Wow! Talk about bring a thread back from the dead!
Cheapest ways to increase power
- Thread starter '70-Challenger
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Well here it comes, I love math. A stock 225 has a bore of 3.40 and stroke of 4.125.That makes a swept volume of 613.7cc. And an 8.2 C/R would be 613.7 /7.2 =85.24 TOTAL combustion chamber volume.
Okay, now,I don't recall the shape and size of the slanty chamber, cuz I've never been into them, but Ima gonna guesstimate that cutting the chamber.100 will be about 13cc.
So 85.24 less 13cc =about 72cc,total chamber volume. Then (614+72)/72 yields 9.5 the new CR.
This is a math only exercise, and compares the Total chamber volumes.
That's what I built my one-and-only slanty to. It helped a bit.
But; if you wanna take off briskly, there is absolutely no mods you can do to your NA slanty that will wake it up, like gears. NONE, ZIP,NADA. Going to 3.91s from 2.76s is 3.91/2.76=Plus 41% increase in torque,ACROSS THE BOARD, and a much, much, quicker romp thru the gears. If you have never had back to back rides in a car with this much gear swap, it is phenomenal!Your slanty will feel like it grew 92cubes and became a teener.
OOPs
The sacrifice is no more comfy hi-way cruising, and no more saving gas, cuz 65 will be pushing 3300rpm. Thats a lotta buzzzzzz. But that is the penalty for the lack of cubes.
Oops
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That's true!
I'm not going to read through this to see why you posted a "disagree" to my post 5 years later.
Maybe you'd care to explain? If I disagree with someone, I explain myself. Nicely, of course! What up?
diymirage
HP@idle > hondaHP@redline
Look at what forum you are in, and then look at the advice you gaveI'm not going to read through this to see why you posted a "disagree" to my post 5 years later.
Maybe you'd care to explain? If I disagree with someone, I explain myself. Nicely, of course! What up?
I bet I know why he gave you the red X
Lol. Yeah, I see that now. I wasn't the only poster to suggest a V8, but he picked me out. Like I said, I wish he would've just posted why.
Heck, the OP even asked about it, and later mentioned he's a V8 guy!
If he had looked around, he would've seen that I understand the small engine approach:
I've spent enough time on this one!
Increaee the jet size on your carb and decreasde the airflow jets. FUEL=POWER!
Nitrous all the way, a 150 shot will put a 3000 lb slant 6 car in the 13's for $400
Yes if you want to burn it up. Nitrus is not cheap and its a wimpy way out!
Ignorance is bliss, Obviously you havent, reseached nitrous, a 150 shot can safely be used on cast pistons, the last Complete kit i priced was about $450, thats $3 per hp. If you find something for Less let me know, ill buy it.
I work in an high performance race engine building shop. I see first hand what nitrus does to pistons. Its a cheap way out for lack of building knowledge on how to build a naturally aspirated engine with high HP! The nitrus is cheap the set up and plumbing is not! Im not against it but there are better ways!
Every engine i have seen that was fried by nitrous was the result of not reducing total advance, wrong heat range spark plugs, and not using an air/fuel ratio gauge, and not testing and tuning. The ones i saw were 150 or less, i have no knowledge of huge shots. During WW2 the US and the German
Sucessfully used nitrous on high altitude aircraft. Some of those engines produced 1500-2000 horsepower.
Charrlie_S
Well-Known Member
I sort of agree. I only have experiance with nitrous on the slant six. I have hurt forged pistons with a 150 shot, on 225 cubes. But have also not hurt stock cast pistons on 225 shot on a 170 engine. It is a matter of the tune up.
I do agree it is a cheaper way to go quick, but not necessaraly because of a lack of ability to build NA engine. I'm strickly a low dollar racer. There is no way I can afford to build a 12 sec "A' body NA slant six car. The cost of machining alone is more then my fogger system. My car is almost 4 sec quicker on the bottle, then NA. The other niice thing about my motor is, if I do hurt a piston, it is a cheap fix. I just pull another stock piston/rod assy out of the used parts box, and put it in. Easy/peasey
Johnny Dart
Well-Known Member
The Cure
512Stroker
We are all here because we are not all there.
That's easy
Drive down hill. LOL
Charrlie_S
Well-Known Member
Yep, I'm a bottle baby.
You've heard the saying "All throttle, no bottle". mine is "All bottle, no throttle".
We run for the most part in our engines KB with a special coating on the skirt and top of the pistons for heat. You also have to set the ring gap bigger because the heat will cuae the rings to expand and seize up the pistion or destroy the cylinder walls!
Ironracer
Gearhead
Not a power increase, but diet... and if applicable to your drivetrain combo, a step up in gear. ? I know, off topic. My bad, in advance
pishta
I know I'm right....
Been said...gears. We had a 170 slant we changed out to a 225 because this car couldn't get out of its own way until the next light, and the 225 was no help. Turned out the guy had 2.54 gears out if a Cordoba! Next time I saw him he got some 3.73 gears for that rear and he laid a strip of rubber to show it off.
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Ironracer
Gearhead
Oh yeah! Big time difference! Just going from 3:23s in my 383 4spd 68 Coronet to junkyard sure grip ( 50 bucks, in the 90s) 3:55s was a massive improvement! You could jam down the interstate in 4th, and slap 3rd, Man! YEEEHAWW! the 4:56 set I put in lasted about a week, it was a fun stoplight slayer, but trying to get anywhere on 275, 75, I 4, was not a working deal.
Valleyant
Valleyant
Relatively easy things to do ; mill head for 9.25 to 1 compression ratio accounting for new headgasket, 2 barrel intake with Holley 2280 or Carter BBD, gasket match the exhaust manifold at the outlet, 2.5" downpipe to hi-flo muffler and 2.25" tailpipe, recurve the distributor. My '72 4 door Valiant with 225/auto and 2.76 gears went low 17's in the 1/4. Over all driveability was improved. My next mod would be oil control in the Pan to reduce windage.
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