killagt

iTrader: (3)

those hp is sound like my old mustang gt hp ^^

imaboa

I don't recall what the injector duty cycle was on the dyno, and didn't save any of the datalogs that I had on the dyno.

I would say that a Dyno is a pretty objective way to estimate the power of a car.

I'd do a compression and leak down test if it were my car.

- John

05HD

and you would be wrong.

imaboa

I'm not going down this road.

quik95lt1

iTrader: (7)

agreed.......last time i was on a local dyno i made 470rwhp..........the very next day i went out and ran 10.3x @132+ all day with a best of a 10.26 in a 3515lb car.......what i left out was i was on slicks with 15psi in them, 4.56's in a Dana 60, a unlocked 4800 converter and a shop that was playing games with the dyno on that specific dyno day....my car revved up slower on the dyno than it did at the track because of the excessive load they had on it.....too many variables in a dyno "number".......transmission, converter, gear ratio, tire, dyno correction and load........it goes on forever........a dyno is merely a tuning tool......if u leave with more than u showed up with ur winning.......


as for the OP....like i said start simple and check the rockers..........also make a pass with the car and see what it does.......if you cant call up a buddy with another car and go have some highway fun......get a baseline to judge from the dyno and the butt-o-meter arent always accurate lol

good luck!!!

Turnin20s

iTrader: (12)

Yeah I agree, way too many variables in a dyno setup. A friend of mine with a lightning went to 3 different dyno days and had results that were completely different. Some were 100 hp less. The shop that tuned it made 513 rwhp & 565 ftlbs. Lowest dyno day was 417 rwhp.

They also dynoed a srt charger with a procharger and exhaust, everything else was stock and it made 785 rwhp I guess slipping the dyno guy a few bucks can get you some crazy numbers

ahritchie

iTrader: (1)

A new stock timing chain and gears were installed at the same time as the cam, the injectors are stock 24lb, the fuel pump is the original stock one from 1994, as far as degreeing the cam....I don't know **** about internal engine mods or rebuilding engines which is why I paid a mechanic to assemble my motor somebody school me...I was under the impression there is only one way to install the cam? I don't see why the guy would not follow the cam card instructions but I'll ask.

Lawhead

iTrader: (14)

Thats a pretty small cam but i would be checking out the injector duty cycle that could be your issue............

Tbird232ci

iTrader: (4)

I would also check your fuel pressure. You factory pump may put out enough pressure and volume to run half decent, but not enough to support the power you are capable of.

imaboa

If you look at the dyno chart, you'll see that fuel delivery is not the issue.

If it were a pump or injector problem, it wouldnt be able to do mid 12AFRS at the top of the chart.

Dyno repeatability on forced induction, or big converter cars can be tricky. But this is a NA Manual Transmission car. Pretty easy to repeat the same power numbers.

I'm still saying there is a compression issue. Whether its static compression, or low dynamic compression caused by valves being open at the wrong time.


- John

imaboa

This motor also took a few more degrees of timing to make peak power than the LT1s typically need at WOT. Another sign pointing to a low combustion efficiency.

Puck

iTrader: (17)

My first guess was also low dynamic compression due to incorrect rocker adjustment and/or way too long pushrods.

To be THAT far off something is seriously wrong, like the intake valve not closing all the way.

MattSapp95_T/A

iTrader: (35)

that sucks!

I doubt its your injectors... my car made 391 to the tires with stock injectors and went 11.90

Matt

05HD

All we know from the dyno charts is that the car wasn't out of fuel (It shouldn't have been) and it held power pretty well out to 6500. The actual power it made is up to the variables of the dyno dynamics machine and its operator. These variables can be significant. In my experience, well over 100 hp variation. To suggest the motor is having problems without knowing the power output is absurd. All the info we have says it looks like it is running well if it is on a "low" reading DD machine.

Puck

iTrader: (17)

Any shop who has every used a dyno even once in their life won't have anywhere near 100hp variance from another shop with the same type of dyno. The only way to get that far off is with intentional tweaking like putting temp sensors on the headers and manually adjusting the correction factor.

This is a mild, all motor, M6 transmission car - not a solid roller stroker with a loose converter and S60 rear end with misleading dyno results. Of course all dyno's will show some variance - even just pulling a car off the rollers and putting it back in will change the numbers a hair - but his dyno results should be fairly repeatable.

Unless the dyno is broken the motor is most definitely having problems - with bolt-ons and a cam it is literally putting down LESS power then a stock M6 should put down.

ahritchie

iTrader: (1)

I agree it's definitely down on power; it's not just the dyno reading low, I've got my mostly stock 99 Firehawk 6spd to compare it to and it is no comparison past 4000 RPM....LS1 kills it. I should have an update on WTF is going on this weekend or Monday night; going to re-adjust valves/rockers and do a leak down test...and while I'm at it replacing the E3 spark plugs with NKG TR55's...I've read the E3's aren't worth a damn. Hopefully the culprit is not the bottom end.

SS RRR

iTrader: (2)

Dyno Dynamics is one of the most inaccurate dynos ever made. Seems the most questionable numbers produced come from DD dynos. I've always wondered how it is an engine's true power can be measured on rollers that produce no load...
As suggested, take it to the track.

defaultexistence

iTrader: (11)

Spray it!

05HD

Sounds like you have never used a DD dyno. If we were talking exclusively about dynojets with the latest software and uncorrected numbers, I would agree with you. Here is a random example from my personal experience on a Mustang dyno, I tuned a 3650 lb 6 speed car that made "680 rwhp". I was skeptical because my datalogs indicated it was using 90% duty cycle on 6 1200cc injectors and fuel pressure wasn't dropping under load. The butt dyno after the chassis dyno was inconclusive because we couldn't get the car to hook on the street that night. Sure enough, it trapped 147 the next day at the track. That is roughly 850 hp. So, the guy didn't get a awesome sheet to hang on his wall and brag about but his car was just as fast as he was looking for.

Also, power can get lost in a 6 speed driveline just as easily as an automatic one, just not intentionally.

So, I say again, we need some other indicator of how much power the engine is actually making before we condemn it.

Puck

iTrader: (17)

I understand the differnces between dynos, but there is a huge difference between an 850rwhp monster and what is basically a hotcammed stock M6 LT1. He even said a bolt on LT1 made more power then him on the same dyno.