Hi guys my car made 327rwhp at 5500rpm and 334tq at 3800rpm. I have 3.73 and frame is all tied in also have 2800stall converter. I was wondering if anyone had anything close to see what they ran. I already did the quarter mile simulation. Anyone care to guess ???

 

Estimating at a 3300 pound race weight, you should do low 13's. A guess however is just a guess. Any number of things can affect a run. If you really want to know what it will run, you need to get on a track. Don't be disappointed if it's much slower than you expected.

 

You are absloutly right. I would guess around 12.50 car ways about 3750. Mid 13 teens I would think would probably be in the mid 200's don't ya think.
Hay you run in the 9's right what is your vehicle weight and curios about what heads and compression you are running. If I had to guess your hp with out know these I would have to say somwhere in between 750 to 800 cranks HP. With a slightly heavy car?

 

I'd say at 3750lbs (yikes!) you'd run in the 12.90-13.0's with that kind of power... Maybe better if the car is setup perfect and track conditions are right (2 things that rarely happen together).

 

I think your close car ran before 12.60 106 mph with vortec s trim 7lbs. sportsmans heads ported on the exh mostly. Hay what is your weight ? Because your car is flying?

 

540 BBC with Canfield 310 aluminum heads. Compression ratio is around 14.2:1 running on alcohol. Estimated corrected HP is around 760 based on the power to weight ratio formula. I never had it on a dyno. Race weight is under 3100 pounds. That's car, fuel, me etc sitting on the starting line.

Your weight of 3750 is terrible. A typical third gen should be about 3500 pounds. At 3750, I'll change my guess to very low 14's with only 327 HP to play with. Maybe a high 13 if you're lucky.

 

Hey remember that is rear wheel horsepower not crankshaft horsepower. At the crank was about 400hp and 410lbs of tq.

 

Power that gets to the wheels is what finally moves the car. I still stand at low 14's.

 

Okay if you are guessing that a car that went 14.80 stock with about 235 crankshaft horsepower, Now has 400 crankshaft horsepower and only picks up 2 -3 tenths 14.20's. Well then that is your guess sir! Its hard to beleive though that making another 165hp at the crankshaft that I will only gain a .5 second right?

 

Crankshaft HP is only good for engine dyno tuning. If you say you're getting 327 HP to the wheels and the race weight is 3750, I say you're only going to do low 14s.

HP goes up exponentially as ET drops. A 15 second car gaining an extra 100hp from something like a NOS system may drop a full second in ET. A 13 second car getting that same extra 100hp "might" drop only 1/2 second. An extra 100 HP in my car might get me another 1/4 second.

If you run less than 14.0 then either your race weight is far less than you think, you're getting more HP to the wheels or you're at the maximum HP level all the way down the track which isn't going to be very likely.

 

Well I am a little confused of the exponential thing, But if you think your right than thats what makes forums so good the different opinions make it interesting. Remeber I have already ran the car on the chassis dyno and also already did the 1/4 simulation on the dyno. Are really sure 14. teens. The car was scaled with me in it @3750. Guess what it ran ? you have to get closer than that. Think about stock c-5 with 345hp at crankshaft that run 12.70ish all day long with a good driven and bfg drag radials. Come one give it another shot. This is what makes the forums fun!

 

ok. So you're looking at dyno hp, not real world hp. Best guess, 13.5 unless you're racing in winter conditions. What was the dyno correction factor for that day?

A dyno simulation doesn't take into effect wind, air resistance, tire resistance, how accurate your shift points are, what the current air conditions are etc.

Dyno HP is corrected to perfect sea level conditions so all dyno results can be compared to each other no matter where they were done. Your engine will never make that much power in real world conditions because of air temperature, barometric pressure humidity and the altitude you race at.

What type of dyno? Mustang dynos can give wild numbers.

A stock C5 doesn't weigh 3700+ pounds either.

 

Okay here we go a chassis dyno that is designed to simulate load during quarter mile blasts uses an initeria factor. The interia factor is calculated based of a several things here is the two main user inputs: vehicle weight, and hp a 50mph. These two are the user inputs on a mustang dyno. These facts are given from the factory for any vehicle the higher the @ 50mph hp number the great drag coefficient. The mustang dyno comes with a vehicle look up table for all year vehicles this info is produced from all the vehicle companies. Second is the weight. The mustang dyno software then accurately simulates load to the vehicle as if it where doing the entire quater mile. The dyno simulates load using an eddy current absorber. This has proven to be highly acuurate based on years of testing and theory. I am keeping this as simple as possible not to bor you but to share with you what I know.
Mustang dyno co. guarantees accuracy with .2

OKay next dyno horsepower is never corrected to perfect sea-level conditions. If you can understand the purpose of a correction factor then you would understand why you are wrong by saying that.
The mustand dyno has an on board weather station that constantly measures: air temperature, humidty, and baro.
The calculation is then made based off these number as corrected.
Now think of this, take a good winter day when condtions are ideal, you would see typically like 1.009 correction fator.
You know when your car typically runs best, based on the pics of your car I am sure you pic up a couple of tenths when air is good right?
Okay now take a hot summer day real humid air is horrible ! A typical correction factor would be say 1.074 or even 1.099.
Now you no your car will run slower in the heat I agree with that, but what you have to think of is if you want to measure horsepower on a winter day and then same test on a summer day you need a correction factor. Yes the car will slow down in the summer no kidding however, but when you dyno the car it will produce the same numbers on that hot day as it did on that perfect winter day. Because of the correction factor simply to measure horsepower. Look at the numbers perfect day 1.009 -Bad day 1.099
The only other number produced is uncorrected.
Remember also no dyno measure HP all dyno's with a load sensing device, eddy current absorber etc. measure TQ then the math is derived. Other dynos simply do acceleration times any look up hp table.
I have seen about 6 time slips in hand and 5 passes on the dyno with in .2 doing quarter mile simulation.

 

I race at altitude. I can only wish I could get a correction factor that good. Last October on our last race of the season, the correction factor was 1.13. An ugly day last July, the correction factor was 1.15. My engine loses about 100 hp just because of the air and altitude but I tune accordingly. Because I run alcohol fuel, I need a big change in the air before performance is affected.

I don't race dynos. I race 1/4 mile dragstrips. You can believe all you want about your dyno results but if want to really know what your car runs, get on a dragstrip. There's a lot more factors on the dragstrip that a dyno can not simulate.

 

for me. i think that the dyno only gives you a rough idea what the car can do.
but like stephen said. take it to the strip and you can really tell what your can do.
i dont think i would ever use a dyno to tell me how fast my car could go in the 1/4 mile. i wouldjust go to the strip and find out there. most accrate then a dyno would.
i would use a dyno to see how much hp im putting to the wheels and what not. thats pretty much all i would use a dyno for. and tune my engine to get the most power out of it as i can depending on weather conditions.

 

JFWIW - my 2000 with just bolt ons, 3500 stall, M/T DR's ran 12.20's @ mid 111 MPH traps... dyno'd 329HP/341TQ the very next day. The car was full weight, + me and around 1/2 tank of fuel. Those #'s are from a dyno jet 248c, and corrected. I would guess my race weight around 3600 lbs back then.

 

I have to agree, until you run the car in real world condtions at the track than everything else is sort of calculated. A dyno is nothing more than another tool at a shop used to measure something. People often get caught up in the number they produce on the dyno, its really about accurately measuring and making the most gains. A dyno is a very handy tool for gaining HP and also tuning for optimum results. I have yet to see anything really fast on the dyno for 1/4 simulation, but have seen a bunch of 11's to 15's cars be almost right on with time slips!

 

So, all these guesses and you still havent told us what the simulator said? I'll stick to my guess of high 12's... I'm interested in knowing how good my mental dyno is

 

The dyno said 12.33 111 mph. I would say with slicks and everyhthing going right I think more like mid to high 12's also. I made about 5 runs all within a couple of tenths. Mph is pretty decent, usally the most accurate for comparing with time slips !
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Hay 88 iroc who does your engine work, machine work ? In jersey