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Discussion Starter #1
This might sound like a very strange question but it is satisfy race rules.

A stock 2V makes about 260hp/310tq to the wheels with long tubes, and a 4V with long tubes makes about 260/260

So as not to be down on torque, I have a couple of options.

1. swap out the entire engine.
2. swap out the heads to a 2V

In my case the compression ratio shouldn't change much when swapping heads, but I'm curious if there is a simpler way to achieve this?

different intake? throttle body?

Thank you
 

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you numbers are far off

a stock 2v makes 200rwhp maybe 210 with long tubes

a stock 4v makes 240rwhp and 250 with long tubes.

see my reply in your sister thread
 

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Discussion Starter #3
Thank you for the reply!

however, something is off.
The Camari Mustang Challenge guys dyno their cars and determine the power to weight ratio...

the formula they came up with is bone stock, long tube headers, no tuning gets between 250-260hp and 300-317tq.
Let me know if you think something doesnt jive...

you numbers are far off

a stock 2v makes 200rwhp maybe 210 with long tubes

a stock 4v makes 240rwhp and 250 with long tubes.

see my reply in your sister thread
 

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HP = Torque * RPM \ 5252
Therefore you cannot increase torque without increasing HP
 

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HP = Torque * RPM \ 5252
Therefore you cannot increase torque without increasing HP
True. but I think you miss his point/meaning. You can increase low end torque, which...yes... will increase the corresponding hp at that low end range, but without exceeding the hp limit over all. I think that is the OP's goal.

If you could gain say 40 ft-lbs at 3000 rpm that would be substantial AND you would not run afoul of the hp limits.
 

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True. but I think you miss his point/meaning. You can increase low end torque, which...yes... will increase the corresponding hp at that low end range, but without exceeding the hp limit over all. I think that is the OP's goal.

If you could gain say 40 ft-lbs at 3000 rpm that would be substantial AND you would not run afoul of the hp limits.
This.

If your race series has a horsepower limit but not a torque limit, and you want to stay under 270hp, and you make that 270hp at 2500rpm and put down 568ft-lb. ;)
 

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Would a 40 shot of nitrous that turns on at 2.5k and off at 4.5k be out of the question? :cool:
 

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Wouldn’t a cam change accomplish this? opposite of what many want of higher HP at higher rpms.

You want to push the peaks lower in rpms correct?
 

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Discussion Starter #12
Yes, but you can move the curve down.
A 500 hp diesel that peakes at 1500 rpm, makes 1000 lb of torque, but a 500 hp 4 banger that peakes at 8000 rpm will make 300 lb/ft of torque.

So yes, you can make more tq without increasing hp.


HP = Torque * RPM \ 5252
Therefore you cannot increase torque without increasing HP
 

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Discussion Starter #13
Correct!

In my case, I have both: hp and tq limit which was figured out by dynoing a bunch of 2V cars and GM cars and taking an average.

The general consensus is that a sohc with headers dynoes at 260/310ish, and thats what they have set that series’ power goals to be.

Nobody runs a dohc car because a) they are less common and b) they make less tq

So I am curious as to what is the most easy/common way to do this.



This.

If your race series has a horsepower limit but not a torque limit, and you want to stay under 270hp, and you make that 270hp at 2500rpm and put down 568ft-lb. ;)
 

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Discussion Starter #15
I want to keep the hp where its at, but move peaks lower.

cams should do this, and maybe a smaller throttle body, longer run er intake, etc.


Wouldn’t a cam change accomplish this? opposite of what many want of higher HP at higher rpms.

You want to push the peaks lower in rpms correct?
 

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