Dynamometer Results & Comparisons - Is 320 RWHP realistic or optimistic?
11-08-2005, 07:26 PM
I've finally gotten my headers installed (Hooker LT's) and am heading over next Wednesday to get tuned by Jeff Creech. I know that tuning at this point isn't absolutely necessary but my car started breaking up a tad after the header install so I just want everything right. I've got the aforementioned headers open with no exhaust, LS6 intake, 85MM MAF, MTI lid and an ASP underdrive pulley. Car is an A4 with a PT4000 converter and a Moser 12 bolt w/3.90 gears. I'm running wrinkle wall Hoosier tires and I've heard that they cost quite a bit of HP on the dyno as well. Am I about to be sorely disappointed when I see the dyno numbers? Maybe I should put the stock radials back on for the dyno session??? The car has run 7.58 and trapped 89.9 MPH in the 1/8th so the track numbers are decent but I want some dyno numbers to throw out at people as well. Any thoughts? Thanks.
11-08-2005, 07:40 PM
I am going to say 320RWHP is conservative, and is pretty realistic.
11-08-2005, 08:01 PM
if it was a 6 speed and you still had the factory 10 bolt the i think you would be right on those numbers, but since you dont i say around 300-310.
11-08-2005, 08:08 PM
As a quick point of reference, it put down 308 to the tires through the same 12 bolt but with 3.42 gears when the guy owned it that I bought it from. I've added the underdrive pulley and the headers but changed to 3.90 gears from 3.42. If I put down less power than when he had it, I'm gonna be pissed. Aren't headers worth 20-25 horsepower when tuned even on a completely stock motor? I know the dyno numbers on an A4 suck though. Somewhere on here I've seen an A4 that dyno'd at 304 running mid 11's @ 116 or so in the 1/4 mile. That being said, it sure would be nice to say I've got 325 horsepower and not have to lie about it. :)
11-08-2005, 08:19 PM
I think you'll hit 320, maybe even a little better.
11-09-2005, 12:38 PM
I think your answer is yes and no. Yes you should have more then 320 rwhp but not through that converter (unlocked). I had my car dyno tuned and it only makes 298 rwhp. Now I'm thinking WTF, only 298 with LT headers, ory, lid, ported TB, ect. But then I was told that the pulls were with the 3500 stall converter unlocked. I guess to dyno the car locked for the bigger number is dangerous and I would have to sign a release form (which I ultimately declined).
The guys did tell me that they estimate I was in the 325-330 rwhp range (had I run it through a locked converter). I trapped a solid 109.50 which indicates to me that they were about right. My 1/8 trap was around 86 so you would probably be surprised at how much power your making with your car trapping almost 90 in the 1/8.
It's not just the transmission eating our HP. It's also the higher stalls and higher STR. But as long as the ET is there then so be it I say.
11-09-2005, 04:52 PM
you should be right around there.....i put down 335/350 with a catback,lid and maf through a 10 bolt and stick
11-10-2005, 03:09 PM
I doubt you will hit 320rwhp with a 4k stall locked with just bolt ons.
But for reference, my friend Kevin made 333/353 with his 4k stall unlocked. No pulley, LS6 intake, or MAF either.
11-10-2005, 03:52 PM
Change tires. 320 is possible, but with a stalled A4 with a 12 bolt & those tires it may not happen.
11-15-2005, 06:45 PM
Well, tomorrow is the big day for me. I'm heading out at 3AM so I can get to Durham and be ready for my appointment at 10AM. The Outer Banks is so far away from everything. :cry: Anyhow, I ran the car one more time and got a 7.53 @ 90.05 with a 1.604 60' time and a 4.80 330' time out of it. It's going to be interesting to see what power the car is making now and what improvement, if any, can be had from tuning. I'm taking race gas with me so Jeff can tune a little more aggressively than on the average street car. I don't really drive the car around, especially with the open headers so I'm going to try to push the limits of tuning on basically a stock motor. I'll post up the results (maybe even from Jeff's shop) if case anyone out there with a mostly stock setup like I have can see what improvement can be had from a tune. Have a good one. :)
11-16-2005, 03:39 AM
I think truly you do have 320 and more, but your car may not show it due to the drivetrain mods. Don't know what year your car is but my 02 made 311/320 stock through an A4. I am sure with your LTH and such I could have made 320+ with my stock drivetrain. With the set up you are doing I would only concern myself with dyno tuning and track times to demonstrate the cars true power.
11-16-2005, 09:08 AM
I'm sure you'll have a good experience with Jeff - he is the man. :)
Let us know the results!
11-16-2005, 09:36 PM
Long story short: The car made 328.9 horsepower at the wheels. Not bad me thinks considering all the liabilities I had. It baselined at 314.5 so that's what it had on the 7.53 @ 90.05 run. It's not just the peak that I'm pleased with. There was a hole in my powerband about 500 RPM wide that Jeff took care of. I've gained about 25 horsepower there. I don't remember how to go to his site and post a link to the graph but it looks way different than a manual tranny graph and even much different than those with a smaller converter. It basically just hits whatever power it's going to make as soon as you stand on the gas and stays there the whole run. My A/F ratio is floating between 13.8 and 14.5 the whole run. Jeff told me to make sure I mentioned that I had open headers during this tune so it's a lot leaner than if I had full exhaust. Now to the track tomorrow night to see if the 15-25 horsepower I've gained across the board will translate to much improved times and MPH's. Before proceeding I'd like to make a statement. My car is heavy as crap (~3700 pound raceweight) even though the passenger seat is out of the car. Comparing what my car is running to another car 500-800 pounds lighter than mine really isn't fair. That being said I've run a best 60' of 1.604, a best 660' of 7.538 and a best MPH of 90.05 in the 1/8th. I've yet to run a full 1/4 with this car. I'm hoping for at least the following new bests given my new power curve. 60' of 1.53x, 660' of 7.39x and 92 MPH. I know I could snatch 800 pounds out of my car and easily better these times I've set as a goal but that's just not realistic at the moment. I'm hoping to run respectable times with a full or even overweight car. Results to follow once I get back from the track. I'll post about it in the Drag Strip Results forum.
11-17-2005, 10:35 PM
Glad to here Jeff was good to ya. He seems to know his shit on these cars. I was hoping to get mine to him one Sat. but he just laughed and said maybe around Feb. he would have an opening. Looks like I'll just have to take off work one day.
11-18-2005, 12:18 PM
Even though there may be a long waiting list, it's worth it to take your car over there. Unfortunatley, I destroyed my tranny so I didn't really get to see the performance gains that I should have. The tranny had been shifting kinda slow on the 2-3 shift the last couple of times at the track but I thought it would hang in there. Oh well, the increased power definitely showed up in the 60' and 330' times.