Interesting and good to know. I expected some decrease because of the better flow and less restriction but I guess that the engine internals are the only thing creating the pressure.

 

nice numbers dog, that 500 crank HP@15% driveline transferrence. the TQ hasn't changed much in peak but you gained a bit of area between the curves.

wish i had a 3.6

 

yo dog, can you overlay the boost data over you dyno? would be a let's see for "****s and giggles" kinda thang

 

I'm not that tech savy and it wouldn't really blend well. I can post a screen shot of my zeitronix data logging though. Or I can send the before and after data log files to anyone that wants them. The zeitronix software is free and relatively small so it's easy to view them. The logging period is short as I only acitivated it before and after each run. The RPM sensor isn't hooked up yet, but you can see TPS, EGT, AF, and Boost. Either way.

 

In reality, Dog has increased the amount of time it will take his car to get to 100 mph from any speed below 50 mph. What he will find is that he has moved his power to a higher RPM and has greatly REDUCED the power available for his 2nd gear shift. His 2nd gear shift is now into the weakest part of the power band.

 

I came up with about 489 I'm almost near that magical 500 mark. We're actually doing a few small changes based on the AF ratios. I'm running fairly rich at WOT throttle: high elevens, to 12 flat. Mostly in the 11's. From what I have been told, 12.5 is optimal on our cars at WOT under load.

I should be over 500 shortly with a little bit of tweaking

I wonder how much longer the clutch is going to last??? Seems like there are always bad smells when you are really hard on it for a while and then stop

 

if you say so... first and second feel brutal at this point. when i do my 1-2 shift it usually dumps me right back into the meat of the power band. my car never impressed me below 4K anyway. maybe you shift too slow

 

You are imagining things DOG. The fact is that you are shifting into the 4,000 rpm range when going into second. Your increased exhaust flow has reduced the power available at that engine speed whether you shift fast or slow. You can't simply increase overall power to the engine and expect better performance without taking alot of other things into consideration, including the gear ratios. Had you documented some times on the street, the difference would be pretty obvious to you.

 

Whatever... I must need to go back on my meds anyway I'm seeing pink bunny's and improved performance on my car.

I see what you're trying to say, but it doesn't really feel like I'm losing anything for that split second I'm at 4K as it moves past there so quickly, which I'm sure is compensated by the increased performance past that point.

It feels a little quicker under boost. And it seems like it boosts a little quicker too. Imagination or not... I'm happy with them.

Like I said before, these cars are about useless under 4K, blown or not. My only perceived power (blown or not) was between 4 and 7.2K. Since you can't have it both ways (more power and torque on top and bottom) with exhaust tuning, I'll take it on top where my car performs. Why add to the bottom and rob the top where the car really makes HP.

 

Having no power below 4000 rpm is a result of your setup. Too much exhaust flow for only 2.25 psi of boost at 3600 rpm. You now have less torque at 4000 rpm than the standard 3.4 EVO setup and since you MUST shift into 2nd gear at or below 4100 rpm, you are always effected by the powr loss. Additionally, although your power is higher at higher rpm's, the increased power is far less than your loss at the bottom end and won't negate the loss untill your 4th gear shift.

And you CAN have it both ways with the correct setup.

 

Let's not lose sight of things here. This is not a race car. This is DDog's toy. "Real" increase in "performance" or not he likes it. End of story.

 

My car had no power below 4K stock. None of these cars do, especially 3.4 liters. My loss in the low rpm dip was about 18. My gain at the stock 5K dip was about 27 with a peak gain of around 9. I'm not asian, but I can do simple math. Looks like I gained more than I lost

What would be the correct setup then? I am assuming you have it. Would you please share it with the rest of us as I would love to know about a better header/muffler combo? That would be nice

 

There is no REAL increase in performance. He is claiming 25 - 30 hp increase at a specific rpm. Why not brag about the areas in the power curve where he lost power? A car's performance is a result of the entire power curve and not simply a specific point in the range. And since his setup forces him to shift into the weakest area of power, this loss drirectly effects the cars performance.

You cannot simply increase exhaust flow on a non turbo car and not expect to lose power in the bottom end, and the bottom end effects the overall performance of speed than does the higher end.

 

I said from the beginning that there was a dip for about 3/4's or so of an rpm in the bottom.

Ok. You win. My headers suck and my car is slow

Just please enlighten us all on the proper setup so I can quit throwing countless dollars away on improper equipment. You seem like you know what you're taking about so let us all know what you're running and what kind of performance you got. Thanks in advance

 

Your drop in power at 5500 is a result of 2 things; one being your timing being pulled back when the variocam shifts. This drop is a one time event when racing your car. Once the variocam shifts, it wil not go back until load is removed from the engine for several seconds. Therefore, in reality, after the initial dop in timing in first gear, there will be NO pull back in timing during the rest of the race. Once again, real world testing would show this clearly. So, the results of your dyno that show a 27 hp increase is valid only if you start your car in 4th gear at a low rpm and go through the rpm range. You TRUE power change is calculated by averaging the loss in power BEFORE the dip and the gain in power AFTER the dip. Net gain = ZIP.

By the way, I am not intending to riducule you or in any way degrade your mods, but simply pointing out the fact that your claim of power increase is wrong. Only if you maintain your engine speed above 4500 -5000 at all times will you see a modest gain in power with your headers compared to the stock ones.