4.56's slowed down my Coyote - advice, please

[Five Oh Brian]

The 4.56's will make everything louder, just due to the higher rpms' your turning but if the gears are set up correctly they shouldn't be making any noise. If yours are making noise then they aren't set up correctly.


Earl

My factory gears could already be heard as my aftermarket LCA's have spherical steel bushings instead of poly or rubber, so the steeper gears are just amplifying the noise that much more. I will talk to the tech that installed them as this is the 4th car he's done gears on for me. Maybe he can minimize the noise a bit. It's only on decel - accel has zero noise.

 

[Five Oh Brian]

Here's 2 comparisons of your splits. Make sure I got the numbers right, those pictures weren't very good. I took the 12.15 out of the 2nd comparison since it was more of an outlier. Red=worst, Green=best. Lots of green in those older runs. You've improved the car to 60, but looks like you've killed it after that. 60-1320 was much quicker before. DA shows as worse on your previous runs, something like 242' now vs. 718' then, so there's a little more difference than the numbers show. Take the gear out.

Wow, thanks for taking the time to put that table together. Very enlightening!

While the 3.73's did have the lowest ET and best trap speed, it was incredibly difficult to repeat. The launch was so hard with the 3.73's, that I often had passes in the high 12's or even into the 13's when it bogged so often. It was incredibly frustrating to have a car that could run 12.15 one time that went 13's plenty of other times. The 4.56's cured the launch so that it is simple to repeat over and over again. Every single launch (sixty foot) with the 4.56's has been better than the 3.73's ever were, and it is super simple and repeatable. Every run with the 4.56's was in the mid 12's as a result. So, the stress is gone about consistency in that respect, so I'm very happy with the 4.56's. Just need to find a way to improve the run after the 330' mark.

 

[Five Oh Brian]

Take the gear out.

I've given that plenty of thought in the past couple days and just don't know if I can go back to the 3.73's for a variety of reasons. It seems like every time I solve one problem (my launch, in this case) another problem crops up (worse ET/MPH). I love the launch and daily drivability of the 4.56's way too much right now to undo this mod.

Better tuning is the next step. Beyond that, simple breathing improvements would be next (exhaust and airbox). After that, maybe I can whine enough to talk the wife into supercharging this car (my '07 GT was supercharged, but only after a couple years of begging - LOL).

 

[BAKnBLK2010]

I don't see how you are bogging on the launch with 3.73 gears unless you are leaving off idle. There are plenty of N/A 5.0 6M cars with 3.73 gears cutting 1.50 sixty foot times and running deep into the 11's......

 

[skwerl]

Perhaps 4.10 gears might make your launches manageable without killing your ET as much?

 

[stratman]

Can you even use 1st gear with the 4.56s?

 

[kdanner]

I've given that plenty of thought in the past couple days and just don't know if I can go back to the 3.73's for a variety of reasons. It seems like every time I solve one problem (my launch, in this case) another problem crops up (worse ET/MPH). I love the launch and daily drivability of the 4.56's way too much right now to undo this mod.

I understand completely. My automatic with the 4.30 gear "felt" way better than it does with a 3.31. It's kind of boring without all that gear. Although the 4.30 was quicker at the track down low, it makes up for it downtrack now. The plus is it hooks all the time now. Best thing you can do for traction is put an anti roll bar on.

 

[BlackDragon]

What do you have for suspension?

 

[Five Oh Brian]

I don't see how you are bogging on the launch with 3.73 gears unless you are leaving off idle. There are plenty of N/A 5.0 6M cars with 3.73 gears cutting 1.50 sixty foot times and running deep into the 11's......

I don't know why I was bogging with the 3.73's either. I've been drag racing for 30 years - mostly with stick shift cars, so I'm certainly not new to the sport. I've never had a car do this to me. Stock tune and SCT tunes (87 octane and 91 octane) all did it. I could leave at idle and not bog. Any rpm's and the sticky tires would kill the fun. Running them pumped up to 30+ psi and not warming them up at all helped, but then I'd have tirespin killing the consistency.

A friend that races with me quite often was watching my launches a few weeks ago and suggested steeper gears to get the car off the line easier. I don't know why I couldn't launch with the 3.73's, but my car simply didn't like them and the 4.56's cured that part of my passes.

Ultimately, I think it'll be easier to fix my runs from 60' to 1320' with the 4.56's than to go back to the 3.73's to figure out the launch. Considering that most races are decided in the first 60', I'd rather not have that be the problem with my passes.

 

[skwerl]

Are you completely turning off the traction control? I've heard you need to apply the brake and hold the TC button for 20 seconds to completely turn it off.

 

[Five Oh Brian]

Perhaps 4.10 gears might make your launches manageable without killing your ET as much?

The 4.10's would likely help the launch. I'd still have to shift into 5th gear with 4.10's, though, and it would be too close to the traps, IMO. I think the extra shift is some of my issue. I'm not willing to spin the engine past 7200 rpm's, so I can't simply spin it to the moon in 4th to avoid the shift into 5th.

 

[Five Oh Brian]

Can you even use 1st gear with the 4.56s?

Absolutely! At the track, it works awesome and I even have time to grab 2nd gear without hitting the rev limiter. On the street, I use 1st just to start on uphill grades. Otherwise, I start in 2nd gear around town. I used to do the same with my '03 Mach 1 which had 4.30 gears.

 

[Five Oh Brian]

I understand completely. My automatic with the 4.30 gear "felt" way better than it does with a 3.31. It's kind of boring without all that gear. Although the 4.30 was quicker at the track down low, it makes up for it downtrack now. The plus is it hooks all the time now. Best thing you can do for traction is put an anti roll bar on.

I've always been a 'gear junkie.' Makes daily drivers so entertaining even if it doesn't always make the car quicker at the track. You are so right that regular gearing is boring!

 

[Five Oh Brian]

What do you have for suspension?

Stock suspension except for Maximum Motorsports dual adjustable LCA's that cured the bad wheel hop that came from the factory. And, 275/50/17 M&H Drag Radials at 25 psi that hook awesome with just a quick burnout to clean them off.

 

[Five Oh Brian]

Are you completely turning off the traction control? I've heard you need to apply the brake and hold the TC button for 20 seconds to completely turn it off.

I completely turn off T/C and AdvanceTrac every time I race. Heck, I turn them off every time I drive everyday as I love to drift the car, too. Nothing beats stearing with the rear tires on the street!

 

[Five Oh Brian]

Instead of looking at my best runs, I took a look at my average runs. I have all of my timeslips on a spreadsheet with averages calculated for each race day. I left out any botched runs if I missed a gear (very rare now that I have an MGW shifter) or if the launch went really sour (huge tirespin or big power loss). I compared a day in the spring that was very similar weather and DA versus my outing last Friday. The only difference was 3.73 gears in the spring versus 4.56 gears last Friday. I think the average numbers are more indicative of my issues than just my best runs before and after.....

3.73 gears / 4.56 gears

0.190 / 0.075 = R/T

1.982 / 1.780 = 60'
5.494 / 5.266 = 330'

8.266 / 8.105 = 1/8 mile ET
89.99 / 87.11 = 1/8 mile mph

10.637 / 10.538 = 1000'

12.617 / 12.577 = 1/4 mile ET
114.75 / 111.32 = 1/4 mile mph


So, my average ET is better the whole way down the track with the 4.56's, but my mph is down. So while my absolute quickest run of the season was with thte 3.73's, it was really a one-time fluke that I couldn't repeat. The 4.56's average much better off the line, are a little quicker, and are much more consistent with much less variance, but they cost me some trap speed.

The more I pour over the data from the entire season, the more I believe the 4.56's were a good choice for my car. Just gotta regain the trap speed with a good tune and some better breathing mods.

Thanks to everyone who has provided advice and insights into my quest for a faster Coyote!

 

[qwikhuh]

I was going to try switching to 4:56s but I just don't think the extra shift is worth it. I powershift every gear every time at the track and shifting 5th just didn't seem natural to me. If you are lifting every shift its going to kill your time and probably is causing that hesitation you are feeling. I would also check to see if you are pushing fluid out of your clutch reservoir, overheating clutch can cause the launch hang up you are having. I had the same issue when trying to ride the clutch out with 3:73s. I made the change to 3:90s and it made a very noticable difference although I am probably going back to 3:73s now that the car is going faster. Like the others said a good tune and a cold air kit will wake the car up for sure but I wouldn't waste the money on the boss intake, i saw zero usable gains with it

 

[19COBRA93]

I think you're onto something with averaging all your runs. You had picked out all your best 3.73 runs, but you only ran your 4.56's once. So you don't have a mass of runs to pick the best from those as well. For all you know, those runs with the 4.56's could be some of the worst out of all your upcoming runs.

My opinion, keep the gears, work out the tune, and get out there a bunch more times and let it rip.

 

[Five Oh Brian]

I was going to try switching to 4:56s but I just don't think the extra shift is worth it. I powershift every gear every time at the track and shifting 5th just didn't seem natural to me. If you are lifting every shift its going to kill your time and probably is causing that hesitation you are feeling. I would also check to see if you are pushing fluid out of your clutch reservoir, overheating clutch can cause the launch hang up you are having. I had the same issue when trying to ride the clutch out with 3:73s. I made the change to 3:90s and it made a very noticable difference although I am probably going back to 3:73s now that the car is going faster. Like the others said a good tune and a cold air kit will wake the car up for sure but I wouldn't waste the money on the boss intake, i saw zero usable gains with it

I just can't bring myself to powershift, if you mean not lifting off the throttle at all. This is my daily driver and I don't want to break stuff, even if I'm giving up a tenth or two in the process. I never thought about the clutch before, but the pedal always seemed fine with the 3.73's so I didn't even consider any clutch issues. I've never found any fluid coming out of th e reservoir, though.

I believe you're right about the Boss intake. The only noticable gains I've ever seen on anyone's dyno graphs are really above 7,000 rpm's, and I'm shifting by 7,200 rpm's anyway. And I won't spin a stock shortblock high enough to take advantage of the Boss intake's high rpm benefit.

I think you're onto something with averaging all your runs. You had picked out all your best 3.73 runs, but you only ran your 4.56's once. So you don't have a mass of runs to pick the best from those as well. For all you know, those runs with the 4.56's could be some of the worst out of all your upcoming runs.

My opinion, keep the gears, work out the tune, and get out there a bunch more times and let it rip.

My best runs with the 3.73's (12.15 and 12.27) were after long cool downs. Every run with the 4.56's was a hot lap as I was really focused on nailing my launch and getting lots of runs in to practice. That had been my biggest problem with the 3.73's that I was hoping the 4.56's cured (which they did). Racing Friday night was only from 4pm to 6:30pm (until dusk), so there just wasn't any time for a long cool down, hence the hotlaps. Best runs with the 4.56's were 12.37 and 12.40.

For comparison, Matt's (MindIfISmoke) '13 GT auto went 12.22 and 12.30 against me when I first arrived, then he promptly parked his car and cooled it down a long time, then went out and ran an 11.93 dropping 3 tenths off his times simply by cooling the car off. Makes me wonder what my car will run cold now, and I won't know until our local tracks are open again in the spring (last Friday was the last raceday of the season). My trap speeds are still a couple MPH less hotlapping the 4.56's vs hotlapping the 3.73's, but I have not run the 4.56's cold to shoot for that ideal cold run yet.

I'm babbling on and on about this, but thinking aloud as I type. You're right, keep the gears, get a proper tune, and run the car cold next time and see what happens. It's gonna be a long off-season waiting for the tracks to opn.

 

[retfr8flyr]

If you don't want to power shift then get a WOT box.


Earl