True horsepower?

[yellow rose]

for reference>
'71 stock 340 Cuda........3600lbs+/-? with me
stock bottom end with .039 fel-pro's so poss/prob 10:1 or under.
add> ally dual plane intake,
add> 750DP Holley
add> .484/284 purple hyd.
add> small tube hdrs.
add> 3500 converter
add> 8x26" M&H slicks, 3.55's
add> MSD6A
best ET/mph = 13.28@101
= 302 fly hp
All runs made at SPR...

With your numbers (based on 3600 pounds) I get 285 FW HP. Also...you are leaving a bit on the table. At that MPH you could be in the 12.9X range.

 

[Hot Metal]

This was back in 1982, stock springs with snubber only and long shocks....wasn't Stocker type launches!
I used wallace for weight/hp calcs.. .a 12.98@103 is 325hp/3600 according to me.

Reckon your using the Moroso slide?

Later I added a Strip Dom int.
DC.590 solid
4200converter
4.30's
10x28's
850DP
1.75" race hdrs
same back end
= 12.43@108 = 370fly hp
stock 2.02 heads no porting

 

[yellow rose]

This was back in 1982, stock springs with snubber only and long shocks....wasn't Stocker type launches!
I used wallace for weight/hp calcs.. .a 12.98@103 is 325hp/3600 according to me.

Reckon your using the Moroso slide?

Later I added a Strip Dom int.
DC.590 solid
4200converter
4.30's
10x28's
850DP
1.75" race hdrs
same back end
= 12.43@108 = 370fly hp
stock 2.02 heads no porting

Yes, I grabbed the Moroso calculator. I also have a late 1960's Isky Dream Wheel somewhere. Those two are the most accurate I've found. The Wallace numbers seem happy to me.

 

[AJ/FormS]

O.K....a '69 340 at 275 hp was at the crank,no accessories
and a '73 340 was 240 hp at the crank with accessories?

And the major tuning differences were the Scr and ignition timing

In 1971,mine went 98mph @ 3330 pounds, that calculates to 247 hp. Pure stock,70Swinger 340 4-spd/3.55s, including the E70-14 polyglass tires..It had about 12,000 miles on it.I brought a trophy home that day. I turned 18 that summer.

 

[Hot Metal]

ok well if Moroso says 285hp for my on track hp, and factory stock is 275 or as some say its underrated, that don't say much for my add-ons/tuning
but if you go by wallace@302hp its more in-line perhaps. Basically then if you put the same 8x26" slicks 3.55 geared bone stock 727/340 '70/'71 Cuda it would run 13.3's from the factory?

 

[AJ/FormS]

ok well if Moroso says 285hp for my on track hp, and factory stock is 275 or as some say its underrated, that don't say much for my add-ons/tuning
but if you go by wallace@302hp its more in-line perhaps. Basically then if you put the same 8x26" slicks 3.55 geared bone stock 727/340 '70/'71 Cuda it would run 13.3's from the factory?

That' possible on account of the factory polyglass tires were still screaming going into 3rd gear. There had to be a half second in that alone.
The Manitoba government built a huge ditch to divert spring floodwaters around Winnipeg in the late 60s. The gates were about a half mile from our house, and had a concrete roadway over top. We used to go down there at lunchtime in grades 11/12 and see who could lay rubber the furthest. Swinger on Polyglass tires for the win! But you know,street tire technology was in it's infancy back then, and it hardly mattered what tire or how big it was, 340s just roasted them all. I owned that car for 4 years, and put 7 sets on the back, even running some custom slapper bars. She went 14.41 on those little Es
4.10s were a colossal mistake on the street. But after I blew the 3.55s up, This 18 yr old know-it-all said what the heck, the whole pumpkin, LSD and all was $65.00,sooooooooo in it went. That 340 blew a lot of stuff up, including itself,finally.

 

[cannucky]

et factored with weight eh ? I can run the 1/4 in about 120 seconds and weigh 225lbs how many hp do I have ? and how much TQ does that work out to ?

 

[Ben Drinkin]

et factored with weight eh ? I can run the 1/4 in about 120 seconds and weigh 225lbs how many hp do I have ? and how much TQ does that work out to ?

I don't know **** about torgue and hp, but you run fast! It takes me three beers and two Camels to go a guarter mile...

 

[AJ/FormS]

et factored with weight eh ? I can run the 1/4 in about 120 seconds and weigh 225lbs how many hp do I have ? and how much TQ does that work out to ?

Well I'm about 225. I can't run a qtr mile at all anymore, but maybe a 100 yards in maybe a minute and no matter how I run the numbers, I can't get even 1 dogpower much less a horsepower.

 

[MOPAROFFICIAL]

This 18 yr old know-it-all said what the heck, the whole pumpkin, LSD and all was $65.00,sooooooooo in it went. That 340 blew a lot of stuff up, including itself,finally.

Killer deal , acid n all. No wonder Aj....its no wonder at all. ;) jk

 

[cannucky]

wouldn't want to try the mile anymore but I ran the 6 minute mile every September for gym class in High school and the 200 meters in less than 30 seconds thats and 1/8th mile pretty sure I could pull off a 2 minute quarter , maybe 2.5 thats still 150 seconds lol .
They used to give us a 100% for the term if we could do 1.5 miles in under 9 minutes but that last 1/2 mile got me every time best was 9.03 .

 

[Hot Metal]

That' possible on account of the factory polyglass tires were still screaming going into 3rd gear. There had to be a half second in that alone.
The Manitoba government built a huge ditch to divert spring floodwaters around Winnipeg in the late 60s. The gates were about a half mile from our house, and had a concrete roadway over top. We used to go down there at lunchtime in grades 11/12 and see who could lay rubber the furthest. Swinger on Polyglass tires for the win! But you know,street tire technology was in it's infancy back then, and it hardly mattered what tire or how big it was, 340s just roasted them all. I owned that car for 4 years, and put 7 sets on the back, even running some custom slapper bars. She went 14.41 on those little Es
4.10s were a colossal mistake on the street. But after I blew the 3.55s up, This 18 yr old know-it-all said what the heck, the whole pumpkin, LSD and all was $65.00,sooooooooo in it went. That 340 blew a lot of stuff up, including itself,finally.

Before I bought that '71 340/727 car I had a very nice near pure stock '71 340 Cuda Stick car in met brown, forget the actual color name, I remember taking it to SPR for a couple of runs with some old what we called "cheater" slicks, they were not much better than road tyres but if you fried them they worked reasonable, that went a best of 14.48 at around 97mph, taking it relatively easy so there might have been a low 14 in it if I gave it all the beans.... I just cannot see any stock 340 3600lb car running 101mph with 3.55/8" slicks, but whatever were just trying to talk "true hp" and using actual track times is better than speculating whether they were underrated or not, they were/are just an amazing motor.