Magnum 300 crate engine - how should it go when tuned up right?

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The G tech tells the tale. You have what 300 gross horsepower feels like in a 40 year old 3600lbs car. The Mustang is 460 net hp, with extra gears in the transmission. You need another 100hp and more gears to equate those cars. But - the A body will turn heads. Nobody gives a **** about another Mustang.
 
moper said:
The G tech tells the tale. You have what 300 gross horsepower feels like in a 40 year old 3600lbs car. The Mustang is 460 net hp, with extra gears in the transmission. You need another 100hp and more gears to equate those cars. But - the A body will turn heads. Nobody gives a **** about another Mustang.
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stixx said:
^^^^^^^^^^^^^^^^^^^^^^^^^THIS.
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That's funny. I do give a **** about Mustangs! I don't actually give a **** about you being wrong on that point though. :)

My Mustang is a 2011. That was the first year for the Coyote and it was rated at 412hp. I ordered it stripped ("300A" package) with just the optional axle ratio and the big brakes. Guys with similar cars have weighed them and they often come in just under 3600lbs. Not bad for a modern-ish V8 car.

It is a cheap, relatively fast, relatively light, easy to maintain, durable, reliable, V8 Coupe with a manual transmission that flies under the radar. It even has a huge trunk and is pretty damn practical. Like the A-Body, it was an untouchable performance bargain for the dollar at the time.

You'd think a car like that might appeal to people who appreciate Mopar A-Bodies. How many people "gave a ****" about a Duster back in 1975? Go figure.

I have to be honest, the car tribalism thing is really starting to look stupid to me.
 
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The Magnum has only 245 net hp in my jeep. In your Duster probably slightly higher net hp, so if comparing to your mustang it be a night and day difference. The V6 in my Avenger RT has more net hp then the 5.9.
 
You have 0-60 in the 6 second range. That's right on top of the factory 340 cars. That's about exactly where it should be.
 
RustyRatRod said:
You have 0-60 in the 6 second range. That's right on top of the factory 340 cars. That's about exactly where it should be.
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Thanks. That perspective is appreciated.
I took for granted that a car with much wider/better tires should have a big advantage (along with a more efficient transmission)...but since those factors were likely not the biggest impediments to the old 340 cars, they might not make that much difference. Being comparable to a stock 340 car is probably a good sign that the car isn't way out to lunch on performance.

Are the 4.10s a better match for the 727 ratios?
 
RustyRatRod said:
You have 0-60 in the 6 second range. That's right on top of the factory 340 cars. That's about exactly where it should be.
Click to expand...

Thanks. That perspective is appreciated.
I took for granted that a car with much wider/better tires should have a big advantage (along with a more efficient transmission)...but since those factors were likely not the biggest impediments to the old 340 cars, they might not make that much difference. Being comparable to a stock 340 car is probably a good sign that the car isn't way out to lunch on performance.
 
MRGTX said:
That's funny. I do give a **** about Mustangs! I don't actually give a **** about you being wrong on that point though. :)

My Mustang is a 2011. That was the first year for the Coyote and it was rated at 412hp. I ordered it stripped ("300A" package) with just the optional axle ratio and the big brakes. Guys with similar cars have weighed them and they often come in just under 3600lbs. Not bad for a modern-ish V8 car.

It is a cheap, relatively fast, relatively light, easy to maintain, durable, reliable, V8 Coupe with a manual transmission that flies under the radar. It even has a huge trunk and is pretty damn practical. Like the A-Body, it was an untouchable performance bargain for the dollar at the time.

You'd think a car like that might appeal to people who appreciate Mopar A-Bodies. How many people "gave a ****" about a Duster back in 1975? Go figure.

I have to be honest, the car tribalism thing is really starting to look stupid to me.
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Glad you took it in the spirit it was presented...lol.
If I was to buy a modern car it would be a Mustang, because the value is high and the cars look decent, plus I can get what I want in one. I've already looked a little a couple years ago. The Mopar offerings are just too expensive or ugly. Tribalism is what it is. Everything we do seems more stupid to me lately, but that just might be my age...lol.
 
MRGTX said:
I'm a novice when it comes to tuning so I could use some perspective and advice here.

So far, I have ~750 miles on the Magnum 300 that I bought used from a good guy here on the forums. The motor is tight, doesn't burn oil, good oil pressure, no leaks...idles great too.

Performance isn't impressive at all.

So far, I haven't messed with it too much but subjectively, it doesn't feel that much better than the stock 318 2bbl when it was running at its best, especially in the low rev range. The Demon 650 carb is probably due for a rebuild (this winter), there's probably some timing advance left on the table, carb could probably be leaned out a bit...so I know it's not optimized. Yes, I realize that this is a mild motor with relatively low compression and a very tame cam but on paper, I thought my setup would be a bit more lively.

Stock cam/heads
Demon 650cfm
Mopar Performance M2/dual plane
Doug's long tube headers through 2.5" (no crossover)
4.10 axle ratio/27" tall tires
2600 rpm stall
Mildly built A904
5900 RPM governor weight, TF2 shift kit

What would you change first?

I'm still running a steel fan (electrics are sitting in a box), mufflers are probably restrictive (cheap-o Summit type)...could those be pulling off that much power?

In CT, we have access to 93 octane...how much timing can folks get away with? ?

Any thoughts are welcome.
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!!
 
The biggest part of your power is heads what you can flow through your heads if you don't want to mess with the stock components then the next thing you need to go to his timing on a normal engine it takes 40 degrees and timing to 42 total advance in a really efficient racing set-up usually start at 36 you can also check your plugs if your plugs are burning yellow or gray it's not too lean it's not too rich. IF the timing is too retarded, the mark on the plug will be closer to the body of the plug if it's too rich the mark on the plug will be towards the end of the plug so you advance or retard the timing to make the line on the plug be right in the middle of the turn. Then you can jet the carburetor to lean It Off or richen it up whatever you need to do
 
moper said:
The G tech tells the tale. You have what 300 gross horsepower feels like in a 40 year old 3600lbs car. The Mustang is 460 net hp, with extra gears in the transmission. You need another 100hp and more gears to equate those cars. But - the A body will turn heads. Nobody gives a **** about another Mustang.[
I built 340s over 20 years and raced A LOT of chevys and quite a few Ford's, I did not hesitate to build a 340 and put it up against any small block Ford or Chevrolet car and did for many years and was very successful at it. Had a blast racing sb mopars against more chevys than I could count. It was more expensive to set up a mopar versus a Chevy in the beginning but they lasted much longer than the chevys did . My brother raced a 4 speed 65 mustang and he sprayed and couldn't beat me. I know those were slower times but I think they were more fun than now as it was a lot harder to know how to do a good tune on a car then versus the computerized age now. MY car started at 14s and went to 9s w a steel headed, stock crank and rods 340. That's not slow for cars even now.
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