Supercharger Coming in Spring- What Supporting Mods am I missing?

[robvas]

Example:
"I've got a Whipple car as well making 885rwhp and swapped my factory 3.55 for the 3.31's. Much better and I can cross the trap in 4th gear instead of having to shift into 5th."

Then ten speed auto has 7 forward gears that aren't overdrive. The MT82 only has 4.

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[robvas]

Way back when guys started to T56 swap the SN95 Mustangs they figured this out. They had to go with 4.10 or 4.30 gears to get that same 'pep' because the gear ratios were a lot taller than the T45 factory 5 speed trans.

It was very obvious on the launch because you're looking a 2.66 or 2.97 first gear instead of a 3.37

Now, the MT82D4 is geared almost identically to the wide-ratio T56, except the first gear is 3.23. That fixes the launch. Let's also remember that the wide-ratio T56 was always the 'bad' choice when it came to the 1/4 mile, so that adds to it. You wanted the close-ratio T56 for that (2.66, 1.78, 1.30, 1.00, .80, .62), which is what the Terminator Cobra came with.

Remember the old MT82 (and the Tremec used in the S550 cars, although not the exact same ratios) had shorter gears, and 5 gears until you hit overdrive instead of only 4. So 3.73's are just fine (even though some people act like those are too short and you'll never get traction. Like 3.55 is going to be that different). Then again there are the people who don't realize how little RPM difference there is between those two on the highway...

Somewhere along the line, people started saying 'longer gears are better for boost' and people kept repeating it without actually thinking about it.

Add this to the fact that you're going to spin a Coyote another 1000-1500rpm (or more) higher than you are going to turn a 4.6 Cobra engine (stock for stock).

Back to the S650 with the 6 speed manual.

3.55 gears, 7500 RPM, 27" tire

Common 'drag racing wisdom' says you want to cross the 1/4 mile in your 1:1 gear (4th in this case) nearing redline. You can't always do this, especially with how high redlines are these days, tires have gotten taller, and you might not need to since you have 6, 8, or 10 gears in today's transmissions.

For example, let's use a naturally aspirated S650 Mustang with a couple bolt-ons, you might trap 120mph, which means you will be hitting redline as you cross the end of the 1/4 mile in 3rd gear. Not the end of the world. If you switched to 4.09's, it might be a little faster, but you now have to cross the line in 4th, and you've introduced an extra shift. You're getting off the power for a little bit, and that might cancel out any gains you make by changing the gearing. So it's a draw between 3.55 and 4.09's. Unless you're banging gears and launch on slicks at 6k rpm to get the holeshot.

You can notice a similar thing in some cars (again depending on the gears) if you do a 60-130, where you might as well just start in 3rd, because starting in 2nd keeps you there for just a short while and doesn't make any sense because you have to shift right away.

Enter the Whipple.

You're now going to be trapping higher than 120mph. So you have to shift to 4th gear no matter what, so you need to make the most of it. The problem now becomes that you hit 4th gear at 120mph, and you're at 5200rpm And then you cross the finish line at say, 135mph, and you've only gotten up to 6000rpm, because you're geared to go 170mph in 4th gear with 3.55's.

Let's look at a dyno chart of a Whipple S650 for a minute.

So from 5200 to 6000rpm you are only making ~550hp when you shift and 700hp when you are at 6000rpm (these are 'crank' numbers not wheel so they sound better than they are). You're just using the middle of the engine's powerband.

Let's switch the 3.55's to 4.09's. You shift into 4th gear and you land at the same 5200rpm. However, when you reach 135mph (and you'll probably make it higher than that because you're making more power this time around), you're now going to be at 6900rpm (136mph). And at 6900rpm, your engine is making right about 800hp. Plus, the power is moving the car with more energy in every gear because of the 'mechanical advantage' of shorter gears.

Using the higher part of the power band with the shorter gears is a huge deal.

Hellcat guys only spin their engines to a little over 6000rpm so they don't want to go over 3.09 or whatever they are because they will run out of gear in the 1/4 mile. When you have 75-8000rpm to play with you can use more gear.

 

[Junkyard Dog]

Then ten speed auto has 7 forward gears that aren't overdrive. The MT82 only has 4.

I am pretty sure the remark in quotation marks is from a 4 speed guy (MT82), gearing his car with the Whipple to use 4 gears in the quarter mile without having to shift into the first overdrive gear (5th). He found that 3.31 are what he needed. He had 3.55 prior.

Anyway, I just wanted to point out what others are doing, and why.

It is really remarkable, when you think about it.

In 1983, those of us who were modifying our 10-15 year old muscle cars for acceleration never had the kind of horsepower under the hood even to think about installing taller (lower numerically) gears in the ring and pinion because we were running out of rpm in the 1:1 gear at the end of the quarter mile (no overdrives back then). We were all leaning toward 4:11 (the standard) or 4.56 (for the really dedicated). 3.31???? And here are lots of Mustang owners installing blowers and reaching speeds where they need a 3.31 to keep from over-revving the engine in 4th gear. I mean, it really is an exciting time.

 

[robvas]

I am pretty sure the remark in quotation marks is from a 4 speed guy (MT82), gearing his car with the Whipple to use 4 gears in the quarter mile without having to shift into the first overdrive gear (5th). He found that 3.31 are what he needed. He had 3.55 prior.

If you look at his posts he isn't doing this with an MT82D4, so he doesn't have a 2018+ car so what he says doesn't apply. 5th gear is his 1:1

For a 2018+ car, you can go 170mph in 4th with 3.55's and 7500rpm

He's not doing that in the 1/4 mile with only 850hp

 

[Junkyard Dog]

If you look at his posts he isn't doing this with an MT82D4, so he doesn't have a 2018+ car so what he says doesn't apply. 5th gear is his 1:1

I did not know the MT82 was different in 2017 and earlier, so different that 5th is 1:1. I learned something new.

What a massive change.

The rpm drop on 7th generation GT manuals must be horrific, especially compared to my A10.

 

[robvas]

I did not know the MT82 was different in 2017 and earlier, so different that 5th is 1:1. I learned something new.

What a massive change.

The rpm drop on GT manuals must be horrific, especially compared to my A10.

I mentioned that in my big ass post above

 

[Junkyard Dog]

an MT82D4

D4 = "Direct 4th"




So now I learned two things today.

 

[Junkyard Dog]

A little help from the crowd would be appreciated.

Car is 2025 Mustang GT Manual with Performance Package and active Exhaust (301a).

I’ve got the Ford Performance supercharger being installed by my son at his Ford Dealership in Spring.

Prior to, I’m compiling the following mods to be installed as supporting the build…

Already purchased:

1) Steeda Stop The Hop Kit (Street Starter)
https://www.steeda.com/Steeda-S550-Mustang-Stop-The-Hop-Starter-Kit-555-4455
2) Steeda GT500 Vertical Links with Poly Bushings (NOT DELRIN)
https://www.steeda.com/steeda-555-4137-mustang-vertical-links-polyurethane-bushings

Likely adding the GT350 Halfshafts and looking at Wheels / Tires to fix traction.

Likely going with an SVE Wheel for cost and weight savings with Michelin PS4 Summer Tires.

I’ve already got my wheels / tires up for sale - asking $1200 with center caps and sensors with 2400 miles on them. Let me know if that’s reasonable.

Already have the AOS from Ford Performance installed. I’ll have to modify it when the supercharger goes on.

I'm trying to make supporting mods that don’t add NVH- I’m too old for that crap - and has to fit in with the wife acceptance factor.

What else does everyone recommend that won’t add NVH (none of the above will per Steeda) but will help with putting the added power down? Or am I in a good spot with that I’ve acquired so far?

BTW Reached out to HPP (DFW Chevy/Ford Performance Shop) and they quoted me 8 hours to install the Steeda parts at $1500 … my son and I will be doing it ourselves at the dealership after hours. That’s just obscene. Steeda themselves states 3-4 hours if you don’t know what you’re doing. .

Who knows maybe I’ll build a Shop for my son and I on our back property and we can do work on the side at a reasonable price .

TIA

Very nice looking house, Stanzi. Curb appeal. I really like the stone siding, the dark brown doors and trim, the curved tops to the windows, and the way the roofline looks at the front, with the changes due to the garage and what looks like a front door portico.

 

[needforspeedirl]

A little help from the crowd would be appreciated.

Car is 2025 Mustang GT Manual with Performance Package and active Exhaust (301a).

I’ve got the Ford Performance supercharger being installed by my son at his Ford Dealership in Spring.

Prior to, I’m compiling the following mods to be installed as supporting the build…

Already purchased:

1) Steeda Stop The Hop Kit (Street Starter)
https://www.steeda.com/Steeda-S550-Mustang-Stop-The-Hop-Starter-Kit-555-4455
2) Steeda GT500 Vertical Links with Poly Bushings (NOT DELRIN)
https://www.steeda.com/steeda-555-4137-mustang-vertical-links-polyurethane-bushings

Likely adding the GT350 Halfshafts and looking at Wheels / Tires to fix traction.

Likely going with an SVE Wheel for cost and weight savings with Michelin PS4 Summer Tires.

I’ve already got my wheels / tires up for sale - asking $1200 with center caps and sensors with 2400 miles on them. Let me know if that’s reasonable.

Already have the AOS from Ford Performance installed. I’ll have to modify it when the supercharger goes on.

I'm trying to make supporting mods that don’t add NVH- I’m too old for that crap - and has to fit in with the wife acceptance factor.

What else does everyone recommend that won’t add NVH (none of the above will per Steeda) but will help with putting the added power down? Or am I in a good spot with that I’ve acquired so far?

BTW Reached out to HPP (DFW Chevy/Ford Performance Shop) and they quoted me 8 hours to install the Steeda parts at $1500 … my son and I will be doing it ourselves at the dealership after hours. That’s just obscene. Steeda themselves states 3-4 hours if you don’t know what you’re doing. .

Who knows maybe I’ll build a Shop for my son and I on our back property and we can do work on the side at a reasonable price .

TIA

As is typically the case, the crowd has gotten off topic. You’re adding a lot of good parts so far. In order of importance I would add:
1- catch cans
1.1-headers with no cats or at the very most green cats. If you can’t go catless I would not be doing track days or long highway pulls back to back.
1.2-cat back exhaust with H pipe and resonators
2- 170* thermostat
3-boost a pump
4-custom tune
5-DOT drag radials or R type tires if you want to put the power down from 0-90mph
6-Aluminum drive shaft
6.1-uprated clutch and lightweight flywheel
7-lowering kit that allows you to adjust camber so that you can tuck some wider tires in the rear 315’s do nice with the correct offset of 50-55 mm on an 11” wide wheel.
8-aero
9-weight reduction
10-parachutes at this point

 

[Junkyard Dog]

It’s already got the Dark Horse radiator in it from the factory as part of the Performance Package…

That should be sufficient.

This one is a little thicker
https://driftamerican.com/2024-must... PWR,radiator face, enhancing fan performance.

But wait and see if you need extra cooling. A lot depends upon how you are going to drive it. Quarter mile pulls with some cool down time are being done all over the country with no issues with the current cooling system.

 

[Junkyard Dog]

Smooth Boost boost controller.

This suggestion may have gotten lost in all of the transmission discussion.




and

 

[robvas]

This one is a little thicker
https://driftamerican.com/2024-mustang-gt-42mm-performance-radiator/#:~:text=2024+ Mustang GT 42mm Performance Radiator by PWR,radiator face, enhancing fan performance.

But wait and see if you need extra cooling. A lot depends upon how you are going to drive it. Quarter mile pulls with some cool down time are being done all over the country with no issues with the current cooling system.

You don't need it for a single 1/4 mile pass but the street is another story. ECT basically starts going up when you do a pull so to help with detonation resistance and overall performance I want everything to be as cool as it possibly can.

 

[Stanzi]

This one is a little thicker
https://driftamerican.com/2024-mustang-gt-42mm-performance-radiator/#:~:text=2024+ Mustang GT 42mm Performance Radiator by PWR,radiator face, enhancing fan performance.

But wait and see if you need extra cooling. A lot depends upon how you are going to drive it. Quarter mile pulls with some cool down time are being done all over the country with no issues with the current cooling system.

Thanks for the link!

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