No power gains?

Hi,

just found this comment and would like to discuss it. What do you think about it, is it really just all about "feeling" stronger and faster? Question was if there is a power gain by switching from 3.08 to e.g.3.73 and higher.

"We run several very good combos with 3.07 gears and higher stall converters.
I went from 3.07 to 3.73 with no gains at all in performance, in fact it only made hooking the power harder. The 3.07s are a nice gear and will help make the rear components live longer.
I know theory says with more gear, you make more power, but I have seen it time and time again that it makes NO difference at all in 1/4 mile ETs and MPHs."


What do you think?

 

you put more gear to get the rpm up fast on high horsepower engines.or to help heavy cars get moving, you probably have a more mild low rpm engine so more gear will not help you.. ideally you want to run as little gear as your engine will allow

 

Would this mean:you stay stock on the engine, you keep to your 3.08, you tune it, you go up to 3.73 and higher ? Wouldn`t a stock 350 also profit from higher gears and a more loose stall converter?

 

Gear does not effect power. It effects the average amount of power applied through the whole 1/4 mile though. If your engine is geared out of it's power range then it will apply less power to the track over the whole distance. The purpose of higher stall converters is to allow your engine to remain in or closer to it's peak power zone longer, thus increasing the average power applied across the whole track, but namely off the starting line and after gear changes.

Higher numerically gearsets target narrow ranges of rpm and lower numerically gearsets target wider ranges of rpm. So if your power curve is broad you can go to lower gears, if it's peaky and narrow you need to have higher gears to get in and stay in your power range off the line and after shifts.

 

It's basically all relevant to what the rest of your combo is. Years ago I had a 307 Nova with a mild cam, intake and headers that I shaved a whole second off of the 1/4 mile time by going from a 2.73 to a 3.42 gear, then shaved another 3 tenths by going from the 3.42 to a 3.73, but the car itself was underpowered so it needed more gear. Most big block Buicks don't need that much gear because of the tremendous torque they have, especially on the lower end. There is a member here that just ran a 12.96 at around 108mph with a 2.76 gear. Now that's impressive.

 

You have to remember that GEARS DO NOT ADD HP period. Mods to the motor exhaust intake cams compression all have HP output improvements or Reduction depending on what is done.

So Gears will enhance what your engine is putting out as the other GEntleman stated ' silverbuick' . Stall converters as stated keep the motor in the power band needed to use the most HP and torque. LOOK at a dyno sheet this is How you will pick your stall and gears so your car/truck will get the optimum power output through the complete range of the track.

For the street you might look at how you want the power to be delivered also.

GEars tailor what you put out to how you want to use the car. Street strip both etc.

As far as differences 3.08 to 3.73 shows no difference. Then you have either the converter to high on stall or your motor just does not put out as much as you think in the HP upper rpm range.

Weight of vehicle shift points tire size HP torque will all affect on what gears you want to use. Sometimes picking gears may just be a feel of the pants choice too. NOT everyone wants to have the SUPER ET slip JUST that great snappy feeling gears make you feel.

Jim
J D Race

 

If you start with a standard no mods 71 GS 350 that I happen to have, with just a few bucks to spent and you would like to spend them wisely, would you start with the engine mods, or would you start with transmisson and gear swap? I either have money for one of these ways right now, and I`m thinhking of going TH2004R and 3.73 on my STANDARD 71 GS. Am I going to feel and actually see an increase in "power"(power can`t be increased but can I "optimize" what the car has to deliver), or would you suggest building the engine and staying with the 3.08....then again our highways have no speed limit, and that is a factor that keeps me thinking about the TH2004R. Then again I would have to get the car through tech inspection, and I`m no too sure they allow a "different" automatic transmission (if they ever find out)....there are just too many things to consider that I sometimes wind up without a clue.

Jens

 

I have the perfect example of this.

I have my stock 3:08 non-posi rear in my car still. At 430 horsepower and 530 torque, with the open rear I have no traction and it hurts me timewise as I have to feather into it until I can mash the pedal.

My top end mph is almost 107 and it's still pulling like a feaking Amtrak train.

I know I could benefit from a posi and slightly higher numerical gear ratio so I could get the power to the ground more efficiently out of the hole. and probably shear off a half a second at least.

It's all about getting the power to the ground and staying in your power band all the way through. I'm not utilizing my power as efficiently as I could be because I'm not done at the top end, I can feel it. But, I also drive this car often and I don't want to make it miserable to drive either. Also, being out of money kind of makes it a moot point. :error:

 

Jens, I think you need to figure out what you want the car to do...FOR you personally.
You say it has to pass tech? Meaning??? Is this like a country emission check or something? for smog? etc.?

If all you looking for is a bit more go off the line... YES the gears will let you feel that ...But you will sacrifice the freeway driving of the car. IF you car is well balance meaning no vibration or drive line issues you should have no problem tooling around at 60-65 on the freeway for a while. It will be great for mountain terrain more climbing torque for sure.

If you have engine mods and need to go through a emission check yearly etc. You might need to watch how far you go depending on how strict they are about co etc.

Hope this helps some.

If you can burn rubber now the 3.73 gears will greatly enhance your low end even more with the neck snapping launch. Over drive will help bring back your overall feeway drivability and still give you the lowend torque your looking for. Jim

 

Thanks for your reply, Jim.
Exhausts shouldn`t be a problem concerning the fact that the car is considered a vintage vehicle and is not strictly controlled. I would like to keep it stock appearing but modify the usual things. I`ve seen a shifter from shiftworks that keeps the original look of the boat shifter and still enables you to shift your new TH2004R. Together with this I would change to a mild stall converter and 3.73 gears...it`s what I favor the most, but having second thoughts because of the beforementioned tech inspection and there way of saying: Hey, tht`s not an original 3 speed.
Second thought would be sticking to the 3.08 with a little more loose converter, modifing the engine with the ususal mods like camshaft, intake, exhaust and maybe heads.
I want it all, that`s what the problem is, a good traveller on the highway and still a little more punch off the line.

Jens

 

always start with easy stuff like gear (not to much) stall, ignition, exhaust, carb, intake,,,remember bigger is not always better..

 

Tech inspec be damned, I`ll stick with a CK-built TH2004R, a low stall(2400-2600) and a 3.73, just as planned, hope this`ll get me more off the line performance, and for highway-cruising I`ll have the 4th gear. And after that I`ll go for the engine. To keep the shifter stock appearing, do I need this kit from shiftworks? Anybody familiar with that one? I`ve read it keeps the boat shifter in P and D at the exact position the original shifter would.

Thanks for your knowledge, always a pleasure picking up a thing or two from you guys.

 

If you match a good efficient converter to a 3.08 gear, you will see little difference from a 3.73 gear.
Get a good JW converter with 3500 stall. Then go to work on the traction issue. At 107 MPH your potential with a 3.08 is 1.70's 60ft, 12.50's 1/4 mi ET. and that is a promise. Keep in touch and challenge my promise.

 

I didn't see any mention of what transmission you have right now so I'll assume it's a TH350. Something to consider in swapping to a 200-4R is the difference in 1st gear ratios alone will be beneficial to you in 'off the line' response because 1st in a TH350 is 2.52 while the 200-4R has a 2.75. So without changing rearend gears your car will now feel like is has a 3.36 rearend in 1st gear with the 200-4R trans and 3.08 rearend. Not a huge difference but noticable. Another nice benefit of the 200-4R is it will allow you to run higher numerical gears and still have good highway characteristics. I have a 200-4R and a 4.10 rear gear and in overdrive that boils down to the equivalency of a 2.75 final ratio in overdrive and lots of snap off the line. It's basically the principle of making the leverage work for you, which will make even a stock engine feel like it has a lot more power.

 

Thanks for your thoughts. Concerening Gary`s idea, I think 3500 stall is too high for me because I want to ride the car mostly on the street, and around here a traffic jam and stop an go traffic is a common sight, but it sure sounds interesting that you can reach these numbers with a 3500 stall converter.
Bill, that`s why I think the TH2004R is the best for my car, but as mentioned before, I`m a little scared taking the car to tech inspec. Do you know about the shiftworks shifter for the boat-style ?

shifterhttp://www.shiftworks.com/buick.htm

Making it look stock should be enough for those guys around here.

 

Some of the guys on v8buick say their 3500-3700 stall feels like a stocker. Your can get one for $475 from JW or pay $900 from Coan. New technology is making dreams come true.
For traction, make sure you have skylark springs such as 5230 Moogs on front and 6321 Moogs on the rear. TREMENDOUS difference in traction. Then go to no-hops or UMI lower arm brackets and/or HR rear anti-sway bar. Keep it simple.

 

I kinda forgot your not trying to make a race car out of your car.
However, It is fun to have spunk when you hit the trottle.
The 200-4r is a great choice because it has a 2.75 low gear (and overdrive). a 2.75 low X 3.08 rear = 8.47 starting gear ratio (200-4r trans).
a 2.50 low X 3.42 rear = 8.55 starting gear ratio (TH350 trans).

The overdrive is better suited to a 3.42 gear. 2.75 low X 3.42 gear = 9.405 starting gear ratio. That will have some SPUNK.