest: chip, exhaust, intake,? Anything else? Again not looking for trap speeds, just sustained high speeds. Also money is not a problem however I do not want or feel I need a 10k motor in my 93 MK.
 
the 245/35/20 is not going to vary by much compared to the factory 225/60/16. I would leave it alone. you shouldn't notice a difference except for the actuall ride from the smaller tire side wall. I went with a 245/45/18 on mine and it is an exact perfect match to the stock size. the 20 with the 35 series will be fine!
 
10-4. There is a slight difference in weight which leads to mass v enertia. That is what I would like to overcome. I will be calling LMS to order some parts ie: chip, intake, exhaust.

Doc
 
I've cruised for long periods of time at 95 mph, and I like where it revs at the stock gear ratio. The chip/intake/exhaust are a good idea.. You could also go to 3.27 or 3.55 gears if 3.73 is too much of a jump.

I noticed that I can really start hearing the engine at around 90 mph. It sounds nice w/ the stock exhaust, but it might get obnoxious with an aftermarket setup. Just something to consider.. Hopefully some people with other exhaust systems can chime in on the subject.
 
If you cruise at 100 regularly you might be in for some annoying exhaust drone with an aftermarket system like segxr7 said.
 
Is there not an exhaust system out there that gives performance without the racket? How about Borla?
 
MonsterMark said:
I would strongly caution against doing gears. Especially if you are cruising around at 80 mph.

I cruise 75-80 mph in 4.30s with no problem. :p

Why handicap the car for the rare occasion you get to run over 100 mph?

While you may not go as far as I did, certainly 3.73s aren't anything to fear. If you cruise 100+mph regularly, don't worry 'bout your engine life, worry 'bout your license! :eek:
 
MonsterMark said:
Sorry I din't read your second post about tire size.

I would strongly caution against doing gears. Especially if you are cruising around at 80 mph. and ESPECIALLY since you said this: "I run this car as fast as it can go often around here."

In OVERDRIVE, rpms would look like this
Gear ratio....3.07....3.27....3.73....4.10
@ 80 mph: 2159....2300...2623...2884
@ 90 mph: 2459....2587...2951...3244
@110mph: 2969....3162...3607...3965
@130mph: 3509....3737...4263...4686

Of course running around in o.d. at w.o.t. is a bad thing if you like your tranny.

In 3rd, or direct gear.
Gear ratio....3.07....3.27....3.73....4.10
@110mph: 4241....4518...5153...5664
@130mph: 5013....5339...6090...6694:eek:

Running around for any length of time at anything over 3000 will get real tiring and will more than halve your engine life, IMHO.

Is a 3.55 TL offered? What would that run according to your calculations?
 
MonsterMark said:
Of course running around in o.d. at w.o.t. is a bad thing if you like your tranny.

Why is this exactly? I could run my 4T80e at ~150mph in 4th all day if I want (on a closed track of course :shifty: ,) why does the 4R70w 4th suck?
 

Members online

No members online now.
Back
Top