Direct Scan ?

[IrvJr]

How accurate are the HP and Torque values given by DS? I put in all the info as accurate as possible, and was wondering if anyone has compared them to a dyno values?

Scott

 

[crash]

We ran the DS about a year ago on a Dynojet chassis dyno with a fairly stock GN. 19 lbs. boost, open exhaust, K&N, custom chip. I forget what the HP/TQ #s were but the DS was within ~3hp and 5 ft/lbs throughout the run. We were all very impressed. I believe you would need no wheelspin to get correct results.

 

[IrvJr]

I would like for the numbers to be close. But i am sceptical because they are very good. Are they supposed to be rear wheel figures or flywheel?

Scott

 

[J Banning]

My DirectScan numbers are all over the place. I run a 28" tire and set the preferences in DS accordingly...

401 hp & 450 lb-ft @ 4675rpm in 1st gear

then...

166 hp & 167 lb-ft @ 5200rpm in 3rd gear


I think I ran a 11.72 on that run, WTF?

-Banning.

 

[BM Computer Src]

The DS just calculates those numbers, take them for what thats worth. I would suggest using the DS for the other tuning you can do with it, with the real / good values it has. BUT, if DS shows some obscenely high HP and torque numbers, be sure to save it to impress the saturday night car show curious guys who ask, what does this thing put out?


Bob

 

[IrvJr]

My numbers were very similiar, high at 3300 rpm and low at 5000 rpm.

Thanks guys
Scott

 

[J Banning]

What, 166 hp at the top of 3rd gear isn't good?



I had always heard, and I think it even says so in the manual, that the HP figures aren't really accurate. Instead, they should be used as a tuning reference... observe the numbers and at what RPM/gear they happen at, make some changes, then look again to see how the changes affected power output at the same RPM/gear.

Hope that makes sense.

-Banning.

 

[Weazel]

Hey, my 13 second sled makes over 450 hp and 550 ft-lbs of torque!!! Haha, at least that's with the wheels spinning. You definitely have to be planted to get good numbers, the wheelspin makes DS think your car's rocketing away.

As for the weird numbers at the top of 3rd, I may have SOMEWHAT of an explaination. If you ran a high-11, you were probably doing 110-115mph at that point, right? At that speed wind resistance is huge, especially on these bricks. DS takes the weight of the car and the instant acceleration and gets horsepower from that. It doesn't account for wind resistance. So at a steady speed DS will read 0 hp, and we know that's wrong since power is needed to overcome air resistance. At 5200 rpm in 3rd gear the car is spending a lot of HP overcoming wind resistance, and 'only' has 166 "left" for accelerating the car.

 

[IrvJr]

Thanks guys, all this makes sense.

Scott