piperporsche180944

Come on guys! Its not like he is making obscene power claims on a Honda forum without dyno charts (oh my honda b16 NA made 400whp and smoked a zr1). He has supplied us with dyno charts and the dyno shows that his 951 is not only beautiful, but a beast as well. Great numbers!

Also are those 18" wheels on your 944 in your avatar photo? Thanks.

asiancaucasian

Thanks!

Yep, those are 18" 997 replicas. They look great but I don't currently have them on my car as they're way too heavy for the track.

piperporsche180944

I'm looking at buying a set, how heavy are they compared to say...... D90s?

asiancaucasian

lol... I weighed them out. Fronts were 32lbs, rears were 38!

piperporsche180944

Holy jesus! I wonder if the genuine Porsche 997 wheels are lighter than the replicas.

95ONE

Why the hell do you start your runs so high up the revs? Do a 1/4mile run.. dont care about time.. just mph. 400whp at 3Klbs = 120mph trap.. on an average run.. an exceptionally poor run will net a few less mph. So.. weigh car.. tell us altitude/temp and then record it. that is truly all that is needed. Well, and some sticky tires if your running that kind of power.

TonyG

Not really... and the answer as to why is long and detailed... but the short version is that water and/or meth injection is a band-aid solution to the real problem... fuel quality.

And it's more than the R+M/2 octane rating that dictates how a particular engine will run on a given fuel...

Nothing like burning real race fuel.


TonyG

eclou

My entire car was held together with band-aids, which is why the LS1 goes in!

DanaT

I realize that dyno's, like any other instrument, can have errors. One of the biggest things, that i rarely see posted on dyno sheets is correction factors. Here in Denver that really matters as typical summer factors are 1.25 to 1.30. If that is applied applied to a turbo car it is somewhat misleading.

The NHRA applies half correction to turbo cars which is probably more realistic. However, when I get dyno sheets in Denver, I like to see uncorrected numbers.

If I take the car to a dragstrip, the ET/MPH gives me uncorrected time which should match with the dyno.

Case in point. The Dyno Dynamics vodoo machine "measured" 255rwhp uncorrected for my car. Using a 15% loss, that should be about 294crank hp in Denver. At the dragstip the car posted 103.89mph. On the dragstrip scale with all the crap in the car (fuel, me, spare tire, etc) the car weighed 3290lbs (it needs a diet).

Using the generally accepted formula >>> hp= (trapspeed/234)^3 * weight <<< it shows my car should require 292crank hp to reach that mph.

I have just shown you an instance where a dyno shows the same number as real life within a small window of error. You shouldn't believe all dynos lie.

-Dana

333pg333

^Isn't that based on a lot of other things though Dana? Driver, traction, wheel pressure, suspension, skill whatever....just because you got 102mph. Someone else might have got 110mph or 95mph? Or am I missing something here...?

asiancaucasian

Hi Dana,

I'm actually at a similar elevation to you as well. My dyno operator says the 413whp number on the Dyno Dynamics was uncorrected. My dyno operator for the dynojet run says it was with an SAE correction whatever that means?

Rogue_Ant

Trap speed is a pretty good indicator of HP. ET is much more representative of skill, traction, ect.

Rogue_Ant

That is why their is a discrepancy between the two... The correction number should be something like 1.10 or or so. This means that they multiply your uncorrected HP number by the correction factor to get the corrected hp number.

333pg333

I'll take your word for it, but it does seem like one would totally influence the other. If I have a poor ET surely that's going to effect my trap, no?

Rogue_Ant

Some, but not as much as you might think. You could do a 15sec 1/4mi @100mph, due to spinning and slow shifting. But that same 100mph might get you a 13sec 1/4mi. The difference is how well the car launches and your shifting. But both cases the same HP.