Do 3.55 gears really lower indicated HP?
- Thread starter Tagoo
- Start date
Took my RT out today, with this discussion about gear ratios in the back of my head. I must say, the higher ratio in my stock RT allows me to stay in gear longer which is nice around here. The somewhat longer gears, especially in first, makes driving pretty relaxing. I thought about it as I drove and not sure I would prefer to be shifting out of first quickly and generally be in third gear where now I am in second...just shifting a lot more.
Was interested in the change to 3.55, but now after driving, not so sure it fits with the way I use my car.
Good discussion though!
Was interested in the change to 3.55, but now after driving, not so sure it fits with the way I use my car.
Good discussion though!
dave6666
Enthusiast
Depends on what 20" tire you run. Stock Gen 2 is 26" OD. Lower profile 20" are less than 27" OD. My 20" PS2's are 28" OD hence the effectiveness of my 3.73 is 3.45.
Should have done 4.10
costanZo
Enthusiast
Depends on what 20" tire you run. Stock Gen 2 is 26" OD. Lower profile 20" are less than 27" OD. My 20" PS2's are 28" OD hence the effectiveness of my 3.73 is 3.45.
Should have done 4.10
We have the same setup! Or at least we used too if you altered yours at all.. You're setup originally inspired me to do the same..
iForge Classic IIs
19x11 Fronts
Tires: Michelin Pilot Sport 2, 295/30/ZR19
20x13 Rears
Tires: Michelin Pilot Sport 2, 335/30/ZR20
So now, with that said.. would you have an idea of what my stock 3.07 gears would be compared to?
dave6666
Enthusiast
My 20's with 3.07 was equivalent to 2.82:1 -->> Great on the freeway.
Just a terminology note as I am Mr. Correct lately, I often see people ask what changing tire diameters does to their gear ratio. And the answer is it does nothing to your gear ratio. You have the same gear before and after the tire change. It has an effective equivalent, which as stated mine was 2.82 with 3.07 and then 3.45 with 3.73's.
Just a terminology note as I am Mr. Correct lately, I often see people ask what changing tire diameters does to their gear ratio. And the answer is it does nothing to your gear ratio. You have the same gear before and after the tire change. It has an effective equivalent, which as stated mine was 2.82 with 3.07 and then 3.45 with 3.73's.
costanZo
Enthusiast
Alright, so my 20s with the stock 3.07 gears would be compared to 2.82... What about my 19s??
Would you say my setup of keeping my stock gears at 3.07 is a good idea? I've heard it is, and I don't mind shifting less, although more shifting can be fun, especially if your car seems faster in the process. However, I don't want to sacrifice top end power!
dave6666
Enthusiast
Does not matter the wheel size just the tire size. A 19/35 can be the same diameter as a 20/30.
the choice of gear is the choice of what you want the car to do. 'Freeway' gears like the equivalent 2.82 are great for cruising fun but not for performance fun in the 500 hp range. The equivalent 3.45 I have now is way better performance wise which if I wanted a 'sport-cruiser' I would have gotten a German car.
Shifting is really not horrible unless you consider that I could cruise the freeway in 2nd with the 2.82. Now I use 5th. RPM's come up quick when you go to kill mode so you have to be paying attention when you do the 3.55 etc.
I would not go back and would love to have the 4.10 with my 20's. Meanwhile I'm dave3.73
the choice of gear is the choice of what you want the car to do. 'Freeway' gears like the equivalent 2.82 are great for cruising fun but not for performance fun in the 500 hp range. The equivalent 3.45 I have now is way better performance wise which if I wanted a 'sport-cruiser' I would have gotten a German car.
Shifting is really not horrible unless you consider that I could cruise the freeway in 2nd with the 2.82. Now I use 5th. RPM's come up quick when you go to kill mode so you have to be paying attention when you do the 3.55 etc.
I would not go back and would love to have the 4.10 with my 20's. Meanwhile I'm dave3.73
costanZo unless your viper was converted to front-wheel-drive it dosnt matter
The fronts are just rolling along. Not connected to the driveshaft changing your "effective" gearing like the rears.
costanZo
Enthusiast
Does not matter the wheel size just the tire size. A 19/35 can be the same diameter as a 20/30.
the choice of gear is the choice of what you want the car to do. 'Freeway' gears like the equivalent 2.82 are great for cruising fun but not for performance fun in the 500 hp range. The equivalent 3.45 I have now is way better performance wise which if I wanted a 'sport-cruiser' I would have gotten a German car.
Shifting is really not horrible unless you consider that I could cruise the freeway in 2nd with the 2.82. Now I use 5th. RPM's come up quick when you go to kill mode so you have to be paying attention when you do the 3.55 etc.
I would not go back and would love to have the 4.10 with my 20's. Meanwhile I'm dave3.73
Now I was told, the higher rwhp you have the more stock 3.07 gears are beneficial. Does that only taken in affect if you're above.. lets say 700rwhp? so if you're 600rwhp or less, 3.55 are the best choice for gears? Or since I have 20s in the rear 3.73 so the equivalent would be 3.55... Sorry for all the questions, just trying to get an overall understanding.
costanZo
Enthusiast
costanZo unless your viper was converted to front-wheel-drive it dosnt matter
The fronts are just rolling along. Not connected to the driveshaft changing your "effective" gearing like the rears.
Oh alright, thanks for the info! So rears are all that matter, don't really know too much on this subject
dave6666
Enthusiast
costanZo unless your viper was converted to front-wheel-drive it dosnt matter
The fronts are just rolling along. Not connected to the driveshaft changing your "effective" gearing like the rears.
But some may have 2 sets of rear wheels. I assumed the question as such. 20's for cruisin, a set of light Sidewinder 19's for track days. In which case they are both powered wheels.
dave6666
Enthusiast
Based on the mods in your sig line you are less than 500 hp so the 3.55 would not be excessive IMO. But if you have an oversize rear tire like the 20" PS2 then you would need to do 3.73 or 4.10 to get to 3.45 to 3.55 respectively. Actually, the 4.10 would be closer to 3.73 with the PS2 20's.
Wheeeeeeeeeeeee.......!
Wheeeeeeeeeeeee.......!
costanZo
Enthusiast
Alright, well all the mods I plan on doing this summer should put me up closer to 500rwhp, or hopefully right at it. Next year I'd like to do new heads and more aggressive cam. So if in the end my rwhp would be somewhere between 500-600 would you still say 3.73 gears would be ideal? I've been told sticking with the stock gears or even go 3.33 gears would be my best choice for street/highway driving. I will most likely never track my car at all. Considering I have chrome 19 and 20 wheels anyway and would have to buy another set of like 18s or 19s for track, which I don't want to do.
dave6666
Enthusiast
If you get up to 600 hp I would say your limiting factor will be traction. Like tire sticking to the ground when you nail it if you have a 3.73. You have to figure when your 'usable' traction comes about. I can spin the tires at 70 to 80 mph with 450 at the wheels. 600 hp may mean over 100 mph before things stick.
A 3.55 however will net you at about 3.30 which some have said is the perfect ratio.
A 3.55 however will net you at about 3.30 which some have said is the perfect ratio.
costanZo
Enthusiast
Hmm.. I'll keep that in mind. I was actually told if I was gonna switch to any new gear set, the 3.33 gears would be best. So by doing 3.55 would actually make my gears comparible to 3.30 which does seem perfect. How much top end power would I lose? What if in reality I just switch to 3.33 gears? I'm not sure what that would be comparable too, but would that be good too?
So, what does everyone think of 3.33 gears for a lightly modded '98 RT. I don't like to have too short of a first gear, which is my concern with 3.55's.
Jon at Parts Rack has gear sets that run $399, but seems there are other supporting kits that are needed:
- Precalibrated speedometer kit - $179
- Normal rebuild kit - $149
- I think (if I read this correctly), internal/external service kit - $149
So, already at $876 without shipping and estimated labor or 3-5 hours (not sure about this), at $100/hour, $300-$500. Estimating this mod to run between $1,200 & $1,500.
At that price, am I going to notice enough of a difference moving from 3.07 to 3.33 to be worth it?
Thanks!
Jon at Parts Rack has gear sets that run $399, but seems there are other supporting kits that are needed:
- Precalibrated speedometer kit - $179
- Normal rebuild kit - $149
- I think (if I read this correctly), internal/external service kit - $149
So, already at $876 without shipping and estimated labor or 3-5 hours (not sure about this), at $100/hour, $300-$500. Estimating this mod to run between $1,200 & $1,500.
At that price, am I going to notice enough of a difference moving from 3.07 to 3.33 to be worth it?
Thanks!
costanZo
Enthusiast
The reason I bring it up, is because with small kids, modding the Viper is a lower priority in the house. I need to choose carefully, what I think will have the greatest impact vs the cost. This week I get my hi-flow cats installed. Then I need to decide what the next mod will be, I was actually going to have a Mopar style wing installed but decided i just didnt like it enough. So, right now seems the next upgrade will be to rr's.
Slithr
Enthusiast
First, this is very impressive. The North East guys willing to go to Mexico, for what would be illegal runs here
Second, you guys might find this thread informative, 345's bspinnin did several charts showing RPM/Speed with several gear ratios?
http://forums.viperclub.org/srt10-s...eeds-vs-rpm-warning-actual-math-included.html
This might help your decision making process along.
Phun70
VCA Venom Member
It will read slightly lower on a dyno, but will read quite a bit higher on a butt dyno.
costanZo
Enthusiast
RollerRockers are a good upgrade, I will be doing them as well. However, are you willing to spend a little more? New Headers would be a better mod then RR's. I have heard good things about the M&M Headers which are cheaper then other brands.
I'm sure they are and I know headers are a good upgrade. My intent is to keep this car relatively stock and any changes I make can be "easily" put back to original should the next buyer (if there is a next buyer) choose to do so.
I do know that the '98 was the first year that they put tube headers in the car. While probably not up to aftermarket headers, they are satisfactory for my purposes. Rockers and pushrods can be changed back and so can the exhaust.
So, for me, my choices at this point are rr's and/or rear end gear change.
But, thanks for the suggestion!
I do know that the '98 was the first year that they put tube headers in the car. While probably not up to aftermarket headers, they are satisfactory for my purposes. Rockers and pushrods can be changed back and so can the exhaust.
So, for me, my choices at this point are rr's and/or rear end gear change.
But, thanks for the suggestion!
costanZo
Enthusiast
I'm sure they are and I know headers are a good upgrade. My intent is to keep this car relatively stock and any changes I make can be "easily" put back to original should the next buyer (if there is a next buyer) choose to do so.
I do know that the '98 was the first year that they put tube headers in the car. While probably not up to aftermarket headers, they are satisfactory for my purposes. Rockers and pushrods can be changed back and so can the exhaust.
So, for me, my choices at this point are rr's and/or rear end gear change.
But, thanks for the suggestion!
Not a problem, you definitely justified your reason lol. Def don't do headers if you want to easily change the car back to stock. I did not know that was your intentions. RR's are prob your best option then considering you already upgraded your smooth tubes.
JohnnyViper
Enthusiast
after a ton of research I purchased 3:55s, its a great compromise with my SRT10 19 rears and nitto tires, I cant wait to install them later next month
costanZo
Enthusiast
Let me know how you like them... I'm still undecided if I want to do that mod... For some reason I'm attached to my stock gears
dave6666
Enthusiast
Just burn the rear end up. Stimulates the thought process of changing.
costanZo
Enthusiast
You missed some labor, you have the labor to rebuild the pumkin, then, the labor to pull and install.
Black Moon
Enthusiast
I'm just under 700 hp at the wheels and have the 355's. The jury is still out but it doesn't seem too excessive. On the other hand I haven't floored it yet the power is ridiculous with the Paxton. Without the Paxton I'd say 355-373 with stock size tires isn't too much gear at all. If I decide to go back stock I'll let you know. Last dyno tweaking this coming weekend and then we'll see what the car will do. I only put about 300-350 miles on the 355's and loved them once I adjusted to the difference. 373's would have a better choice.
Frankly gears have nothing to do with horsepower at all unless you are looking at et's. If you can handle the power the lower gear (higher number) the better, even on the street. Once you learn to control the traction you will love the gear change.
the power is ridiculous with the Paxton. Without the Paxton I'd say 355-373 with stock size tires isn't too much gear at all. If I decide to go back stock I'll let you know. Last dyno tweaking this coming weekend and then we'll see what the car will do. I only put about 300-350 miles on the 355's and loved them once I adjusted to the difference. 373's would have a better choice.Frankly gears have nothing to do with horsepower at all unless you are looking at et's. If you can handle the power the lower gear (higher number) the better, even on the street. Once you learn to control the traction you will love the gear change.
dave6666
Enthusiast
I'm just under 700 hp at the wheels and have the 355's. The jury is still out but it doesn't seem too excessive. On the other hand I haven't floored it yet
Frankly gears have nothing to do with horsepower at all unless you are looking at et's. If you can handle the power the lower gear (higher number) the better, even on the street. Once you learn to control the traction you will love the gear change.
Nicely said and similar to what I've been saying. I'd rather have more power than traction, than more traction than power.
Also, if you don't like that extra shift with 3.55's etc why did you buy a Viper? There are plenty of cars with automatics that go fast too.
