Norris design dyno'd their engine on an engine dyno and in the car!

they recorded a 24% dereace from crank to wheel!

not sure what dyno used. try looking on htier site.

thanks Chris.

 

I'm saying that the percentage of drivetrain loss is inconsistent between two engines of very different power levels in the same car.

Let's say that we put an EVO on virtually weightless dyno rollers with no loading, and so we isolate the drivetrain itself as the only load. Let's say that we determine how much bhp it takes to accelerate the wheels at the same rate a 600bhp EVO accelerates on the street. A figure of 25% tells us that it requires 150bhp to accelerate the wheels with no loading, which means that a 600bhp EVO only puts 450whp to the ground.

If this seems like an unrealistic power loss to you, it should, because it is.

We know what power levels turbos can realistically achieve because we have compressor maps that tell us where the turbo reaches choke flow (the ultimate limit). We also know real-world average whp from 1/4 mi traps. In the most extreme examples, with setups that appear to be wringing every last bit from a given turbo, the difference between the advertised choke limit and the estimated average whp isn't anywhere near 25%. In fact, for an EVO that gives 400whp on a Dynojet, I'd put the figure for actual drivetrain losses closer to half that figure. For an EVO making less than that, I'd estimate the drivetrain losses at a maybe a few percent more, for an EVO making 600bhp, a few percent less.

 

I did, and I didn't find anything like that.

What I did do however is compare engine and chassis dyno numbers from tone of heir own cars, and 1/4 ET and trap speed as well. I found nowhere near 24%, and I don't believe that number for a minute (neither should they).

Norris Phase 2 Evo 7
Engine Dyno - 730bhp
1/4 mi trap - 141.6mph
Weight 3168 lbs with driver

Estimated avg whp from trap speed calculation and weight = 702whp (4% loss).



Norris EVO 7 RS
Engine Dyno - 684bhp & 578 ft/lbs (2.1 bar)
Interpro Chassis Dyno - no bhp reading & 608 ft/lbs
G-Force - 715whp & 602 ft/lbs

Wow, the chassis dyno and G-Force recorded a higher number than the engine dyno. No 24% loss there.


In short, I feel it safe to assume at this point that the 24% number allegedly quoted isn't exactly reliable to say the least.

Just my two cents worth.

 

I give my modest contribution to this thread, as i think it's very interesting. Here in Italy i have a 4x4 dyno, braked type ( not inertial, i don't know the exact terminology in english, i'm sorry, i hope you can understand the same....), and going on it with a totally original evo i usually have between 205 and 210 wheel hp, with a transmission loss about 26%, and the crank result gives about 282/283 hp.
Well, when rolling my TME, with stroker, GT35R, all stuffs, at 2.4 bar (35 psi, i think) with 100 oct Ron Shell Vpower, i reach about 510/515 whp, with 29% of transmission loss, with a crank result of 720/725 hp, and i don't see particular differences from us dyno results, only in rare cases i see great results, of over 350 whp with a standard turbo, and i have some difficulties to believe to those results, i think sometimes there's a little of confusion between whp and crank hp, 350 whp shoul refer to almost 450 crank hp, not so easy, for my modest opinion....
My dyno is brand new, it's a Dim Sport with Rotronics software, and testing various cars results are in line with manufacturers hp, only a few hp less then declared from them.....
Excuse me again for bad english, i'm doing my best.....

 

The dyno you are speaking about is an 'eddy current' dyno (e.g. Mustang, Dyno Dynamics). These dynos are very good for creating real loading conditions, but they give low whp numbers.

Factory claim for an EVO 8 is 271bhp.

A Dynojet shows 235 whp = 13.3% loss

A Dyno Dynamics shows 210 whp = 22.5% loss

This is why your 26% number is unreliable and almost certainly erroneous.

 

I knew that, concerning european evos, power declaration is 276 bhp ( british horse power ) that equate to 280 din hp, and, looking at circulation document, they talk about 206 kw, that divided for 0.736, give 280 hp, perhaps part of the difference is in this particular, and maybe our dyno bench gives a little low numbers......
Btw, many rolling results, from various dyno benches, of different brands, Vamag, Maha, Bosch, and Dim Sport, gave similar results, with variations between 1 and 2%, i've tested this because i did with the same car, an original Evo VII, tests on each of them, for evaluating which one was the best to purchase..

 

My car was built and dyno`d by GT ART in UK!
They said 561whp and 718,2 hp at the flywheel..
That is about 25% loss.

 

Do you have both engine dyno and chassis dyno data that shows those results or is someone guessing? If the latter is your source, they may as well have said it made 1000hp at the flywheel, but that doesn't make it correct either. Even if you did have data from both dynos, if the chassis dyno reads low (as several do), then you obviously cannot assume those numbers to be absolute, in which case your 25% figure doesn't work.

 

I guess I will jump with my .02

It doesnt matter simply put. If you want to know your true TQ to the ground you need to multiply it through the transmission and driveline... you make much more TQ to the ground than you do at the motor (Aside from the overdrive gear).

So put that in your pipe and smoke it

All these stupid dyno numbers and questions make me sick. Do people honestly think they mean anything what so ever? Ive beaten 600HP+ Vettes from a roll. No matter how you look at it, he should have easily beat my car (Less weight at the time, less air resistance, less drivetrain loss, etc...). Somehow I beat the guy. I dont believe for a second my car makes 600+ horses... not at that time at least.

Dynos are good to find improvements on a vehicle. Same vehicle, same dyno, same settings. Do a few pulls changing things like timing, AFR or even parts. If the number goes up it is good. If it goes down its bad. Trying to compare dyno numbers to other cars is pretty much worthless IMO. I mean its bad enough that people strut thier stuff with dyno numbers but now it has gotten to the point where people claim different numbers then they actually hit (Like someone on Buschurs dyno will make say 400 but they claim it is a 450 horse car.... figure that one out).

 

the problem is chassis dynos and engine dynos all come in many varieties and proprietary designs.

the entire subject is subjective. if you compare a dynojet number to one brand of engine dyno you come up with one percentage. if you compare mustang to that same one you get another percentage and if you take into consideration the underrating that goes on in many manufacturer's marketing... where are you left?

i agree with ted b's analysis. the drivetrain losses like many other things in life are described by a logrithmic curve.

classic case of people using the tools correctly. i agree.

 

damn those british horse power numbers

 

British horses are stronger then American ones or what? lol

 

Stating that "in general AWD cars lose xx%" is just plain silly since every AWD car is built different and it is these differences which either increase or decrease the working friction throughout the driveline, causing losses. Not to mention losses through gearing.

Ted is on the best track here to find the closest % of driveline losses. As Ted describes above, you can simply take the rated hp numbers from Mitsu (~271 or 273 if you will) and then find the average for ppl dyno'ing stock cars. As he shows, this is in the 210-235whp range. Giving ~13-22% loss. Of course now ppl are going to say "well 13-22% isn't very accurate" and for the most part they are correct. but, since no 2 cars are alike coming off the assembly line and dynos aren't known to be very reliable, then this would give the best idea as to your actual drivetrain losses for your series of car; ie. evo. If you have a dyno sheet quoting your AWHP and you want to look tough with a high BHP, then go with the higher 22% loss and presto you have more BHP! But does it really matter what BHP you have anyway?

my $0.02

 

Thank you all for you answers. Well, It is nice to know that my car could output that much. The guys at the dyno shop told me but I found it hard to belive. Thank you all for your kind reply

 

Norris Designs uses a Dyno Dynamics which is real close in accuracy to the 2000HP AWD Mustang Dyno...