RAMPANT

iTrader: (17)

I figure that the hardcore racers will be the mostly likely place to get a straight answer.

I have a buddy who has a fast newer Charger. It has a 423ci Hemi (they all call them 426s? WTF), with a 1.9L blower. It has made 605rwhp with a near flat torque curve over 600ft.tq from 3000rpm on up one dynojet. He added meth and it made torque even lower and went up to 620rwhp on another dynojet. The car has gone 10.5@134.5 with a rough race weight of 4400-4500lbs. He is now trying to say because an online calculator shows 770rwhp for that mph, that this is what it is making. I know both of the dynos, and while they are not happy, they are not off by 150 rwhp.

As I see it, these calculators must be more oriented towards NA power which have a lot less power under the curve. Or are they just full of crap, period.

The calculator he is using showed my old 412 making 585rwhp when it never dyno'd better than 512 as it was set up when it ran 129mph.

He has had several 131-133 passes, this was the first 134.

I have looked for FI calculators, but there has to be a difference.

Thoughts?

BAKED

iTrader: (14)

Those calculators are for hp at the flywheel. Not at the rear wheels.

RAMPANT

iTrader: (17)

There are several that show both, but this is the one we were discussing.

http://vexer.com/automotive-tools/1-...MPH-calculator

c0ncEpT

iTrader: (4)

So you already know what its making at the wheels via dyno and what it runs at the track. Why are you even talking about some bullshit calculator? Don't you already have all the information you need?

Unless hes just trying to boost his ego that conversation is totally worthless.

joelster

It sounds like that is what the Challenger owner is trying to do. I see the point the op is making though. The 2 dyno numbers are there plain as day, and so is the ET slip. The only 2 variables that I can think of is MAYBE he dynoed it in the summer when it was 85 degrees out, and then raced it in the fall with some great air, or he is lying about his weight.

Just out of curiosity what wheels does he run on the track passes?

RAMPANT

iTrader: (17)

Mmmm, yes, we agree. I am trying to be nice, but also I would think a FI 620rwhp set up would easily out perform a 620 rwhp NA set up in the same car. Just due to the sheer under the curve power. If he uses the ET version it gets closer, but still I would guess inflated by 80rwhp.

I was just curious if anyone has seen a calculator specifically for forced induction drivetrains, and see if I could bring a little common sense to the discussion.

As mentioned the same calculator inflated my numbers by 75rwhp vs reality of what it dyno'd.

RAMPANT

iTrader: (17)

Pretty sure the weight can not be too far off. My DD is and SRT8 Magnum and it does weigh in over 4200lbs, and he is a big guy.

Rims I am not 100% on. I know he has some light Forgestars, but I think they are his street set up. Pretty sure on the strip he is using Hoosier DRs.

We have just been debating and thought I would check in with the hardcore guys.

He has owned and driven a 7sec Firebird that trapped over 190mph, so it does seem funny he is trying to inflate the numbers, but he is. Either way it is a really fast 4 door street car.

joelster

The calculators are generous in the % slip of the torque converter. They usually use 10%. Some cars can slip 15-20%. That's why their rwhp is inflated when you plug in your timeslip and have a valid dyno reading.

black00ssFL

iTrader: (24)

Let him claim 770whp, and then look like an idiot when he loses to guys with 550whp.