I did my first dyno run today at House of Power in Hungtinton Beach. I never had the car dynoed since the supercharger install, so I was curious to see what the car would put down. My current mods to the engine besides the supercharger are Spec Stage III Clutch, Fabspeed Headers, Fabspeed Exhaust. We did a 4 gear dyno pull.

We ended up with

Horsepower

370.43 RWHP translates to 445 HP to the crank

Torque

279.07 RWTQ translates to 335 TQ to the crank

 

nice numbers... thats stock tt territory

 

445hp with a 3.4 engine...not too shabby!

 

RWDRIFTC2: What programer raised the rev kimit to 7500 rpm? .

 

VF Engineering uses GIAC

 

Looks like a great readout Vince. Good job!

 

Also, are you running a modified exhaust system? Your torque number is very low at 5K rpm. It should be at least 20% higher. You might want to check your resonance valve operation. There is something definately wrong as your torque and HP results are below stock up to 5K rpm.

 

RWDRIFTC2 what header are you using? and also what exhaust. please pm me and i can tell what exhaust caused me to lose HP an TQ. I'm not sure if they are a board sponsor so i don't want to say anything bad about them.

 

that's what i got out of my 3.4 (in 4th gear) with completely stock exhaust and the rev limiter actually lowered 200 rpm.

 

I am running full Fabspeed. I have the Fabspeed Exhaust, Fabspeed Headers with the supercharger.

 

Well, the exhaust would definately lower your bottom end power. I am running stock exhaust and my torque is 50% greater than you are showing. Do you know what size pulley you are running on the blower? Your chart shows 6psi at 7500 rpm which would translate to about 2.5 psi at 4K rpm.

You will notice that your power does not come in until your fuel/air ratio starts to lean out from a way too rich condition before 6k. I would guess that you need to lean the engine out a little more to help get back the low end power. There is nothing you can do with the power lost due to the exhaust, unless you put the stock one back on. If you're looking for performance at the high end, then stay with the Fabspeed, but unless you plan on keeping the revs above 6k, you're not seeing much more than stock with the current F/A ratio below that point.

Also, simply going by the chart, the big fluctuation in power at around 5600 rpm makes me believe that your resonance valve is not operating at the correct time. The stock setup should have the valve open from idle to 3100, closed until 5100 and then open for the rest of the time. It looks like yours is opening at around 5600 causing the drop and then kick in power. Changing thie operation of the valve will give you a smoother, more predictable power curve.

I would be curious to know the readings of your fuel trims (long term), your MAF reading at idle with no air conditioning running, idle speed, secondary O2 sensors at WOT and timing at WOT. The MAF reading will do the most to help determine why you are running rich at the low engine speeds.

 

I am currently boosting 6 psi. I also noticed that my car is running really rich until higher RPMS. I am defintely going to take it back and get some more programming work done to compensate for my mods. Hopefully with a new program I can clean up that mid range area. Thanks for your insight and help with analyzing the dyno chart.

 

You probably don't need a new program, just a few adjustments you can do yourself if you do any work on cars. If you have a scanner, give me the reading I requested above and you might be able to correct the problems in your driveway in an hour. If you don't hae a scanner, you should get one cuz it's the most important tool you can have for a modified car. Cost about $150.00. Make sure it provides the following info:

MAF
Long Term and Short Term Fuel Trim
O2 sensors
engine temp
engine compartment temp
timing
engine load

 

Are you talking about an OBD II Scanner? Which one do you recommend? I have an Autoray right now, but it does not map all those parameters. Also I have not put new spark plugs for about 2 years. Do you think that would also be a problem? Thanks again.

 

Yes, an OBD2 Scanner. I have a PC based software which is not available anymore. If you do a search, there are many good one's that are available. I think autozone has one. Make sure you don't just get one that reads and resets the codes, but shows the parameters I listed.