GIAC FXK03 dyno...question about peak torque.

**gdawg'05a4** · 09-16-2008 08:54 AM

So I got my car dyno'd finally. I was curious to see what the numbers were.

169awhp @ 4800 RPMs
194awtq @ 4500 RPMs

I noticed compared to other dyno sheets that my peak torque is quite late in the power band. Other dyno results I've seen almost are at peak torque around 3000-3500 RPMs for BI setups, definitely a big difference compared to mine. The guy running the dyno said I would probably benefit from a larger DP (currently stock DP, which I think is 2.25" to custom mid-pipe back, 2.5") and a TIP. Assuming my car is running fine, what could be done to move that peak torque to hit earlier.

Two others to compare, both also GIAC FXK03, similar mods minus a DP.

**TurboQuattroPwr** · 09-16-2008 10:10 AM

I put down 176awhp on Autospeed's dyno two months ago, so I guess your numbers are in line with that.

**gdawg'05a4** · 09-16-2008 10:11 AM

Yeah the numbers are pretty much spot on for the setup but peak torque isn't compared to others. It's slower at getting there.

**b5s4tt** · 09-16-2008 10:33 AM

downpipe will definately help

**mike-2ptzero** · 09-16-2008 10:37 AM

Were the other cars running a FMIC?

**gdawg'05a4** · 09-16-2008 10:39 AM

The first one, yes, AWE FMIC. The second one, not sure. It only looks like one run was done or they took the best out of 3 runs.

**actlsub9** · 09-16-2008 11:00 AM

How about a boost log of your car.

**RLB6** · 09-16-2008 11:09 AM

I think these dynos were performed in different gears than each other. The dynos' your comparing too were done with cars that have 5 spd tranny's while yours is a 6sp. So again, the difference is in which gear these dyno's were done.

**b6onboost** · 09-16-2008 11:15 AM

You should see near peak torque beginning at ~3000rpm and then it plateauing until about 5000rpm. At 3000rpm your graph is only showing 125ft/lbs of torque, while the other graphs are showing both showing about 160ft/lbs.

Looks like you are not fully spooled until past 3500rpm. The K03 should be spooled well before that. It looks like a much more gradual torque curve than most BI dynos have shown. Might be a dyno issue, might be your car.

When you drive the car does it feel like the graph indicates?

**gdawg'05a4** · 09-16-2008 11:30 AM

Originally Posted by actlsub9

How about a boost log of your car.

I'll see if I can dig one up. I did one about a month or two ago and requested vs actual was in line.

**gdawg'05a4** · 09-16-2008 11:31 AM

Originally Posted by RLB6

I think these dynos were performed in different gears than each other. The dynos' your comparing too were done with cars that have 5 spd tranny's while yours is a 6sp. So again, the difference is in which gear these dyno's were done.

True, I forgot about that. Mine was done in 3rd gear and the others were as well IIRC.

**gdawg'05a4** · 09-16-2008 11:33 AM

Originally Posted by b6onboost

You should see near peak torque beginning at ~3000rpm and then it plateauing until about 5000rpm. At 3000rpm your graph is only showing 125ft/lbs of torque, while the other graphs are showing both showing about 160ft/lbs.

Looks like you are not fully spooled until past 3500rpm. The K03 should be spooled well before that. It looks like a much more gradual torque curve than most BI dynos have shown. Might be a dyno issue, might be your car.

When you drive the car does it feel like the graph indicates?

The car pulls hard from about 3000+ (not like the dyno indicated), almost like it spikes and pulls to 5000 or so then runs out of breath.

The gradual part was what caught my attention and the guy doing the dyno.

Someone suggested I swap out my DV, still on the factory one but not showing any symptoms of a "bad dv". But I wouldn't think a DV would help that curve.

**RLB6** · 09-16-2008 11:46 AM

Originally Posted by gdawg'05a4

True, I forgot about that. Mine was done in 3rd gear and the others were as well IIRC.

2003 5 spd 3rd gear ratio: 1.429:1 , final drive: 3.889:1

2005 6 spd 3rd gear ratio: 1.423:1 , final drive: 3.889:1

You're 3rd is not as aggressive but not different enough to cause your power to come on so late. Maybe a DV problem?

**gdawg'05a4** · 09-16-2008 11:58 AM

Originally Posted by RLB6

2003 5 spd 3rd gear ratio: 1.429:1 , final drive: 3.889:1

2005 6 spd 3rd gear ratio: 1.423:1 , final drive: 3.889:1

You're 3rd is not as aggressive but not different enough to cause your power to come on so late. Maybe a DV problem?

Yeah, someone suggested a DV problem. I'm going to order a replacement DV seeing as mine is still the factory one. It's been through about 70k miles on just a GIAC flash and then BI at 84k. Currently at 99,xxx miles.