So according to your logic if I sell and exhaust and claim 30 hp, you will subtract 6 hp for hype, then 15% for driveline loss and then believe the rest of the gain without any proof?

I have built an exhaust that produces 25 hp and costs $2,500. Not too had of a $ to HP ratio. PM me and I will tell you where to send the checks.

 

just wear a facemask, a surgical one is cool. and that last comment about the exhaust, the only problem with that is that no v6 na exhaust dyno plot has ever shown a whp gain anywhere near that whereas i could post a thousand dyno's of v6 or even an i4 that show ten hp gains at the wheels with a chip...that's the difference...but i too am a fan of dyno's, don't talk about gains without one from no on, please...

 

Oh come on x'ed Toluene and Xylene are already in gasoline as well as Benzene and a few other hydrocarbons. Higher concentrations of these hydrocarbons = Higher octane, to a point. No more or less noxious fumes than the MMT that the refineries put in already. Now if you're thinking of the nitro methane family, that's a different story... That exhaust will burn your eyes and lungs...

 

Ahhhh... I love the smell of nitro in the morning!

 

i was just stating that as a general rule of thumb. this is a tuner of chips, not a custom maker of high end exhaust systems.

think of AEM intakes. claim 20, more of the reality is 10. i'm just giving my opinion for generally available mass produced items. it is a rule of thumb not an algorithm.

 

My point is simply that many people and companies make all sorts of claims. Lots of these claims have been proved to be BS by someone taking the time to verify them. I am just trying to figure out why some people are so willing to believe and recite manufacturers claims without any proof at all.

 

You guys are right... Marketing claims of HP increases are usually baseless or over-inflated. I was even shocked when I had my completely stock Crossfire dyno'd at the track in 2004.

Even the manufacturer inflates the HP. I have since found that the MB W112 engine rated at 215 HP was done with an engine removed from the vehicle and put onto a test machine. Not a single part of the car was attached, nor were any of the accessory pumps, alternator etc. It was literally an engine on a platform attached to a dyno with advanced timing and none of the restrictive exhaust components. And this was done with the original W112 engine for the SLK320 in 1999...

So, our baseline of 215 is useless.

I go with the "50%" of any claim for aftermarket performance HP...

 

So your saying that the engine has more then the 215 hp claimed by MB. I wonder what the HP was before they added all the other trash you spoke of... lol this engine must be kicking 260 hp before it is placed into the engine compartment and the AC belt is set in place. HOOAH

 

What part of my previous post led you to believe that the engine is delivering 260 hp ? The darn motor spec. HP was created on a test platform in 1999 with a W112 connected to a test machine without any peripheral accessories...

The actual HP at the wheel is substantially less than the 215... Never mind... just go back and re-read the post... Or take your car to a dyno and cry when it plots a HP curve barely making 200 at the wheel...

Then do the math... 203 hp / 3,100 lbs Gee Whiz... What a rocket ship we have !!! I think I'll buy a few more of them...

 

This is actually par for the course. Any HP number you see posted by a manufacturer will be power measured at the crankshaft and will usually be corrected for temperature, humidity, and altitude. In most cases, the power measured at the wheels will be 10 - 15 percent less due to driveline loss. The number you posted (203 HP) is in the 5 percent range, which is surprisingly efficient.

Case in point: My beloved Buell S1W "White Lightning" was marketed as having a 101 HP. My totally stock bike pulled 79 HP on the dyno. After installing an exhaust, intake, carb, and ignition module, the bike managed to crank out 92 HP. If I wanted to get a true 101 HP at the wheel then I would need to start doing internal work on the engine or add forced induction.

HDDP is correct in the fact that a good gauge of the "fun factor" of a vehicle is to look at the number pounds each HP has to push around. So using his numbers, the Crossfire comes in at 15.27 lbs/hp. The only way to increase the fun factor is to either gain HP or lose weight.

Let's look an another car that's in the ballpark with ours, the Nissan 350Z (with the track package). Here are the numbers from Sport Compact Car magazine:

Claimed HP: 287
Measured HP: 249
Curb weight: 3,197

That's a 14% loss of power and 12.8 lbs/hp

By comparison, the Dodge Viper has 6.8 lbs/hp and the Z06 Corvette has 6.3 lbs/hp, and my Buell has 4.6.

 

^^^ What he said. Is it possible that was the ft-lbs at the wheels? I'd expect ~185 whp/~200 wtq on a completely stock crossfire.

 

Hopefully HDDP can post the torque value as well. Speaking of torque, there's one other thing I wanted to mention. A lot of people bash the Crossfire for being down on HP but they forget to mention how that HP is delivered. If you'll look at my other post in a thread entitled Interesting things I found, you'll notice this:

90% of max torque is available from about 2,300-5,300 rpm, 98% of max torque is available from 3,000-4,500 rpm

HP is a measure of how much work an engine can do, but torque is a measure of how hard the engine can twist something. More torque equals perceived more oomph when you mash your right foot. In the case of the Crossfire all you have to do is keep the engine above 2,500 rpm to have a lot of fun.

Other cars may make more horsepower and torque but you have to keep the engine spinning at high rpms to find it. Take the 350Z example from my previous post: Peak HP hits at 6,200 rpm and peak torque hits at 4,800 rpm. The Crossfire does it at 5,700 rpm and 3,000 rpm respectively, which means that during everyday driving you will spend more time in the meaty part of the powerband. When you're in a "competitive" situation, it also means that you're less likely to have to downshift to achieve the desired results. This explains to me at least why Crossfire owners have reported beating other cars that make bigger HP/Torque numbers.

 

Bobs:
I'll have another dyno done on Feb. 4th at Buttonwillow Raceway and post the new #'s. I need it before I do the extrude hone process. I'll figure some way to post the print-out.

 

Well I took the plunge and had the Upsolute tuning done.
I had the "base map" (whatever that is) done. The guy that did it was great, quick turn around and very helpful.

I have no measurements, computer printouts, analysis, fancy charts, just the seat of my pants opinion.

IMHO the tuning is not worth it.

I installed the module and took the car out for a spin. I did notice a slight increase in acceleration but nothing that made me go holy crap. I did not get thrown back into my seat, burn the tires off the car, (first or second gear), it wasn't WOW... is the best way to describe the performance change. Again, my opinion, defiantly not worth the price.

 

I'll post my opinion in detail on this in the RACING forum tonight... I think I figured some more things out after this weekend at the track...

 

I just got my new left over 2005 crossfire and I love it. I live in Orlando Fl and would love to get a little more horsepower. I bought what I thought would help my car off ebay. The person sent me a resistor and said all I needed to do was push it in to the brown wires on my air sensor. From what everyone else is saying I am a little nervous doing this. Can anyone help me safely get more horsepower in Orlando.

Mick

 

Bet you five bucks that this won't provide a gain that you could prove. I will bet you five more that a reflashed ECU, courtesy of Upsolute, will. I would consider the upsolute reflash, and freeing up any restrictions in the exhaust system, if you are looking for a modest hp gain.

 

Get Upsolute plus a new grill from www.CTD-Germany.com! Contact guettler@CTD-Germany.com if you are interested!

 

Thanks for the info... Mick

 

Don't do it Mick! All these things do is make the PCM to read the air temperature to be colder than it really is which will cause it to richen-up the fuel mixture. You may get a bit more power but your mileage is going to go down the tubes and you will most likely fail any emissions testing your state may have.