Throttle Body

BurningRubber said:

With 4.10's I've hit 113 in the 1/4 on a 26" drag radial. Was turning right around 6100 according to the tach.

I also have seen 25mpg highway with 3.27's as well as 4.10's. This will always be a never ending debate, but any N/A 2v needs a steep gear.

Click to expand...

6100 on a 26" tire gets right at 115, give or take. Considering the inaccuracies of the stock tach, that sounds just right.

And yes, taller tires start making big differences on top speeds. 26" slick gives an extra 1.5 mph over 25.66" tires (stock size), and 28" tires give over 10 mph more than stock tires. Somehow, I doubt the OP will ever be running slicks.

And also, just a little extra RPM at that speed makes a big difference, too. Every 100 rpm over 6000 gives an extra 2ish mph. But it is of my personal opinion that going over 6000 on a stock bottom end is only asking for trouble. Especially repeated occasions. Remember that this is happening right at the end of a run, and the motor temps/strain is already at its greatest.


OK, I've tried to avoid it, but I'll go ahead and spill my opinion on the gears. IT IS OF MY OPINION that 4.10s are too much for a street driven 5-speed. A car that sees the track regularly with good tires? Or one where the owner wants to squeeze every last second and mph out of it? Yes, the more gear the better.

BUT, for a car that is going to be driven on the street 99% of the time? No. It is too much. While fixing my car, I am currently driving my granddad's 94 5.0, 5 speed, mild cam, ported stock heads, intake, full exhaust, and 4.10s. It might make 270 rwhp, roughly the same amount a full bolt-on PI 4.6 would make. It has good tires on it, 295/35-17 size on the back. On the street, 1st gear is 100% useless. Go WOT at any point, and it goes sideways. 2nd gear is like that sometimes, depends on if you break them lose on the 1-2 shift or not. I'd put money on it that ON THE STREET, the SAME car, with 3.73s, would beat it. Traction is just so much harder to come by with the 4.10s. The 4.10s are really only useful if you have a sticky tire (read: drag radial or slick) at the track.

Even then, the advantage isn't that terrible great. Using the racing calculator I made (which I have determined is relatively accurate) on a mostly stock 2 valve 4.6, the difference between 3.73s and 4.10s in the 1/4 is LESS than 1 mph. The loss of traction on the street just isn't worth fractions of a mph at the track.

So, in conclusion, if the car is a street car that will not or rarely will see the track, IN MY OPINION: 3.73s for a 5-speed, 4.10s for an auto. Take it for what it's worth.

ktaylOR2012 said:

hels alot thanks ya mine is my dd till i get the money for another car once im out of school ill probly put alot more money in my stang but i think for now im going to go with 3.73 then cold air exhaust and other bolt ons then new rims and then if i feel like i need more then ill go put the 4.10s in

Click to expand...

I think that's a good plan that will leave you very happy.

I don't feel like typing out a long counter argument on my phone.

OP - go put 3.73's in your. When you realize you should have went with 4.10's, just go ahead and send Nightfire and myself a PM saying "I should have listened to you guys and went 4.10's".

Stumbaugh said:

I don't feel like typing out a long counter argument on my phone.

OP - go put 3.73's in your. When you realize you should have went with 4.10's, just go ahead and send Nightfire and myself a PM saying "I should have listened to you guys and went 4.10's".

Click to expand...

If you get chance, I would like to hear a different perspective. I'm not at all trying to pretend that I know everything about it, but my experience with 4.10s in a 5 speed (and everyone else's that I personally know with a similar setup) is that it's not a street friendly combo. It's GREAT for the track, but not so much on the street. It's like having a car that makes 800 horsepower that won't do ANYTHING on the street until 80 mph, and then saying, "Oh, I need more power!" What good is all the gear/torque in the world if you can't put it down?

I mean, I just went and took a friend for a ride in the 5.0 I'm driving right now; smashed it in 1st, dang near instantaneous redlined from the wheel spin; yanked 2nd, and smoked through the tires in that gear as well; grabbed 3rd where it finally hooked, and it was only turning 2500 RPM and WAY out of it's power band. If that scenario happened at a stoplight next a V6 Accord or Camry, it would have smoked me.

ktaylOR2012 said:

hels alot thanks ya mine is my dd till i get the money for another car once im out of school ill probly put alot more money in my stang but i think for now im going to go with 3.73 then cold air exhaust and other bolt ons then new rims and then if i feel like i need more then ill go put the 4.10s in

Click to expand...

Another one that feared the gear. Best of luck to you.

BTW, I just find it odd that you say that money is an influential factor in your modding decisions but then say that you will be swapping gears multiple times? You do know that gear swaps will run you $500+ right (on average)?

I just want to throw one more thing in. I took a class last semester with a guy that had an 03 GT and it had basically the same mods as mine (at the time) but he had 3.73's. I let him drive my car for the sole sake of comparing the gears. He said my car was a hell of a lot quicker than his, and he drove it like he stole it.

That car is not spinning that bad because of 4.10 gears. I can promise you that. Sounds like the car has absolutely 0 suspension work. My car hooks just fine. I put a friends street tires on it the other day and it hooked just fine. You are acting like the difference in a 3.73 and 4.10 is night and day. It's not. From a 1st gear roll, you would not notice a difference in the hit of the car when you punch it with 3.73's or 4.10's.

I also have a buddy who's car has the same mod's as mine, except he has a 75mm TB and 3.73's, and mine has a 78mm TB and 4.10's. Dare to ask whose car is faster? Or whose car hooks up better?

Care to share what suspension mod's are on the 4.10 car your driving?

I have owned plenty of mustangs in my time. All of them had aftermarket gears. All of my stuff gets drove a lot, rain, sleet, and snow, doesn't matter. I have owned 1 other car that had 4.10's in it and that car and my current one are the 2 I have been the most happy with.

My experience with it was this. 3.73's made me either want 3.55's or 4.10's. It just wasn't low geared enough for dig racing, but to low geared for roll racing (40mph +).

But just like what you said Will, this is just my experience. It's all strictly a matter of opinion. My post about the PM was strictly a joke.

4:10 gear all the way. The highest I would go is 3:90s. I have 4:30s in my car and enjoy the piss out of them.

First you said you daily drive your stang! Second you also said you car spins in the rain with stock gears! If you want a "safe" DD, purchase a good set of tires FIRST. Tires that can handle the gear and also do decent in the rain.

Oh god. Its a "which gears" thread now.

4.10s NA, 3.73 Blown

ive had 4.10's and 3.73's. each has their perks... i will say this, when i went from 3.27 to 4.10 n/a, my gas mileage went from 28 mpg highway to around 21 mpg highway. when i put the kenne bell on my car the 4.10's were a BLAST to drive with, but very impractical. 1st and 2nd were worthless, and if there was any dew on the road, 4th was scary, imagine punching it to pass a car in 4th and going completely sideways... it can be a bit nerve racking.... i put 3.73's in it last winter, i am happy with them with the car being blown... i would highly recommend 4.10's if your staying n/a. I would even venture to say that if i were to have stayed n/a i would have rather had 4.30's. dont fear the gear. if i could do it all over again, i would have kept the 4.10's in my car and spent the money on control arms and drag radials instead of buying 3.73's. granted, i would be flirting with disaster, i was bouncing off the rev limiter on the 1/4 at 110 with 4.10's. i traded safety for fun. i picked up 2 mph and 1/10th by switching to 3.73's, however, if i would have just bumped up my rev limiter to say 6500 i would have trapped a higher mph and better time with the 4.10's. for what its worth, i will say that you will not be disappointed with either gear over stock. however, i am willing to bet that if you go 4.10's the fun factor will increase. just remember, opinions are like a-holes, everyone has one... (just dont fear the gear)

I forgot I posted in this thread a while back...fiveoho ill post those sheets for you when I get a chance...either be late tonight or tomorrow afternoon

Nightfire said:

Im so tired of hearing the "Im going to get 3.73's because Im concerned about gas mileage". The difference between 4.10's and 3.73's are not much. Just go with the 4.10's.

I dd my 4.10 car and get 20-22mpg's.

Click to expand...

Driving from FL to TX I clocked at about 25-26mpg with 3.73s and mods in sig.

Found this crappy pic from the road trip.



2270 RPMs @ 75mph.

I prefer to stay as close to 2k RPMs on the highway, and at the time I was doing like 80% highway driving, so I went with 3.73s. I already have traction issues with 270rwhp and 315s out back, so no need for 4.10s.

ok i dont know if my computer is being a piece of chit or if photobucket is broke but for some reason photobucket wont pull up the upload bar on the screen. I guess ill upload the pics of my sheet from work but ill put the info down for now.

1st ever dyno pull. Only mods, mac o/r h and flomaster weld-ins:
temperature - 61.7* in December
231.9 HP 272.5 TQ

3rd pull ever. BBK CAI, BBK 75mm TB, C&L Plenum, Mac o/r H, Flowmaster weld-ins:
temperature - 84.1* in May
247.6 HP 283.2TQ

4th pull ever. Same mods:
temperature - 84.6* Same day as run 3:
245.8 HP 281.3 TQ

So with the CAI, TB, And Plenum i gained 16rwhp (though it was 17 as stated a few pages back) and 10.7rwtq. What mods are making the most power from that combo i cant tell you. All i know is i gained power from those 3 items.

once my computer stops effing with my the dyno sheet will be posted

take it how you want and dont flame me or anything, and im not trying to start some big arguement, im just showing that there was a performance gain on my car from these items

Sonic04GT said:

I already have traction issues with 270rwhp and 315s out back, so no need for 4.10s.

Click to expand...

Coulda summed up my entire gears argument with this one sentence.

And, dang I wish I was only running 2270 rpm at 75 mph with 3.73s. I'm turning that much with stock 3.27s, and would be at almost 2600 with 3.73s. Really wish I had a .62 OD ratio, as about 75% of my driving is on the highway. I want 3.73s at some point in the future, but don't want to trade any mileage for them.