CHRISPY

It is a combination of factors that can't be corrected by the weather station on the dyno.

Chris

verbs

what he said!

verbs

Like me DA was almost 3000ft so I'm not too worried....I figure the power was there with a 36xx raceweight.

mikey

iTrader: (6)

Correct. I am seeing it here every day when I am tuning these "budget" packages. Expectations run high and disappointment is ususally the norm after the dyno session. Remember, you get exactly what you pay for (most of the time)

Country Boy

iTrader: (24)

You guys are funny..... I guess all the dyos lie? The good times just means you can put the power to the ground and have the right suspension setup.

In the summer the air is alot hotter and moe humid and that means less power, Everyone knows the colder the air, the better the HP. The dyno can sorta correct for the temps, but not for the hot, wet air that the motor is taking in.

SPANKY LS1

iTrader: (24)

I think the biggest reason for "low" dyno numbers (we'll call them "real" numbers for the sake of this discussion) are the "freak" cars. People see Gomers car dyno 47X/42X with PP heads and FMS cam, go out, buy the same package, and hit 41X/37X, and are disappointed. People see Damians car dyno 47X/42X with TEA heads and FMS cam, go out, buy the same package, and hit 41X/37X, and are disappointed. People see JRods car dyno 49X/44X with AS heads and LG cam, go out, buy the same package, and hit 41X/37X, and are disappointed. People see BSPZ28s car dyno 49X/44X with Cartek heads and cam, go out, buy the same package, and hit 41X/37X, and are disappointed. See a pattern? IMO, the "real" numbers are the 41X-43X rwhp numbers. The 450+ cars are freaks, the exception rather than the norm, IMO. Some are using signifigant dyno "tricks", such as no belt, cutout, tire pressure, etc. Also, dynos can be manipulated to sell parts. Sure, 1/4 ETs and MPH is a more viable way to determine power that a CAR actually puts down, but big dyno numbers sell. How many sets of heads did Gomers car sell for PP? Damians for TEA? JRods for AS? BSPZ28 for Cartek?

We'll leave the subject of "ringer" heads alone for this thread....

DISCLAIMER: This thread is in no way aimed at Gomer, Damian, BSPZ28, or JRod, and is meant to take nothing away from their cars, setups, or accomplishments, just using them as examples.

Shawn

Tranzor

I don't think low dyno numbers are a big problem, really... gotta look at each individual car. Obviously if your car dynoed on the low end of the spectrum when it was stock, or when it had bolt-ons, then it will dyno lower when you have cam, heads, etc. too. With everything in my sig I only dynoed 336 rwhp and 337 rwtq... I've seen people who claim to have completely stock cars dyno that. So obviously no matter what size cam I put in my car, I'd be hard pressed to get to 400rwhp without getting heads. But my car runs well at the track, and has low 12 second passes in it with a better driver and clutch, and with no weight reduction... so the fact that my car isn't a dyno queen doesn't bother me in the least, because it does what it's supposed to do... it goes fast.

Also, you have to look at the shops/areas they're dynoing in too... it's the same for track numbers. Just because someone is able to run a 12.2 with the exact same mods as me at their track doesn't mean I can go out to my track and run the same numbers. Just because someone dynoes 20 rwhp higher than I did with the same mods on their local dyno doesn't mean I can go to mine and pull off the same thing.

JS

iTrader: (4)

I'd have to agree with Spanky...
Its all smoke and mirrors and then there's everyone else.

01tam6

iTrader: (1)

I was pretty happy with my numbers from this week dynoed 356rwhp and 372.3ftlbs with 90.7 degree temperature bolt-ons only.

CamaroCain

iTrader: (1)

Like mentioned above somewhat....dont look at what a Heads and Cam car dynos, look at what it picks up from the package. Our S2 heads and HUGE cam only put down 409rwhp on the dyno, BUT it was up from 310rwhp from the bolt on numbers it was seeing on the exact same dyno. A pick up of 99 rwhp from Heads and cam(nothing else changed at all).
We wont even discuss track numbers, because also as mentioned above, big stall and gears(which will also make numbers seem low), its in the overall setup. Since the discussion was on the dyno, I just believe it is better to see gains than compare with everyone else's dynos.

CHRISPY

I think it would be great if shops worked with customers on complete packages.

ie: I want the car setup to run a 10.90 index with heads and cam.

or

I want emissions legal and 11.50@117mph with a six speed in summer heat.

The guys that run well dial in the entire combination. The heads/cam tuning combo is really just one factor in the bigger picture.

Take for example my combo. It is not nearly ideal for the track at this point.

I run 11.40's@123.8mph in ~2500DAs on a street legal tire granny shifting at 6000rpm (M&H)

With proper gearing (4.30), slicks (28x10) and powershifting the car would run 10.80s@126-127 in similar conditions.

A change from ~124 to 127mph is ~40-50RWHP increase on the dyno if looking at strictly engine output numbers.

Thing is that change from 124-127 is easy to achieve with proper gearing/shifting/tire/chassis setup.

That is what a lot of people have problems grasping.

95z6spd

iTrader: (1)

My dads car put down 404rwhp/382 rwt through cats. This was with PP LS6 style heads and a 226/.584/114 XE-R cam. A4/3500 stall/ 3.73 car. A 12 bolt was just installed and have about 200 miles to go till its fully broken in. If the numbers are right it should run mid 11's in the heat as long as we get a decent hook. I think alot of the numbers have to do with the exact combo of the setup along with the condition of the motor. If the combo is thought out right and installed correctly and tuned correctly on a good sound motor, it should make power..Now E/T's are a different story. Curb weight/suspension/tire/weather/ and driver are all contributing factors for a good E/T.....

JS

iTrader: (4)

I'd like Mikey to redyno the car after the 12-bolt was installed.It would be interesting to see how or if it lost anything,I know I lost 11RW but every car is different.

I like the 231-237 cam w/pp ls6 heads.Thats an impressive package,I saw it running 11.50's@119 in a vette during the rent a track we had last week in the heat.

Country Boy

iTrader: (24)

I wouldnt say smoke and mirrors... in the summer weather (read 90*s and 80% humidity) I put down 440 RWHP with my setup (LG cam and AS heads) on a so-so tune on a new motor........

Linear Velocity

iTrader: (1)

Again I agree with Country boy, that hot/humid weather is a cop out. You guys are all like Milli Vanilli, "Blame it on the Rain."

Mirek

I agree w/ Spanky. Why don't tuners use Mustang dynos if they are supposed to be much better for "tuning" It seems the easy answer is the "much" higher dynojet hp (sales) numbers.
Both tuners here do not manufacture parts and they both use mustangs.
I don't know I'm just asking.

kumar75150

I agree

people with cars setup for the track who keep saying "take it to the track" have lowered the bar on heads/cam numbers IMO (this excludes auto cars for the most part)

TexMax

I gotta agree with the track times are more important than dyno numbers opinion. I don't care how much hp or torque my car has, as long as it goes fast. That's why I'm putting a 4000 rpm stall on it that'll probly rob 10-15 rwhp; screw power, I want speed. I wanna beat my dad's viper. There's a whole new kind of snake for ya.

Linear Velocity

iTrader: (1)

But to go fast at the track you don't necessarily need high HP numbers. Like said before good track times are more indicative of a complete setup. Suspension, gearing, weight, track prep, DA are all thing other than HP that will help you run fast at the track. "take it to the track" also doesn't apply to everyone because not everyone here is a drag racer; and your convertor would actually hurt you in a race on the street from a roll vs a viper because they rob top end power

Ben R

I saw a 6 spd LS1 trap 122.5 MPH and only put down 410 RWHP. There are a few things that can affect MPH besides power output.