383 STOCK B body vs 5.7 Challenger

[Dennis H]

Terms I know are Crank or Bench HP and Chasis Dyno.

 

[BSB67]

The gear multiplication does make a difference. Look at the numbers:
1968 Road Runner
727 1st gear 2.45. 833 4 speed 1st gear, 2.64? Axle gear of 3.55 to 3.91. Multiply the axle gear by the 1st gear and second.
727/2.45 X 3.91 = 9.57.
833/2.64 X 3.91 = 10.33. Now consider the gear ratios of the new stuff. They shuffle around a bit. The A/T cars often have a 3.06 diff and a 4.71 1st gear. 3.06 X 4.71 =14.41 ! The 6 speed manual uses a 3.90 diff and a 2.97 1st gear. 3.90 X 2.97 = 11.58.
The gearing gets the car moving much quicker.

Not as much as you think. Tire is still limiting on the 60 ft. Both cars from the 60s and late model are at 2.0 60 fts. From 60 ft to about 150 ft, the extra gearing will let that car pull ahead about 1/2 car, all else being equal, then after that the gearing has no effect. If the modern tranny has a narrower shift recovery that will help going the rest of the way down the track. Plus they they have flatter and longer power curves due to the wide LSA and variable valve timing.

 

[Dennis H]

Getting complicated. I’m out.

 

[1967coronet440]

My 4200 lb bone stock 06 Charger srt8 ran 13.6 spinning out of the hole. Rated at 425hp from the factory, now it has a custom tune, true cold air intake where the filter is down in the lower front bumper where the brake cooling vent used to be. long tubes, hi flow cats and cat back exhaust. Haven’t been back to the track since

 

[Dennis H]

Lied, I’m back. My 2 rides. Don’t care which is faster. The one with the Panache is Yellow.

 

[Kern Dog]

The gear spacing in the 5, 6 and 8 speed transmissions is so much closer and better than in the 3 speed 727 models. Driving the 2015 R/T, it rarely feels soggy or like it is in the wrong gear.
The Charger is another story. Sure, torque is important but so is the leverage that optimal gearing can provide.

 

[dvw]

Though I love my old stuff the new stuff is great. Yesterday I drove my sons Scat pack Challenger from Detroit to South Carolina. Handles great, A/C, and got 25mpg on the trip . It's been 12.01@115 with a tire swap and tune, 4550lbs.
Doug

 

[mmissile]

I race "stock" musclecars with my Caravan. I've beat more than one.

 

[BSB67]

The gear spacing in the 5, 6 and 8 speed transmissions is so much closer and better.....

Correct, the narrower shift recovery helps as gears are added. But in my limited experience the 5 and 6 spds don't really narrow the shift recovery much as they are mostly adding ratio down low, and up high over the 3 speed. Now an 8 spd with a 1000 rpm drop between gears is meaningful in et and mph.

All that said, if you removed a 383 from a 3700 lb B body that ran the typical 14.5 @ 95 mph, and changed only to a late model 5.7, my money says that it would run low 13s and I bet the mph would be 105 - 106.

 

[BSB67]

I race "stock" musclecars with my Caravan. I've beat more than one.

Same. I've lost a couple too. But it's always close enough where there is only one person embarrassed.

 

[beanhead]

We could go on and on...our ford edge's 6 is rated at 315hp/350tq (better than all but the 440s and 426s of old) and has the infinite traction of awd, and a paddle-shiftable 6-speed auto...in the light-to-light world it moves past all but the more seriously equipped vehicles with ease and quietly hums down the freeway at any speed. Point I guess is, who cares! Granny's SUVs can be fast nowadays or capable of it, but there's simply NO comparison to driving around in an old-school car, fast or not...people don't wave and honk and thumb's up us when we're driving the edge around..there must be a reason!

 

[BSB67]

Certainly there are many aspects to the hobby for people to enjoy well beyond performance. Arguably the majority of enthusiasts don't prioritize performance. But I believe that there are still a few guys around like me that do care about the performance of their muscle cars. All of the other attributes of these cars rings hollow for me if there is a lack of performance. If all there was is cruising around and getting thumbs up from passersby, and going to car shows and talking about some hard to get window crank, I'd sell my cars right now.

 

[Cranky]

It’s all about the engineering. Hi tech vs 1950’s tech. Multi port fuel injection, computer adjusted optimum air fuel ratio for rpm, load, and weather, roller can, variable valve timing, transmission gear ratios, etc, etc.

It isn’t right but it is so.

Car's of the late 60's were way ahead of any car from the 50's!

True, and the fact that it will vary the mixture to compensate automatically...

I always liked to tune for consistent performance in any kind of weather since I bracket raced most of my street rides. It's always nice to be able to go out to the track, run one time trial and it would run what it did last time out when the weather was hotter or even cooler. Then all I had to do was try and cut a good light! My old high 10.60 would run 10.50's with tuning but with two inline carbs on a TR, heck with messing with that! I could change my dial by leaving at an idle vs stalled up to 4500....and even then, it only changed .01

 

[beanhead]

Certainly there are many aspects to the hobby for people to enjoy well beyond performance. Arguably the majority of enthusiasts don't prioritize performance. But I believe that there are still a few guys around like me that do care about the performance of their muscle cars. All of the other attributes of these cars rings hollow for me if there is a lack of performance. If all there was is cruising around and getting thumbs up from passes by, and going to car shows and talking about some hard to get window crank, I'd sell my cars right now.

Amen!

 

[Sweet5ltr]

I'd stick my neck out to say that the new stuff probably has LESS parasitic losses from flywheel to tire than the old stuff. I'll bet a 376 HP 5.7 makes a greater % of net HP than a classic does.

And you would be absolutely correct.

 

[BSB67]

And you would be absolutely correct.

Do you have any data on this? It would be interesting to see. It makes sense that there is a lot of effort by the auto makers to eliminate theses losses as much as possible and probably have come a long way, but the flip side is 8 speed autos would have more parasitic losses over a three speed by their nature, I would guess.

 

[Kern Dog]

I wish I had the actual data in front of me but I have seen dyno sheets of stock late model cars as well as classics. The net/Wheel Hp numbers on late models seem a lot closer to the flywheel rating compared to the classics. Now, some of this could be attributed to exaggerated HP claims of old engines, also you can factor in that they were GROSS rated.

 

[BSB67]

I wish I had the actual data in front of me but I have seen dyno sheets of stock late model cars as well as classics. The net/Wheel Hp numbers on late models seem a lot closer to the flywheel rating compared to the classics. Now, some of this could be attributed to exaggerated HP claims of old engines, also you can factor in that they were GROSS rated.

Yes. That's the problem. Needs to be two motors on engine dynos, followed by those to engines in their respective cars on chassis dynos.

And generally it is a double whammy. The old engines are not only gross HP, but exaggerated too. Plus, the way "net" is measured is different too. The auto companies don't use what your local speed shop uses. Your local shop uses the standard that gives the highest possible results of all the standards used. I think ma Mopar in other published info put the 383's HP at 290 hp

 

[Kern Dog]

Mopar Muscle did some good reporting in the early 2000s with Randy Bolig as editor. Over the course of a few years, they built a 340, a 383 and a 440 all to stock specs, dyno tested them, then added typical performance upgrades to show the results.
Fuzzy memory here but I recall the 440 showing an adjusted number of somewhere between 330 and 350 HP. It may have been the same magazine many years later that tested the parasitic drag of the fan, water pump, alternator and power steering pump. The heavy RV-2 A/C pump surely cost some HP but every 440 4 barrel from 1967-70 seemed to be rated at 375HP whether they had P/S or A/C or neither.

 

[biomedtechguy]

Even with 315/35/17 Toyo Proxes TQ drag radials, I am having trouble with off the line traction. I'm working on various solutions, but the inability to launch any higher than 1k RPMs is hurting my 60ft times badly and my 1320 time as well.
Having said that, when I was running 13.8s at 104 I was neck and neck with a 2010 SRT Challenger.
Now the last time I ran I had not yet switched out the 3.54s and 4 speed for my current Passon a855 5 speed (which shifts great under power at the track) and 4.10 gears. The last "track day" before those changes I was running 13.3 at 106, I would have beat that Challenger every time, and I beat my friend's SRT Jeep 3 out of 3...