new hemi mpg in an Abody?

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SirDan

SirDan

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i was just wondering what kind of mileage you could get with a new hemi in an A body. i mean hell if the 5.7 can get 25 highway in the challenger its gotta get at least 30 in a dart rite? Not to mention having near 400 hp =P~
 
I think 25 is optimistic in an Abody. Really depends on transmission/rear gearing/tire size etc... Challenger's have the variable valve timing (mdx?). As a matter of opinion 25mpg in a Challenger is tought to do, I drive a 5.7 Charger regularly and it doesn't get close to 25mpg.

I don't know if many guys have been able to use the MDX in older car applications.
 
Theres a guy on here who has done it and IIRC he was getting 20 miles per gallon....Dean
 
rjsjea said:
I think 25 is optimistic in an Abody. Really depends on transmission/rear gearing/tire size etc... Challenger's have the variable valve timing (mdx?). As a matter of opinion 25mpg in a Challenger is tought to do, I drive a 5.7 Charger regularly and it doesn't get close to 25mpg.

I don't know if many guys have been able to use the MDX in older car applications.
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not all of them have mds the 6spd ones use a massive OD to get mpg up to 28 or so. It turns less then 1500 on the freeway doing 70 mph
 
Variable Cam Timing and MDS are completely different. VCT advances or retards the cam timing in relation to RPMs to maximize power and torque; MDS shuts off fuel, spark, and valve lifters to four of the eight cylinders when cruising to save gas. There might be a way to keep the two (or just MDS on pre-'09 engines) if using the stock engine computer but even without them you'd be pushing around 22-23 MPG on the highway and 17 or so around town. An A-body Mopar would be about the lightest thing you could easily put a new Hemi in, so it should be easier to get good mileage with the correct gearing.
 
There is a guy who put a 5.7 hemi and 545rfe trans into a 65 Corornet, with 3.55 gears he is getting 22-23 on the highway doing around 75mph. This car was in Mopar Enthusiast some time ago.
 
i think 70dart??? (the srt rootbeeracuda guy) was gettin 21 in his 70 dart 5.7 auto car. sorry about the name lol his build hasnt came up in a while so i havent seen it
 
That would be me. I'm getting 22-23 MPG out of this thing--lovin' it.

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FWIW, I get 21-22 mpg in the Cuda with a carb'd 360 A833OD and 3.55 gears at 70 mph.
 
driving habits make a difference too. I know if I had 400 horses under the hood I would over feed them all.
 
Gee and the 5.7 in my Ram only gets 8 to 10 mpg. May be I should just put the motor in a Dart.
 
I get 18 in mine on the highway doing 75mph . Mine has 833 4 speed with 3.91 gears and a 27" tire.

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I didn't realize there was that much difference in the accessory locations between the engines (5.7 and 6.1). Difficulty level on the installations? They both look like very clean. Details, details, details. :cheers:


Wylde1.

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Just FYI, I am averaging 20 mpg combined in my 2009 Classic 6 speed. On a road trip over the Cascades with a couple of blasts into triple digits (had to safely pass that semi...) I got 24 mpg. In an A body you should be able to get in the 20's consistently. And yes it is hard to keep from waking the 385 ponies. I don't have the multi displacement feature. As Ross said, they use an overdrive 5 and 6 to allow good highway mileage. 1500 rpm at 70, but still good torque. Never feels like it is lugging unless you want some neck snapping acceleration or going up a big hill.

Great looking installs in your A Bodies guys. Well done.

Mike

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Huge difference between the truck 5.7 and the car 5.7. Both car 5.7 and 6.1 use the same acc. locations, the truck is mounteed up high. Hope this helps.
 
if i had money... nice builds guys i like the first 5.7 hemi that was done it looks really good
 
5.7 hemi said:
Huge difference between the truck 5.7 and the car 5.7. Both car 5.7 and 6.1 use the same acc. locations, the truck is mounteed up high. Hope this helps.
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Thanks for the info. Does the car acc. location make more a more difficult install? Obviously by looking at Gdemon's car it can be done.


Wylde1.
 
Sure you can do it, but it take more fab work on the passenger side frame rail---got to cut a small notch out for the alt., and there is something else that I'm forgetting, someone will chime in and say what it is. This is for the stock k frame, an Alter K will be more flexible. With the truck set up, you dont have those problems.
 
Hi

No frame mod on the passenger side of mine for the Alt. Its tight but it cleared. the toughest part is the A/C compressor. I had to make a bracket to move the compressor up about 3" and eliminated the Power steering pump.

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Are you using the stock k frame or an alterk? I say this because most people have to notch the factory k frame, and the alterk allows you position the engine if you want. Now some frames where a tad wider due to "bad" tolerances from the factory, I mean the lip of the frame rails. B and E bodys really dont have that concern since they are wider to start out with.
 
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