ok so Ive been wanting to see what kind of power Im getting out of my car and today I finally took it to a dyno shop I was SOOO excited to see numbers in the 300 range for horse power and torque BUT NOOOOO after the first pull we thought something was wrong so we didnt pay attention to the numbers but the second pull surprised the daylights out of me we ran it all the way to 8500 rpms and it was still climbing with out floating any valves I was shocked it even revved that high in the first place. then he told me the peak power hit at 6500 rpms and there was nothing left after 7000. I was shocked I was very happy to hear it was gaining power up that high in the rpms. now the bad news remember I said we thought something went wrong on the first pull? well NOPE after all that I got a whopping 98 horse power. ( I was thinking somewhere in the 350 range) he told me theres not nearly enough fuel going through the motor. (two jet sizes too small) here I thought it was loading up. its actually starving for fuel. I was also told that the drivers side of the motor is virtually dead. he couldnt even get a reading of carbons from the drivers side and the passenger side is barely reading the first pass we used a sniffer in the header and thought well maybe its not getting enough gas to it since the header has such a big opening so we used a vacuum pump for smog on the second pass and still way too low so this weekend Ill be tearing into my motor and figuring out whats not right Im going to start with a compression and timing check. after that its off to checking the rockers making sure theyre not too tight or too loose it was fun until I heard the 98 horse reading he figured I should be around 350-400 horses with my setup
What is in your engine? It has to be a solid lifter cam to do 8500, and that would be with good springs. We turned Yates headed motors 9200 with no problem but they were solid roller cam, shaft rocker, billet crank, Carrillo rods, dry sump engines with titanium valve trains and killer springs. We're talking the best of the best available. We never turned it that hard on a dyno, no reason to. Why would you turn the engine that high on a dyno pull when it wasn't making any power up there? You are risking serious damage. SPark
98 hp ,wow thats hard to believe. Just think what it will be like when you find out the problem is if you can fix it. I always have wanted to put mine on the dyno, I figure by track times, weight etc. that I am around 300 - 325 hp but wouldnt be surprised if it was less. I will only spin mine up to 6,500 I wouldnt want to even try 8,500
just had my supercharged '03 mach 1 dyno'd monday (562hp/501tq) and was disapointed that it didn't hit 600....after reading this i guess it wouldve been worse lol
my engine has inexpensive parts in it as far as I know. I know its bored 40 over with I believe forged pistons. I put an extreme energy comp cam in it. I can never remember the duration but the lift is 512 and the rockers are stocks I know for sure. the cam came in a kit with cam springs and lifters. I know the push rods in the car were really new when I took them out and what brand or material theyre made of I dont know. when I took the push rods out they werent the usual silver metal color they were almost a brass color gold/yellow they were straight and didnt have any flat spots on them so I reused them. why rev the engine so high? well I had no idea how high it was. I was just operating the gas until someone said stop. I couldnt see what the computer was saying and I dont have a rpm gauge in my car yet I know the whole building was shaking my vacuum is way too low so I have to get a compression tester tomorrow my vacuum isnt even at 7 inches at idle. at 6850 rpms I had 29.22 hg of vacuum what is that HG?
HG is a measure of vacuum, it's inches of mercury in a monometer. I doubt you were actually turning a stock pushrod, stock rocker engine with a hydraulic cam that high in the RPM range. My guess is the gold color on the pushrods is oil cooked on common steel, stock type pushrods, nothing exotic. A cam with .512 lift in an Extreme Energy profile (hydraulic roller?) would fall on it's face around 5500RPM if I remember correctly, it's a pretty mild cam by most standards. That 5500 would need the heads, intake, carb and exhaust to be correct to reach even that low limit. Being 2 points off on jets is minor. It might effect a few HP but probably less than a dozen. 2 jet sizes isn't much of a deal to correct. Gains would be minimal. I think somebody is pulling your chain on the RPM you turned. Stock parts will give up long before that. I've had open dirt late model engines on the dyno all day long playing with different carbs, headers , intakes, valve settings, timing, etc. 7500 sounds like a lot inside a building. That was on a standard dyno, not a chassis dyno. Sounds like the engine is on it's last legs. Look at your printouts and let's find your problems. What was the BSFC? How about the AFR? Did you have a hat on it to see what CFM the engine was pulling at the carb? How about probes for EGT? Did your dyno operator suggest any changes besides 2 jet sizes? JMO, SPark
a dyno has humbled a lot of people... seems everyones... guess is their car is...325-400 RWHP until they do a pull...then the dyno is wrong or the guy doesn't know how to operate it. as for the 8500, I have a pull sheet with 10800 RPM @98 MPH on it...302 punched to a 308... that was a hundred bucks well spent...
I would bet the dyno was screwed up, and spitting out all kinds of incorrect info. No way on the 8500, no way on the 98 hp. Way less, and way more.
Agreed... If it did happen, their'd be a lot of pieces to prove it... I think you need to find another dyno shop...
