I found this cool chart at Neons.org shows you everything on what certain gear ratios and tire combos do.



(All Measurements are based off of 205/55/15 tires) MaxMph at max Engine speed Specs below (All specs are based off the fact the cars had enough power to do these speeds based on the stock gear ratios)

a SOHC 5 speed car (3.55 MTX) 180mph at 6480 Rpm in 5th Gear.

DOHC 5 speed MTX (3.94) 5th gear:118mph 5304 Rpm 145mph at 6518 Rpm

a SOHC ATX (2.89 ATX) at 6106 Rpm will do 150mph in 3rd gear (Drive). At 118mph it is doing 4803 Rpm

the DOHC ATX (3.63) at 150mph will run 7669Rpm 118mph 6033Rpm


**DISCLAIMER** (if you own a DOHC Engine please do not take this to heart or think you have a bad engine because this is for fun and its also true! its from the .org so of course its true!) I didn't intend this to be a DOHC bash but I noticed that there was something weird in the way the gear ratios x Rpm vs the sohc didn't add up.

Do you guys see the trend in the chart above? Lower Gears for the DOHC across the board,This is why You guys believe the DOHC has more power than the SOHC.The only way you DOHCguys get to use the500 Rpm Advantage youall brag about having over us SOHC Guys is to use a SOHC transmission, otherwise yer pretty much equal.

Lets see a SOHC with a R/T 5 speed go up against a DOHC with an R/T 5 speed betcha the SOHC wipes him in the Quarter Mile. These Gear ratios prove that you guys should be swappingDOHC Trannys into your SOHC carsinstead ofDOHC Motors. I bet nobodys ever tried this combo and if they did they fear ridicule so they wont post their results because alot ofthe DOHC Guys are so pompous and arrogant.

I knew the DOHC wasn't that much better than the SOHC and Ifinally found the reason. I still defend that the DOHC is a good motor but it obviously isn't as complete of a motor in the powerband as a SOHC is. 2+ for the SOHC Guys!

From the 2-3 Wheel Horse Power Dyno Difference to the low gears to help the Low End lacking DOHC it seems that once and for all a SOHC has proved to be the better motor. The SOHC is the victim of Circumstance, it could have had the DOHC glory and MOREbut engineers at chrysler decided this motor should run taller gears for economy just because it had the power to run those gears and theDOHC lacked that all around power so it needed the shorter gears.

I really wish people would stop recomending the DOHC over the SOHC, build what you got in your car! thats what I recomend! weather its SOHC or DOHC build the fkr and be happy! There are 2 Neons that do 8 second Quarter miles and 1 uses a DOHC and the other recentlyis a SOHC.


This isn't just me flaming about the DOHC Engine again its actual proof that the DOHC is not the fabled Engine from theFast And The Furious Teenage tuners talk about. Its quite frankly exagerated and embellished to the point that people don't realise the bull**** they feed people and the real stuff they believe.

I wont stop exposing the DOHC's flaws until somebody admits its not worth it to swap a SOHC for a DOHC stock for stock.Who would have thought that all along you would get better performance from the DOHC trannys than the actual DOHC itself!

 

this is what I learned from taking a transmission and drivetrain course the higher numerically ratio the quicker the accerlation but the top end is lower the lower numerically ratio the higher the top end but accerlation is slower for example since I am old school muscle car my friend had a 68GTO with factory 4.88 rear gears drag racing stop light to stop light he would smoke everybody all the time as he car would top out at around 100mph but would reach it quicker than hell but when he took it the drag strip he would loose most of the time as due to the distance it would allow someone else time to accerlateto 120 or so and pass him at the last second so in reality it all depends on what kind of driving and or racing you do, However if you were to put the same tranny in a DOHC and then put that same tranny in a SOHC I believe the DOHC would beat it based on RPM and torque curve
personally I would rather put a SOHC tranny in DOHC to get better RPM range while driving on the highway as at 70mph I think 3600rpm is a little too high and buy using a lower gear ratio it would bring the rpms down and increase highway milage

 

That's why I changed my ATX transfer gears, 70MPH = 3200 RPM, and +2 MPG.

 

Not really the SOHC would be allready taking off sooner especially with the quicker DOHC gears and its fatter power band. This is the same prinicipal why DOHC ATX cars can't fight their way out of a wet paper bag against a SOHC ATX. Its because even with the lower gears they suck on the low end. The DOHC has more "peak power" by 2 wheel horsepowerbut lacks a fully functional powerband under that 1,000 Rpm sweet spot where it makes peak power.

On my DOHC 5 Speed Neon if it wasn't for the fact I could drop the clutch at 5,000 Rpm and that the gears are 3.54 for first gear ratio the DOHC would be pretty disapointing. I'm going to swap a SOHC headon it in summer and see for myself if I am correct, the water pump is leaking on it now and so I need to change that **** anyway.

The thing has nothin' under 4,500 Rpm even with the nice gears.

 

i have only been a neon owner for about 3 months I based my thoughts on past experience that usually motors with identical displacement usually the DOHC motors have a better midrange and top end but when but the bottom end is typically similar but that isn't always the case

 

The Neon DOHC and SOHC are a pretty good match against eachother in a race, both use simular shaped 4 valve per cylinderhead.

When comparing simular gear ratiosThe SOHC always takes the DOHC on the bottum and mid range but on the top end the DOHC makes up some of its lost ground. After I found this out about the DOHC having shorter gears I did some research and actually have found people who have done the DOHC tranny swapin the SOHC with Amazing results!

The SOHC has always been looked at as an Economy Engine when it really madealmost the exact same peakpower to the DOHC Engine. The DOHC has always been regaurded as the performance option and the only thing that really makes the DOHC have more snap than the SOHC is itsconsiderably lower gears.

What you see here is:

Economy: Tall gears (SOHC always got these which is whypeople think its slow, not once ever did the SOHC get the DOHC snappier transmissions)

Performance: Shorter Gears

I would like to see how many people favor the DOHC if both Engineswere using the DOHC's transmissions. I was right all along about the SOHC being underrated, these motors are within 2-3 hp on the chassisdyno why the fk would chrysler promote the DOHC as more powerfull? the Answer is because they needed a 2ndengine option for marketing purposes. I think these gears are the smoking gun I've been trying to prove existed for years.

 

Are the gear ratios in the transmission different or just the final drive ratio for the diff unit?

 

SOHC ATX Final Drive Gear:2.89 1st Gear: 2.692nd Gear:1.55 3rd Gear: 1.00

DOHC ATX FInal Drive Gear: 3.63 1st gear: 2.69 2nd Gear: 1.55 3rd gear: 1.00

As you can see the DOHC Transmission would make your SOHC more snappy than a stock SOHC Transmission.

SOHC MTX Final Drive Gear: 3.55 1st Gear: 3.54 2nd gear: 2.12 3rd Gear: 1.36 4th gear: 1.03 5th Gear: .72

DOHC MTX Final Drive Gear: 3.94 1st gear: 3.54 2nd gear: 2.12 3rd Gear: 1.36 4th Gear: 1.03 5th Gear: .81 or .72

(DOHC ACR's and R/T'shad the .81 5th gear, regular DOHC MTX's had the .72)

Again Take note that the Final Drive Gear is lower across the board for the DOHC for more off the line acceleration.

When we are talking final drive gear we mean the differential Gear not 5th gear.(I know you know this Mike but for people who don't I put that in )

This is one reason why SOHC's are noted for being average on take off. A DOHC transmission would make things alot easier! not only off the line but everywhere else!.

I bet this is the reason the DOHC has such highend cuz it can wind out those shorter gears a little bit faster than the SOHC can on the top end.

I respect the DOHC because its mopar and I embrace them but I think the fact that the DOHC has ashorter final drive gear is great news because us SOHC guys can use a cheap performance upgrade for those long drawn out SOHC gears. I almost wish I would have known this before I did my transmission last October.

 

can youget a gen 1 dohc tranny and put it in a gen 2 (2000) ??

 

atx NO
mtx yes just change the bellhousing