Just wondering about this. I've read from a bunch of places that the stock RA dynos at about 155-157hp at the wheels. That's only 3-4% loss from the drive train. I know the % thing is inaccurate, but the lower bound for a fairly efficient FWD manual is 12%. Using the lower bound, assuming our transmission isn't somehow special, the engine should be making 175hp at least. Is this just out of left field or does it make any sense? 3-4% loss doesn't make sense to me, our transmission is just your average 5 speed.
Also, why would Mitsu under-rate the engine, assuming that's what's going on here?

 

There's a lot of variables. The Ralliart dynos anywhere from 125 (mustang)-155 (dynojet) at the wheels, depending on the dyno. Secondly, no two engines are identical. Some engines from the same assembly line will perform better than others, as something might be 1/1000th of an inch different. Nobody has dyno'd their engine, to my knowledge, but I imagine that it'd dyno from 162-168 bhp.

From a manufacturer's standpoint, it's better to underrate the engine. Mazda is the perfect example of why. When the RX-8 came out, it was overrated and customers threw a fit.

 

Gotcha. What's the difference between a mustang dyno and a dynojet? I thought they were the same thing. I guess the numbers I've seen were from a dynojet. Something odd is this site,
http://www.sportcompactcarweb.com/ro...rs_comparison/

They have the specs down near the bottom. I don't trust that they actually tested the hp, but odd that the Sentra's numbers are less than the RA's. Not saying it's proof of anything, but odd. We could assume they used the same type of dyno, unless they just grabbed those numbers off the net, the RA being from a dynojet and the Sentra being from a mustang dyno.

 

Different brands of dynos. Each brand of dyno measures a bit differently. That's why it's so important to always measure your car on the same dyno. It's also why companies such as RRM don't like posting dyno numbers. If they did all their tuning on a Mustang dyno, which typically reads lower than all other dyno brands, people would assume their products aren't making as much power as their competitor, which might be using a dynojet that typically measures higher than other dynos.

I'm sure SCC dyno'd the cars, however, the RA they had was probably making more than the advertised 162, but no way to tell for sure without pulling the engine.

 

that thing about mustang dynos gives less WHP its crap, a mustang dyno can give you less WHP or way more WHP than a dynojet , why!?

Cause on a mustang dyno you can set the dyno how ever you want, like the weight of the car, and things like that, so thats why people get, less or more WHP on a mustang dyno

on a DynoJET you cant change any settings of the dyno, so its very presice (<is that a real word? hehe),

and I dont think a RA stock will put 155 on the wheels, like the guy said a car usually have a 12- 15% loss because of the drive train

also if a RA stock put 155 to the wheels, why are we buying headers and intakes that suppose to take our cars to 155-160 WHP?????

just my 2 cents

 

Dyno sheets have been posted with ranges from 130-157 whp stock.

 

stock hp is like what 162ish so your saying im doing 150whp ish stock hmm 10hp lose not that bad

 

That's assuming Mitsu's published rating is accurate. I believe there's quite a few Ralliarts there putting out a bit more than 162 bhp.

 

Every dyno is different. Every day is different when you test. Every car is different.

At this rate dyno numbers should be taken with a grain of salt. Besides we are not some 600+ whp Supras that go to the track and run 14's. If you really want to know how fast you are then you need to go to drag strip. A mph will show the cars capabilities. The time will show the drivers capabilities. Only if the driver really really sucks then would it affect the mph.

 

more than 162 bhp is that possible maybe mine has more than becuase i took down a 2006 civic si with no competion those are like 197hp hmm thats for you

 

More likely had a ****ty driver.

 

Crappy driver plus the Civic doesn't have torque to match that HP, but that's a discussion for the Vs. thread.

 

Only thing I can add to the variances between dyno runs is: It also depends on how your car is strapped down ON the rollers. You can get several different (but close) #'s on the same exact dyno with the only change being where on the rollers your tires are and how much pressure is holding your tires onto the rollers. Doesn't sound like much but it can affect things to some degree. It's all relative anyways.... 100whp was based off of a KZ1000 iirc but I could be wrong about the specific motorcycle, it's been a few years since I read the article.

 

touchy subject eh? I should run on my friend's dyno to see what comes up.. i'm not stock though... but it'd be interesting.

 

I pulled 171 with Injen CAI, RRm Downpipe and EvoJoe's Pulley. Stock Exhaust piping> i was throwing low 15's all day. I added 2.25 exhaust and piggyback(untuned) and ran a 15.10 @ 91 in a very zhitty pass