Is my 328i still making good HP???

SinCity328 · #1 (**permalink**) 10-06-2003, 04:53 PM

I was wondering if anyone could tell if my 328I is producing good HP at the wheels?

I just G-Teched it and got 160HP to the wheels.

The engine has about 90,000 miles on it,and i recently changed the plugs, is 160 good or bad???

1997 328i w/Dinan intake

Recent compression test

5- cylinders 194psi
1- cylinder 186 psi

Thanks,
Maurice

tdc · #2 (**permalink**) 10-06-2003, 05:12 PM

188 HP if you have a manual (using 15% drivetrain loss)

200 HP if you have an automatic (using 20% drivetrain loss)

ryan8624 · #3 (**permalink**) 10-06-2003, 05:28 PM

Quote:

Originally posted by tdc
188 HP if you have a manual (using 15% drivetrain loss)

200 HP if you have an automatic (using 20% drivetrain loss)

uhh...

those numbers dont make and sence, try again.

tdc · #4 (**permalink**) 10-06-2003, 05:36 PM

How do you figure? Simple math, my friend.

160 WHP + Drivetrain loss HP = Crank HP

Drivetrain loss is calculated simply by taking the percentage of the Crank HP. So, it's a simple algebraic equation.

x - .15x = 160HP

1x - .15x = 160

.85x = 160

x = 160/.85 = 188.2

So what doesn't make sense? And please learn how to type and spell.

SinCity328 · #5 (**permalink**) 10-06-2003, 05:42 PM

So my car stock is rated at 193hp; 200hp with an intake (AUTO) and 90k sounds good to me.

Thanks for the help,
Maurice

BeArs · #6 (**permalink**) 10-06-2003, 06:19 PM

I think I'm stupid or something but he has more HP with an automatic ;o ? correct me if I'm wrong please

][-][aste · #7 (**permalink**) 10-06-2003, 06:48 PM

he is saying that 160 is the RWHP, this # is a constant

by using that # (160) you can findout what your Crank HP is... therefor since Auto is 20% loss and Manual is 15% use a constant Crank HP and u'll see that an auto will have less RWHP.

Simple Math.

tdc · #8 (**permalink**) 10-06-2003, 07:05 PM

Quote:

Originally posted by ][-][aste
he is saying that 160 is the RWHP, this # is a constant

by using that # (160) you can findout what your Crank HP is... therefor since Auto is 20% loss and Manual is 15% use a constant Crank HP and u'll see that an auto will have less RWHP.

Simple Math.

Exactly.

200 HP is his Crank HP (which is the constant). If he had a manual transmission, his WHP would have been 170HP.

kiley_sean · #9 (**permalink**) 10-06-2003, 08:35 PM

Quote:

Originally posted by BeArs
I think I'm stupid or something but he has more HP with an automatic ;o ? correct me if I'm wrong please

The torque converter in the auto. trannys really rob alot of torque and that is why the loss is higher. If you have two identical cars, with one being auto. and one being manual, and they both put down 200 whp, the auto. has the stronger engine.

Just like FWD cars have an even less transfer loss. They don't have to send their power down a driveshaft and have it turn 90 dgrees at the differential, because the engine is transversed up front, and there is no need to convert the direction of the power.

Bottomline, crank HP means shit. It's what hits the ground that matters. The transfer loss can come down to having bigger 18" wheels, shitty driveline, etc. JMO.