have you done a tune up and atleast checked the plugs? going lean isn't a good indication. 13.0 is the highest you wanna go on a N/A motor. on my 87 with a handful of mods pulled a 12.9 across the board. at idle and upto say 2000 rpm the car should run in a lean state and gradually increases fuel pressure.

here are my dyno sheet and AF ratio sheet.





i had problems when i dynoed the car. i just added long tube headers and went to dyno it and they hooked me right up so i didn't cool down. i made the pull at 220+ water temp. then the EGR tube i had fabbed up for a temporary blew out on the first and only pull so i can't tell you how much HP i lost due to no back pressure on cylinder #8. i do know when i run at 130-140 at stage and anything above 180+ is 2+ tenths in the 1/4 mile from testing the car from a cool run and hotlapping right afterwards. this equals 20+ rhwp.

my mods at the time were very little.

K&N open air box, MAF descreened, TB Bypassed, 160* T-Stat, Accel Super Coil, 12* degree advance timing, plugs gapped at .047 Indexed, TPiS Long Tube Headers, !Air, !EGR, and dumps off the rear Y pipe. Hayden Tranny cooler. Stock 1600 rpm stall, 2.59 rear gear

i think the car could of pulled in the 260-270 rwhp range and 370+ rwtq if all the conditions were right.

if you don't have any other mods do the cheap and free mods. they DO help and i think your car will pull in the 220 rwhp range and 320 rwtq.

with your cam the stock tune should work just fine. your cam isn't much bigger than what was in it. i know guys running 11.7's on stock chips.

 

double post sorry

 

Interesting to see the two different dyno graphs. If the first 3000 rpms were not on mine they would similar in shape (except for the peak readings of course). I have not had a tune up done...that is probably #1 on the list. I have all the basic add ons: K&N with cut lid, TB airfoil, upgraded catback system....all the stuff that has debatable performance impact...but low cost and easy installation.

I was also wondering if the A/F ratio change might be due to the car basically reaching a point of diminishing return on the air flow through the intake. Since it is a ratio and not an absolute value of air or fuel. At low rpms plenty of air, but as the engine rpms climb, the airflow doesnt keep up with the fuel and it gets richer on the graph? Either way I am reading in the posts that 14's is too high. Thanks again

 

the ecm controls the fuel injector pulls. more air that pulls across the MAF sensor the more fuel the computer puts to the car. at idle all cars run lean. the burn is smaller due to extra fuel and stress is down on the motor. once the rpms come up so does the fuel pressure.

 

The new versions of the Mustangs all have a minimum of 2 tach pick ups. The one that every one shoud have is a iductive, then the optical and lastly the low current probe. I am in the process of procurring a foruth option. And that is one that plugs into the OBD2 port and extracts the information direct form the PCM via the serial data buss. This wll be the best as I won't have to remove plug wires or to have to dig around lokoing for the set timing connector again.

 

Do these dynos have a raw timing listing, of the
rotating drum?
Knowing that timing, plus the rotational inertia
of the drum, is enough to calculate power.

When I get an engine tested on a chassis dyno,
I want to know about the engine, it is only
in a chassis for convienece.
I want to know, how much power goes to the ground.
I --> don't <-- want to know about,
aero drag, driver skill, car weight, their estimate of
driveline loss, 1/4 mile ET estimates, etc.

No offense, but I don't trust anyone.
When these people, ask for / or offer, more info
than they need, the warning should go up.

 

It maybe in the software somewhere. I would have to look. Irregardless even if you knew that, one would still have to calculate drive train losses into the equation and other frictional losses as well. The best way for true power is to get the engine on a engine dyne before its in the chassis. Local costs around here to get your engine on a dyne is around $650 for the first 1 to 2 hours which includes setup.

 

tj',
the story I get is, these machine offer there
numbers as 'rear wheel horsepower'.
If you loose 50 Hp in your tranny,
we'll thats unfortunate, but why are you trying
to estimate that ... when ...

you have a direct indication of 'rear wheel HP'
you report 'rear wheel HP'.

note, just for the record, I would consider
the following corrections as semi-legit...
temp-baro
drum inertia - driveline inertia takeover factor
correction for tire loss... extra 'scrunch caused
by drum radius'

 

i take it your talking to me? if so just to let you know alittle bit about myself i've been turning wrenches for fun and on race cars now for over 16 years. i've worked on 9 second street cars to 5 second top alcohol dragsters. you can calculate all you want but the bottom line is if you don't know the effects of this and that then you can't calculate nothing! so now all the calculations are irrelevent and it comes down to common sense and knowledge of engine theory, management, along with weather factors. i can tell you exactly what my car will run at 130 degrees water temp and all the way upto 220+ water temp in the 1/4 mile before i run the car by factoring in the DA. so yes i think i can legitematly guestimate with a very close outcome of what the car will do. when you race ALOT and are willing to look outside the box of calculations these things just come too you