Street Gear Poll

Which street gear?


  • Total voters
    443
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What about 3.23s? Awesome for the freeway or general driving too.

That's what I run with my 340 4 speed and am flirting with 12s in the quarter mile
 
I have the same build going but I was leaning towards the 3.23's. Have you ran both?
3.23's were the all around gear. I like this ratio better then the 3.55's that were installed in rear when I got the 8 3/4. Warmed over 273 with 302 heads. 904. Charger pistons, original 273 4bbl engine. :burnout:MT
 
With 275/60's, I'd go with the 3.55s over the 3.23s. That's a good size tire. Especially with a 318. It'll appreciate the shorter gear.
I agree with this. Im running 14 inch tires. 24 1/2 tall rubber..:burnout:MT
 
I'm doing a 318 4 barrel with a 727 and 275/60r15.

318 is gonna have a 474 lift cam and some head work done. Bigger valves. Ported. Not sure if I have to bore over yet.
 
I figure most street engines should be build around the gear choice. When your deciding the amount of driviblity your willing to lose for performance, gears being one of the main considerations. When it comes to race engines as long there's no gear rule you can build the engine and gear it to work same with street engine but most want to stay in the 3??:1 range. Really most cars are way under gear especially low performance cars. Take a car that makes peak power at 4500 rpm and could do the quarter mile at 80 mph not a real rocket ship but would need 4.56:1 plus gears to hit it's powerband.
 
273
I hear what you are saying, but I don't agree with the way you are using the word, powerband.But I have no better wording either.
I think what you are getting at, is for a best mph, the car needs to trap at an rpm that has wrung the most out of the engine that it has to give, in as many gears as are in the tranny.That works well for an automatic, but a street car with a stick, takes time to shift,during which no power is being transmitted. There may be a benefit to limiting the number of shifts to 3 in an 80 mph stick-car. In a 110mph car 4 would probably be better.I'm just throwing numbers out there. In any case, you are always gonna want to gear it to trap well,in top gear.
--But I'm of the persuasion that the engine should be built with the tranny gear-spreads in mind. If you have a 4-gear tranny with tight ratios, you can make use of an engine with a narrow powerband. If you have a wide-ratio 3-gear tranny that really pulls the Rs down,she will need a wider powerband ,so it can pull itself back up out of the basement.
--My current combo was built for the A833 O/D box which requires a very wide powerband, cuz the splits leave the engine in the basement. The ratios are 3.09-1.67-1.00-.71 or .73. The splits are 54% and 60%. That means when I outshift at 7000, the Rs fall to 3780 and 4200. So that tranny needs a 3220/2800 rpm powerband. That's huge.
I realized right away that was no fun. So I slid a 4spd in there with a GearVendors behind it, which can be used as a splitter.The useable gear ratios with this combo are; 3.09(1st)-2.41(split)-1.92(2nd)-1.50(split)/1.39(3rd)-1.00(4th)-.78(O/D) The splits with this tranny are 78%,80%,78% for the first 4 ratios .Now I only need to outshift at 6400, to drop in at 5000. This reduces my powerband requirement to 1400rpm. This puts down a lot more average horsepower during the run. So now I don't need that 3000rpm powerband anymore.
In theory I could tighten up the LDA from it's current 110 to something like 104, and get more specific horsepower out of the combo, while giving up the tractor-like midrange and also giving up some off-the-line giddy-up. But with the 3.09 x 3.55 = 10.97 starter gear, getting off the line is not a problem.
And since the car has already gone 93 mph(1/8th) with this combo, I am certain it would go faster. But 93@6400 requires a trap gear combo of 5.42. Since I will be in 2nd over, which is 1.5 ratio, to trap well I would need 3.61s. Hence why I run 3.55s. They put me on the line at 6150, which is probably where it needs to be.
--So getting back to your example, with a 4500 rpm shift point, 80 mph trap, and a 904, and 4.56s.This tranny has ratios of 2.45-1.45-1.00, which gives a starter gear of 11.17, and equates to drops of 59% and 69%. This means that the Rs will drop to something like (0%TC slip),2655 and 3105.And that spits out a powerband requirement of 1845/1400. But if it was an A833 with ratios of 2.66-1.92-1.39-1.0; The starter gear would be 12.13, and the drops would be 72%,72%,72%; and the Rs would fall to 3240, making the powerband requirement just 1260.It doesn't sound like much, but the math says it's nearly 1/3 less Rs.
I think it should be readily apparent which tranny will pull a better mph.
The rear gear, in drag-racing, only helps you two times; through the traps, maximizing your MPH, and off the line. The rest of the time it gets lost in the total reduction number of; rear gear x tranny gear x splitter gear (if you have one), x engine torque, and becomes just part of the equation, getting you from here to there.
 
AJ/FormS that also huge part most don't figure out is the Trans gearing. To me from the Air cleaner to the rear tires everything should be matched to work together.
 
I run a 4.30 gear in my car with a 4 speed and 28" tires. I had a 3.73 in it originally and I would never go back to it. Overall I think the best OVERALL gear for the average guy is 3.91-4.10.
 
440
your combo is trapping around 6969 mathematically speaking.For you it may be optimum.To say that 3.91 to 4.1 is optimum for the average guy is kinda misleading, I think. Unless you know exactly What his W/P ratio is and his trap speed, and his tranny set-up is etc. To throw a number out there for the average guy, you kinda need to define the average guy.
For instance a guy with a 3spd trapping in 3rd will need a different rear than a guy trapping in 4th with a 5 spd.
Or a guy with 350 hp will want a different gear than a guy with 400 or 450.
Or a guy like me ..... who runs 3.55s to 93 in the 1/8th, on 400to 430hp, because I have a 3.09low gear. Now the 3.09 x 3.55 =10.97 starter gear, and 10.97 /the regular 4spd low of 2.66 = 4.12 starter gear. So same car uses two vastly different rears with two different low gears.
Mr Average could stick a 3.91/4.1 in there , go out and make a few runs, get an mph number, and find out he missed the mark a lil, and have to swap those out.
He could have done that with 3.55s or 3.23s or anything and saved himself the cost of at least 1 gearset.
Am I making sense?
 
I have a 440 in my GTS with a sure grip 3:55 and P225/70R-15 rear tires. This set up does not burn up the tires on a hard start and helps with better gas mileage.
 
440
your combo is trapping around 6969 mathematically speaking.For you it may be optimum.To say that 3.91 to 4.1 is optimum for the average guy is kinda misleading, I think. Unless you know exactly What his W/P ratio is and his trap speed, and his tranny set-up is etc. To throw a number out there for the average guy, you kinda need to define the average guy.
For instance a guy with a 3spd trapping in 3rd will need a different rear than a guy trapping in 4th with a 5 spd.
Or a guy with 350 hp will want a different gear than a guy with 400 or 450.
Or a guy like me ..... who runs 3.55s to 93 in the 1/8th, on 400to 430hp, because I have a 3.09low gear. Now the 3.09 x 3.55 =10.97, and 10.97 /the regular 4spd low of 2.66 = 4.12. So same car uses two vastly different rears with two different low gears.
Mr Average could stick a 3.91/4.1 in there , go out and make a few runs, get an mph number, and find out he missed the mark a lil, and have to swap those out.
He could have done that with 3.55s or 3.23s or anything and saved himself the cost of at least 1 gearset.
Am I making sense?

I never said what gear would be optimum for him, I just said that for the average guy looking for the best overall gear, you can't go wrong with 3.91-4.10.
 
I have ran a street car with 4:88s & 325/60/15 tires & whole cow is right
 
I have a 4.89 chunk right here in storage, and a spare C&P set on the shelf. I'll probably never use them again. I recently sold my 4.30 chunk.I had those for many years. The 5.13s, and the 3.91s broke and are history. I traded my 4.10s for a set of 3.55s;Got nothing else left now,but the 3.55s and down. Never had 4.56s
 
Just for "whatevers"- calculated my tire diameter/gear combo and came up with this:

my 3.55's SG w/25" tire diameter (with 14" rims) equals 3.55 (DUH)

my 3.55's w/26" tire diameter would become like I installed 3.41's

my 3.55's w/27" tire diameter would become like I installed 3.27's

my 3.55's w/28" tire diameter would become like I installed 3.16's

Thinking about 15" wheels with a tire diameter of 27" for a more "3.23 like" ratio.

Cheaper and easier than putting a 3.23 gear set in my 8.25

'67 Dart GT w/383
 
And the 27 incher;
Will have a bigger better footprint with a taller more flexible sidewall, which
may help the 383 hook;if you can't go wide, go tall
And can run on less tire pressure, for a smoother ride
Allow you to run flatter rear springs for corner control
May give you the popular front down attitude, which, on a streeter,helps traction nothing.

275/60-15 is about 27.99
275/50-15 ...........25.83
255/60-15............27.05!!!
 
Shoot so going off that math my 2.94s with 28" tires are more like 2.6x?

I need 3.55's, stat!
 
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