Anybody Modding Sports Cars or Muscle Cars?

[hayden55]

I'm coming from a 2010 Mustang GT that I won't be keeping but am looking into hopping into another 05-06 GT down the road. What is everyone doing to their cars and what changes are you seeing? My car was an auto and I was always in the upper rpm's averaging 12/21 (at 90mph) but I have had friends with Stick cars get 30mpg regularly going 70-75. Looking forward to see some responses!

[Gasoline Fumes]

This one is my favorite!
Details: 2012 Mustang 3.7/M - 2012 Ford Mustang 3.7 Fuel Economy - EcoModder.com

[V6MustangFTW]

I've got a 98 Mustang V6 5 speed with an underdrive pulley and a partial lower grill block. Not sure if the grill block helped but the pulley definitely brought my mpg up. I'll be installing a catback soon and I'm thinking about an air dam, lowering springs, and maybe a little weight reduction. Currently gets around 24 mpg and I don't hypermile it. Glad to see more Mustangs on ecomodder!

[Ecky]

Underdrive pulley seems like a good idea.

Honestly though, the largest improvement will be from slowing down. I can increase MPG in my Insight from 55-60 to ~100mpg just by slowing down from 75 to 50-55mph.

[serialk11r]

I've been a "sports car" driver since I got my first car. Although my "sports cars" all have small engines, I have contemplated getting a faster/heavier/thirstier car.

IMO when it comes to these cars, this is the checklist:
1. Unless the car is really cheap or ugly, don't go too crazy on body modification for aerodynamics, just do the underbody, maybe a spoiler if you don't mind reduced visibility out the rear. If the car is really cheap, maybe replace the mirrors with smaller ones to get lower drag.

2. Usually sports cars are geared short. If first gear is more than adequate for taking off from a stop, I'd toss some slightly bigger tires on the rear wheels for "taller gearing".

3. The engine of a sports car is usually wasteful, but it would be strange to reduce the peak power of the car. For a NA engine, I'd maybe do a cam regrind to get more "Atkinson cycle" at low rpm and shift the powerband slightly higher. This way your throttling losses are reduced, and if you want to go fast, just drop down a few gears and hear the engine music.

4. Mods that both make the car faster and more efficient are great. Switching power steering to electrohydraulic or electric is probably the biggest one. Weight loss is great, electric water pump or underdriven pulley is great.

[oil pan 4]

I have a 454 engine in the machine shop getting bored and stroked out to 489.

The engine is getting aluminum heads, intake manifold and headers saving a little over 100lb.
The compression is getting bumped up from turn of the (19th) century 7.9:1 compression to 1960s muscle car era 11:1.
Conversion from 1950 style flat tappet to roller everything valve train riding on a slightly advanced 270 grind cam. Advancing the cam timing will improve fuel economy, low end response and torque at the cost of high end horse power on an engine that could produce 500hp and 600 torque easily I can give up some on the highend.

To help save fuel I developed a switchable cold air to warm air intake I mostly developed before I pulled the old 454. Warm air at a controlled 90F when going down the highway and in town, cold air for when I open it up. No reason to run cold air all the time.
Lean burn, I tuned the current edelbrock 650 for lean burn. Which almost doubled fuel milage from the stock configuration. For the new engine I want to run an edelbrock 800, it should have a 1000 or even a 1200cfm but the 800cfm will give better results all around on the low end.
To encourage some EGR, with out an EGR I am going to run restrictive stock style exhaust system aided by cutouts when I open it up. No reason to run a wide open exhaust system all the time.
To prevent preignition I was going to use water methanol injection. I have already developed a pretty good water injection setup for my diesel.
This engine is going into my suburban now, but I am sure it will find its way into my Camaro in the next year or 2 depending on how often I go to Afghanistan.
This isn't what I want to do this is what I already bought parts for and is waiting at my friendly neighborhood machine shop for me when I return home. Some assembly will be required by me, which is pretty much everything the machine shop only did the machine work and bought most of the parts at their special dealer rates.

[hayden55]

What was funny on my car is that the gt500 rear fin reduced my mpg by 0.4 down the highway using my old test trip (test trip mpg- 26.4, -1.5%). And it had lots of front undertray around the motor. I had to pull the one under the engine off because it made the front end "flutter" so much from the turbulence under the car it caused. With the tray installed the hood moved at 75mph the same amount it did at 120mph without it! Helped with NVH cruising down the highway as well. Overall dropping the car 1.5-2" and removing the under tray I never noticed a change in mileage from either.

https://drive.google.com/file/d/0B1A...ew?usp=sharing

[hayden55]

Mustang mod wise if you can think it, you can do it. I can put in a 5 speed, 6 speed, gear ratios from 2.73-4.56 FD, underdrive pullies, electric water pumps, I can even swap the hydraulic steering on any 05-14 mustang to EPAS from a junkyard 11-14 car but cost is around 1000$ and weight gain is like 40 pounds. Not really worth it since i'm into autocrossing and will eventually compete in a 300hp 4.6 vs 500+ 5.0's.
The only thing kind of ironic though is that if you have a v6, compatibility with half the mods I listed is kind of nulled out. lol
In it's current state it has the cats deleted, louder mufflers, tune, intake, charge motion control valves deleted (cmcv deletes: mistake, cold starts use more gas, less low end, no noticeable change in top end). Making 350bhp. Then full suspension: custom spec coilovers by me (Ground control, bilstein), adjustable: swaybars, endlinks, watts link) and 285/35/19's. And weight reduction here and there to take the car from 3600 to 3480. But i'd rather not "race turd" a $20,000 automatic muscle car and instead start with a 05-06 $6000 manual car, starting at 3450 pounds with the lighter pre gt500 frame.
I want to compete in a stock modified class with the car so my mods will have to be legal so: I will swap the trans from the tr-3650 with 5th from 0.68 to 0.62, then weight reduction from 3450 to 3200 base weight for the class. Build a small trailer to carry tools for the track and 315/30/18 wheel setup.

I wonder how he found his values for Cd and ft2 for the mustang. I'll have to go to his thread and read it after work!

[elhigh]

If you're devoted to keeping it Mustang, look up Ultarc and what he's done with his 3.7 kind of tips the paradigm of sports car ≠ fuel economy. Those are the kinds of numbers people are usually pretty happy to get with their Corolla, and even then they don't have the kind of power on tap Ultarc has.

Whether that can be achieved with a newer 'Stang and its engine choices is a different question. I would be VERY curious to have someone come here with a 2.3 EcoBoost and hypermile the nuts off it, and tell us how he did.

[hayden55]

Originally Posted by elhigh

If you're devoted to keeping it Mustang, look up and Whether that can be achieved with a newer 'Stang and its engine choices is a different question. I would be VERY curious to have someone come here with a 2.3 EcoBoost and hypermile the nuts off it, and tell us how he did.

MPGOMATIC did post a "hypermile" ish loop video with one. 42.9 at 60mph? But average was 27.9 on his tank.