Dyno results... I'm missing some HP.

[Moses]

pwd72 had the best guess. My peak was 230.8 HP and 238.8 torque.

I changed out my exhaust for a "cat only" arrangement like JonT, but found only marginal changes.

Preliminarily, it looks as if the computer may not be switching to "open circuit" on full throttle because the fuel/air ratio is steady like a rock above 2,500 rpm (13-14).

As a note- I have adjusted the throttle cable and I am getting WOT.

The motor runs and idles well without smoke.

Any ideas where to begin the search for the elusive 25 HP? With my current setup, I should have 250-260 RWHP. As a start, I will have the engine evaluated on the computer. Any ideas?

As an aside, Ray at the new Dyno lab in San Ramon is a great guy. (Even though my name isn't Mike )

The great upside is the insane torque curve! Yikes!!!

[Moses]

Easier to read.

[jtkkz]

Correction: His name is Ray

I was there last night getting my car dynoed as well.

[beepbeep]

If it's a rolling road they can usually measure driveline losses by measurin time it takes for rollers to coast to stop. That way, you can have exact numbers at the engine.

[Moses]

Originally posted by jtkkz
Correction: His name is Ray

I was there last night getting my car dynoed as well.

Sometimes I am Gods own idiot.

[IMONBOOST]

With the weird torque curve figures and lack of HP my guess is your varioram is not working,

[dd74]

Can it be the chip?

I don't know: all that newfangled electronics scares my simple mind.

I'm just a CIS man.

[beepbeep]

And yeah, the fact that power peaks around 5700 RPM makes me think that your Varioram gadget isn't opening correctly...

[dd74]

I wondered that, too. Plus "two bumps" in the torque area? Isn't that supposed to be rather linear, i.e. goes up, levels a bit, then drops down?

[Bill Verburg]

Most vrams that I have seen are right around 240hp/220ft-lbs &#177. The thing I notice is that the torque peak is ~1000rpm lower than usual, it does seem to have the correct shape and width. I suspect that the poor Ca. gas. is at least partly to blame. All the cars I have seen done had at least 94 octane. With the mild cams used on modern stock smog motors they are relatively immune to exhaust mods, as long as there is sufficient flow capacity.

[scca_ita]

I thought the second stage was to open around 4300 - 4500 rpms. I would make sure you have a good vacuum canister. Yours appear to have something happening around 5K rpms. Maybe this is due to lack of vacuum, causing late and incomplete opening of the secondaries. I thought I read somewhere that Steve Timmins had to use two vacuum canisters but I may be mistaken.

Also verify the dme numbers too.

[Moses]

In fact my "mechanic" told me that the Varioram was not hooked up. Silly me. I bought a Varioram thinking it would have, well... Varioram.

He says the HP gains with Varioram are insignificant.

How difficult is it to make the Varioram functional. Will it make a big difference?

Thanks.

[rfng]

Originally posted by Moses
In fact my "mechanic" told me that the Varioram was not hooked up. Silly me. I bought a Varioram thinking it would have, well... Varioram.

He says the HP gains with Varioram are insignificant.

How difficult is it to make the Varioram functional. Will it make a big difference?

Thanks.

I don't know why your disappointed? Dynos vary significantly. I remember you saying how fast it was? Why would a dyno number even matter, its how the car performs and whether you are happy with it.

When I dynoed my SC with the first turbocharger running 3 psi, it recorded 229 hp 256 in torque at 4100 and held to redline, which I didn't believe that 3 psi would jump the hp by 57 hp and 70-80 ft lbs of torque. It depends on the dyno. I've seen the same race car placed on a chasis dyno and put out 200 horsepower less than on a engine dyno.

As for your number its in the ball park. Average of the two runs 227 at the wheels. 15% loss-269 20% loss-281, I think your within the acceptable level for that engine. Even if it not, what are you losing maybe 10-15, not a big deal. I'm not sure what exchanger you are using but if your using a backdate exhaust, that could account for the 10-15 horsepower your missing, depending on what you use for the drive train loss of 15-20 percent.

I would bet that your 227 horsepower will blow away alot of guys who claim 270 plus on a smaller motor. Just something to think about.

[beepbeep]

Moses:

Your mechanic doesn't know what he is talking about. Varioram does help! Whole engine equipped with Varioram is tuned for torque, untill you hit 5800 RPM's when it shortens the intake stacks. Do you really believe Porsche would put it there if it was "insignificant"? Actually, Varioram doesn't open at all until 5000 RPM and goes trough three stages between 5000 RPM and 5800RPM:

Below 5,000 rpm (left A and top right) : long pipes; resonance intake disabled.
5,000-5,800 rpm (left B and middle right) : long pipes plus short-pipe resonance intake, with one of the interconnected pipes of the resonance intake closed.

Above 5,800 rpm (left C and bottom right): long pipes plus short-pipe resonance intake, with both interconnected pipes of the resonance intake opened.





Whatever SC people say, 230HP sucks bigtime... especially thinking about all the fuss you went trough to install this engine.

Transmission losses are almost never as high as 15% but are something arounf 9%...so your engine makes 252hp right now...that sucks and you shouldn't be satisfied with that, 252 is 20hp extra than euro Carrera, with 0.4L bigger engine, better heads, better cams and dual plugs?! On the top of it, it's euro 993 Varioram mill and it should absolutely scream. My guesstimate is that you are down 28 to 30 hp beacuse of your mechanics lazyness.

No go and hook up that thing up or change your plenum to something else...or you will be driving around in car tuned for shopping! When you are done with that and everything works fine, go and get the chip! That thing should dyno close to 300hp with chip and working gadgets.

And yeah, get rid of your "mechanic" ...

[IMONBOOST]

I am sure the varioram will make a big difference when hooked up, specially when it is currentlly fixed for the low end. You will never get the high HP until you activate the varioram or change intake like beepbeep said.

[IMONBOOST]

Why don't you force the butterflies open and see if your buttmeter detects some improvement above 4,000 rpm. You will probably see dome decrease below 4,000 rpm but I would doubt it would be as significant as the improvement above 4000 rpm.

[Wil Ferch]

Hold Everything ! ....

I think we're missing a potentially crucial point, and one I have mentioned before in dyno posts...

What is "Standard HP" on the graph? I suspect that is the hp extracted by mathematical formula from real-time-torque measurement ( same as all other inertial dynos)...BUT...that it may not atmospherically compensate to some standard, reference conditions that can be used for valid comparisons to dyno runs done elsewhere.

Here's my point....
If the graph was instead calibrated to "SAE Standard" hp conditions, the actual dyno run would take *that day's* air temperature, humidity, and barometric pressure ( elevation effect)...and compare it to SAE's standard set of 14.7 psia ( sea level elevation), 50% relative humidity and reference temp , which I believe to be either 70 degF or the nearly identical 20 degC.

Done this way, the printout would also include a term called "CF" ..or correction factor...on the lower portion of the printout. As an example of how this might work..I compared two dyno runs ...each on stock 3.2's . One car was at a Denver type of elevation, etc, and the other car was done at a coastal city. It was amazing how similar the two graphs were since both were done to SAE standard conditions...however both had wildly different CF's that made this comparison possible. The Denver car was "actually" making less hp at that location, but once corrected to sea-level conditions it showed remarkable consistency to the other car's curves....

---Wil Ferch

[IMONBOOST]

I think most of us are going with the HP Flat spot above 5,000 rather than the actual numbers.

[juanbenae]

moses, where in san ramon is this dyno place? i would like to check it out when im in town next.

thanx

[Moses]

Originally posted by k911sc
moses, where in san ramon is this dyno place? i would like to check it out when im in town next.

thanx

25 Beta Court

(behind Morgan's supply)