Blackroc86

I was comaparing some of my gtech comp pro runs and one of them with a 100 shot had a very high mph. I wanted to know if others see a mph jump like this with nitrous?

JERRYWHO

My car at the strip runs 99 mph and with nitrous it runs 115 mph

Jerry

ede

i always equated MPH to HP, more of one equalls more of the other. lot of things can effect ETs but the MPH doesn't change, or change very much

Blackroc86

Here are a couple of the gtech runs. One on the motor and one with a 100 shot. I see Jerry's cars mph jumps a fair bit with the nitrous so maybe it is somewhat close. I know the gtech's mph is usually 3-4 mph higher than the track.

On Motor With 100 shot

60ft 1.972 1.962
330ft 5.171 4.992
1/8 7.81 @ 95.04 7.438 @ 103.59
1/4 11.995 @ 118.46 11.211@ 133.38
0-60mph 4.183 3.716

AlkyIROC

My truck usually runs around 87 mph in the 1/4 (very low 15's). With NOS it's run 101 mph (low to mid 13's). Not too bad for a 4600 pound daily driver.

Trevor86TA

Jerry picked up 16 mph on a 210 shot.
You picked up 15 mph on a 100 shot.

I know that different kits are rated differently, but on cars that are relatively similar in weight, one shouldn't need twice as big of a hit to have similar gains.

Calculating horsepower derived from MPH and weight.

3600 lbs + 133 mph = 661 rwhp
3600 lbs + 118 mph = 462 rwhp
http://www.midweststreetmachine.com/etcalc.htm

Is this 133 run the norm or the exception? I think that Jeremy (95redz) picks up 10mph or so on a 100 shot (NX kit) in a car that likely weighs about 3600 with driver.

JERRYWHO

I pick up 2.14 seconds
He picks up .78 seconds

My car is geared to low for good mph it has stock heads and cam and its all done at the 1000 ft mark and in the lights it turning 5800 way over peak hp but the car is set up for a motor that spins 6800 in the lights.

He must have gear to spare and thats the reason for the good mph gain

Jerry

Blackroc86

This is making more sense now. I have a 3.73 gear and I am running a 28" tall tire. So I have more upside with the mph I guess.

Trevor. I have had a low et or 11.02 with a 100 shot and the mph was similar.

unknown_host

iTrader: (1)

Horsepower ratings with nitrous mean nothing. A plate setup jetted for 100 horsepower (NOS jetting, not sure of others) can make upwards of 190 additional horsepower with the proper engine setup.

Blackroc86

I checked out the mph and weight to hp calculator at prestage.com

My car is more like 3300 lbs as it is stripped with lightweight Weld wheels. If you deduct 4 mph that the gtechs are noted for you have 129mph left.

Their calculator says to trap 129mph with a 3300lb car it would take 553hp. So that makes sense with the 100 shot.

ontogenesis

You also have to keep in mind that not all nitrous companies measure hp gains the same, I know the NX's ratings are supposed to be from the rear wheels, where as alot (most?) other companies get their ratings from the flywheel.

onyx: how stripped is your car to get that weight and how accurate is the scale? the local Cat scale says my car is a full 220lbs less than that and I've got a full interior, barely any weight mods.

Blackroc86

I just took a rough guess at the weight. I have aluminum heads, mostly bare under the hood, fiberglass hood, no interior or carpeting, 6 pt bar, SFC's. I really need to get it on a scale and see what it weighs.

Trevor86TA

Wow. Your car weighs 3080 w/ driver and barely any weight mods? My TA is a pig at 3560 W/O driver.

AlkyIROC

The nitrous HP ratings are also calculated at 1200 psi bottle pressure. It only takes one pass to get that bottle cold and the pressure will drop.

The setup on my truck is set for 150hp. Usually when the bottle is cold I only see an improvement equivalent to 100-110 hp. The one day I got my best run the bottle was hot and was almost at 1200 psi. Track conditions were perfect and I saw a 165 hp increase on that run. The truck engine only puts out around 260 hp but also puts out close to 400 lb ft or torque.