New dyno results.

[Eos]

Well I got the car dyno'd again. I didn't get my hopes up for very high numbers. Although my dad was still highly optomistic. So first we did a dyno in 3rd gear because thats where we made the highest power the first time. It made 153 hp and 227 tq. That is with the cam swap. Compared to 2 years ago when it made 142 hp and 236 torque in a 3rd gear run. Then we did it in 4th gear. This time it made 153 hp and 233 torque,And my car did 124 mph according to the dyno. As compared to 2 years ago 4th gear pull at 135 hp and 240 torque. Soo I gained 18 hp to the rear wheels from the cam swap and lost only 3lbs of torque. And now the hp is staying about even between 3rd and 4th gear runs. So I guess thats good news... but IT'S NOT GOOD ENOUGH! So I guess I'll be doing headers when I save up a lil money. Which I'm horrible at doing.. lol I am a girl and I do love clothes... Anyway! I hope to get them by this spring when my dad plans to do all the rearend work on the car. How much hp do you think headers will unlock? Because 153/233 just isn't going to cut it!

 

[Addicted_2_II]

EOS,
You can't think of it in just horsepower, you have to look at what you want to do with the car! Right off, I am not sure Headers are a good next step. Others around here may be better at suggestions than I am but I think Headers will be a lot of trouble and $ for not all that much gain!

I had to pretty much lift my engine out of the car just to set my headers in plus my stock exhaust would not have matched up with the header collectors. So as you can see, it would probably not be as easy as just buying headers.

Do you want more acceleration? Or more top end? Let us know what you "WANT" out of the car and maybe we can help!

For example, if you just want more low-end, a new set of gears would probably do much more than adding headers... (My Opinion)

Also, if you are running stock heads, headers will even provide less improvement over the stock exhaust manifolds than if you had aftermarket heads.

I ran my numbers from my 1/4 mile run and even with everything I have done to my engine, I am only putting out about 233 HP at the rear wheels! I know my main bottle neck are my heads with the small valves!

I hope I have been of some assistance,
Chad

 

[Blue Thunder]

Especially after the performance cam swap, headers will give you quite a bit of power over the stock manifolds. (But undoubtedly your motor needs its fuel and timing curves calibrated, also.)
When you lose overall torque after moving to a more aggressive camshaft, it means something is restricting the airflow at higher rpm; stock manifolds, heads, probably both are responsible. With a larger camshaft, if the other components are up to the task, and the carb and distributor are set up correctly, you should gain hp and the peak torque will move up in the RPM range, and though low end torque will be lower, peak torque will increase.
Instead of just changing to headers, you should upgrade the heads at the same time, so start saving up.

 

[Power Surge]

Megan, do you have the dyno sheet? Did they measure A/F ratio? Was this the same place that dynoed it the first time? If so, did they give you a printout with the before and after on the same graph? I'd like to see how the curves compare to each other. You might have lower peak torque, but more torque in other areas of the graph, which will equal a faster vehicle.

As for the "gear", you always want to dyno in 1:1. So with your 5 speed, that would be 4th gear. That's the only numbers you need to be concerned with.

 

[jasonh_86]

EOS,

Nice numbers. Can't wait to see the numbers with headers, intake and some heads

I wish my a/f wasnt so high Maybe I could put better numbers down then

 

[Eos]

I got the dyno sheet here. I guess I'll be doing headers, they will offer the gains I need for right now. I simply DO NOT have the money to do heads. I have car payments and insurance for my new car. I just want my car to make 200 hp right now instead of an embarressing 153. Oh and he said my air/fuel was fine. And my car has had a recent tune.
View attachment 492259

 

[jasonh_86]

I know how you feel about not havin the money for parts like that. I wish I had the money for headers and heads, but i've got other stuff I need to take care of.

That'll be nice to see those numbers with heads and headers tho, after you get all the money and everything later on down the road.. I bet it'll be runnin real good then

 

[Eos]

I know how you feel about not havin the money for parts like that. I wish I had the money for headers and heads, but i've got other stuff I need to take care of.

That'll be nice to see those numbers with heads and headers tho, after you get all the money and everything later on down the road.. I bet it'll be runnin real good then

Well right now I'm just worried about headers, intake, gears t lock and traction! Heads might be awhile. I consider them the ultimate modification next to the 347... hehe Someday but not anytime soon.

 

[Power Surge]

Megan, great dyno sheet, all the info I wanted to see...

Look at your before and after torque. That's the red line and blue line that start at the top left of the page. See how the blue line (your before) is only higher at the very beginning? That's why you have higher peak torque. The rest of the rpm band has tons more hp and torque than before, so that's great. I am really impressed with the power gain you got from the cam alone.

Now notice where the hp line starts to even out around 4k, and then drop off at about 4500. That's your exhaust restriction. The headers will help that some for sure, even before head work.

As for your air/fuel, it's actually very rich. That's costing you power. See the red referance line that goes across at 13.0? THAT'S where your A/F should be, as naturally asperated cars make optinum power at about 13.0. You've probably got another 10-15 rwhp in the carb tuning alone.

 

[Gael]

Yeah, you're running way too rich.

Here's a pic of all of my runs when I dynoed a while back.

I'd definately tune your carb, that's hurting you.

 

[welder4956]

Megan, great dyno sheet, all the info I wanted to see...


As for your air/fuel, it's actually very rich. That's costing you power. See the red referance line that goes across at 13.0? THAT'S where your A/F should be, as naturally asperated cars make optinum power at about 13.0. You've probably got another 10-15 rwhp in the carb tuning alone.

Sal,

Help me understand air/fuel ratio better. If A/F is 13.0, does that mean 13.0 units of air volume to 1.0 units of fuel volume? I guess that makes sense. If it drops to 11.0, that means there is less air for the same volume of fuel, so it is running rich. If A/F were running above 13.0, would that be an indication of a fuel supply problem (if tuning the carb didn't bring it down)?

 

[Power Surge]

Sal,

Help me understand air/fuel ratio better. If A/F is 13.0, does that mean 13.0 units of air volume to 1.0 units of fuel volume? I guess that makes sense. If it drops to 11.0, that means there is less air for the same volume of fuel, so it is running rich. If A/F were running above 13.0, would that be an indication of a fuel supply problem (if tuning the carb didn't bring it down)?

You are correct. The higher the number, the leaner the mix. For NA cars, about 13.0 is optimum for pump gas, 13.5 for race fuel. Power adder cars (blower, turbo, nitrous) are run about 11.8 for pump gas and mid 12s on race fuel. Megan's car goes real rich, even too rich for a power adder car (which hers isn't).

An actual fuel supply problem usually shows up as the A/F curve ramping lean as the rpms go up. We see that a lot on the EFI cars, when either the MAF pegs, or you run out of pump or injector.

 

[Eos]

Wow thanks for the info Sal. I'll see about getting the carb tuned up again. We just had it tuned so I thought it was alright. I guess maybe I should let them check out my dyno sheet and see about getting it retuned. I know it was running too rich before the tune. I can still kinda smell gas in the car too. Well anyway thanks for the insight on that Sal.

 

[Wart]

Sal,

Help me understand air/fuel ratio better. If A/F is 13.0, does that mean 13.0 units of air volume to 1.0 units of fuel volume? ....

Not by volume, by mass.

13 kg air to 1 kg fuel.

Or it can be thought of as 'weight' but that's not quite proper.

In 'weight' it would be 13 pounds air* to 1 pound of fuel.

13 gallons of air to 1 gallon of fuel (gallon being volume) would be a bit rich.

{edit}*changed from gasoline to air.{/edit}

 

[Vince]

Wow thanks for the info Sal. I'll see about getting the carb tuned up again. We just had it tuned so I thought it was alright. I guess maybe I should let them check out my dyno sheet and see about getting it retuned. I know it was running too rich before the tune. I can still kinda smell gas in the car too. Well anyway thanks for the insight on that Sal.

Chances are when they tuned the carb all they did was adjust the idle mixture. It may need different jets, rods (Edelbrock carbs) and/or power valve (Holley carbs).

 

[Eos]

Chances are when they tuned the carb all they did was adjust the idle mixture. It may need different jets, rods (Edelbrock carbs) and/or power valve (Holley carbs).

Yeah the dyno guy mentioned doing something to the jets or secondaries or something. I don't know it confuses me.

 

[Blue Thunder]

See if the dyno guys can jet the carb and adjust the distributor advance curve while the car is on the machine for optimum power.

 

[joeythesaint]

Not by volume, by mass.

13 kg air to 1 kg fuel.

Or it can be thought of as 'weight' but that's not quite proper.

In 'weight' it would be 13 pounds gasoline to 1 pound of fuel.

13 gallons of air to 1 gallon of fuel (gallon being volume) would be a bit rich.

My brain just exploded.

 

[Wart]

OOPS!!

the line In 'weight' it would be 13 pounds gasoline to 1 pound of fuel.

Should read:

In 'weight' it would be 13 pounds air to 1 pound of fuel.

 

[Cool Wheels]

That's interesting. For those us that bought the automechanics for dummies book, what diagnostic tool would enable one to adjust to those exact specs? Or because of the RPM curve would that only be something you could do in a shop during a dyno test? And do you have to convert weight to mass by removing the gravitational coefficient?

Megan: Just curious about the effect of the cam on your gas mileage? And your signature just kills me - is that Deep Thoughts by Jack Handy?

Later edit: I just realized that in a ratio type calculation weight would give you the same result as mass (effect of gravity would be divided out on both sides of the equation) so you could use either. That's just what everyone was dying to know right?!