horsepower

[wrxallwheel]

Dodge claims 215 horse from the 2.4 liter but dyno 223 to the wheels.So what I'am trying to say a front Wheel drive car loses about 25 to 30 percent to the wheel therefore at the crank it should be a little over 250hp.

[boosted 4]

Originally posted by wrxallwheel
Dodge claims 215 horse from the 2.4 liter but dyno 223 to the wheels.So what I'am trying to say a front Wheel drive car loses about 25 to 30 percent to the wheel therefore at the crank it should be a little over 250hp.

Do you mean FWD (front wheel drive) or AWD (all wheel drive)? I think the WRX looses between 23- 26% at the wheels, where as the FWD vehicle might loose 12- 15%.

As far as the SRT4 goes, keep in mind that Dodge wasn't using Dynojets to come up with those HP ratings. The Dyno jet dynos are notorious for reading high... I think Vishnu Performance (aka Shiv) has some more acurate data if I'm not mistaken.

[RSXSucks]

Originally posted by boosted 4
As far as the SRT4 goes, keep in mind that Dodge wasn't using Dynojets to come up with those HP ratings. The Dyno jet dynos are notorious for reading high... I think Vishnu Performance (aka Shiv) has some more acurate data if I'm not mistaken.

I think the stock track times for the SRT-4 confirm the fact that they are vastly underrated from the factory. How else could a FWD 215HP car consistently beat an AWD 227HP car to the end of the 1/4? The weight difference isn't that big.

[capt'n'caveman]

i think is the one time where a car manfacturer rated the hp at the wheel instead of at the crank

[wrxallwheel]

well a stock wrx well dyno 170hp to all the wheel so it lost about 49hp that about 30 to 35 percent a front wheel drive car loses about 20 to 30 horse power to the wheel.But the good thing a awd car has outstading traction so that make up for the horse power lost.

[boosted 4]

Originally posted by RSXSucks
I think the stock track times for the SRT-4 confirm the fact that they are vastly underrated from the factory. How else could a FWD 215HP car consistently beat an AWD 227HP car to the end of the 1/4? The weight difference isn't that big.

Okay, perhaps the SRT4's crank HP is under rated. So let's say in stock form it's putting down 205whp and the WRX is putting down 170whp. With the extra weight of the WRX and the SRT4 putting down more power to the ground I think it makes perfect since.

They're both low 14 car's (driver dependent of course), the WRX get's the launch giving it the head start and the higher whp and lighter SRT4 plays catch up and barely bests it at the end.

Pretty simple, really.

[randy98mtu]

FWD with a manual doesn't lose that much. My previous car (94 Taurus SHO) lost about 17% while the auto version lost 22-25, IIRC. The worst FWD was the Chyrsler M that had the engine mounted longitudinal (sp) instead of horizontal (I think I phrased that right. The engine was front back instead of side side) Turning the power 90 deg wasted their 30 hp advantage to the SHO so they were about equal to the ground, auto trans vs auto trans.

[Roadrunr]

Originally posted by wrxallwheel
well a stock wrx well dyno 170hp to all the wheel so it lost about 49hp that about 30 to 35 percent a front wheel drive car loses about 20 to 30 horse power to the wheel.But the good thing a awd car has outstading traction so that make up for the horse power lost.

Actually, it's 25.1%, not 30-35% and it's rated 227 crank, 227-170 is 57, not 49. Boosted 4 was right on the money based on those numbers.

[Wannabe]

Just a little reminder for a side note. Peak horsepower has little to do with 1/4 mile times. Torque multiplication in regards to transmission ratios, gear ratios, sweepable horsepower, torque, cubic inches, power band, and gearing in relation to the power band are about the most important. (Unless the car is an auto- then the converter is more important than they all!)
I know that we all know this, but sometimes it gets lost in peak HP numbers.

[RSXSucks]

Originally posted by Wannabe
Just a little reminder for a side note. Peak horsepower has little to do with 1/4 mile times. Torque multiplication in regards to transmission ratios, gear ratios, sweepable horsepower, torque, cubic inches, power band, and gearing in relation to the power band are about the most important. (Unless the car is an auto- then the converter is more important than they all!)
I know that we all know this, but sometimes it gets lost in peak HP numbers.

Absolutely, one cannot solely look at peak HP. Out of everything you listed though, you missed what I believe are the other 2 most important factors though: drivetrain layout and weight. Given HP, weight, and drivetrain layout (and nothing more) for any 2 cars and with pretty good certainty (no, obviously not 100%), you could determine which should win the 1/4.

I think most people look at the things that can easily be used to categorize cars into segments to guess at what their 1/4 times are going to be and there is nothing wrong with that. Peak HP is an easy number to quantify, torque curves and gear ratios are not. I once saw an extremely good graph of hp/weight vs 1/4 track times for RWD cars and as much as the other factors can act as a tie breaker, the data showed that hp/weight was an extremely good indication of how a car would perform in the 1/4. So although something like gear ratios do affect 1/4, most car manufacturers put in moderately good gear ratios so that empirically, it usually ends up being a pretty minor component of 1/4 times. I suppose a car company could put really really bad ratios in a car that would hurt the times, but so far, most don't.

[boosted 4]

I didn't mention gearing, final drives, or even how many gears each has on my above post. I guess I was just taking that for granted since I was already kind of familiar with the gearing in both cars. I think this one had been discussed here before on the gearing of the SRT4 vs WRX and the final drives and gear ratios were close.

I think the biggest factor between the two, stock for stock, is the weight diff and power to the ground which allows the SRT4 (once it's going) to catch the WRX at the end. Of course this one has been told a thousand times

[Wannabe]

Yes! Dead on! Weight is a huge factor. They stated that the two cars in questions were at about the same weight, so I carelessly overlooked that.
And the other factor that is often overlooked, is a large one on this board, and that is traction. My car will easily double it's time in the 1/4 without traction. That is where all wheel drive comes into play.
Now, the gears is an interesting one. With the dragsters and doorcars of the NHRA in Super Eliminator, Super Comp and Super Gas, the 7.90, 8.90 and 9.90 classes, the cars almost always go quicker by 2 tenths with a 2 speed than a three speed. Same weight, etc. (Just an interesting tidbit of information.)

[brembo]

Road and Track put one on the dyno. Said it was puttin down 222 hp TO THE WHEELS. Coast-down test showed a 16 hp driveline loss, so the final tally is 238 crank hp. 246 ft/lbs to the wheel, if yer curious, states this was a Dynojet.

*edit*

This is the June 2003 issue, the one with the Saleen S7 on the front, and a STi/Lancer comparo...guess why I bought this issue? The Lancer won due to better pricing