<Puck>

While 5rwhp may very well be in a margin of error, 10 to the wheels is significant. By your logic, seemingly everything save for LT's,ported heads, cam, and nitrous are not worth it, since they will only add the possible margin of error or so.

Not much will get you 10 to the wheels after basic mods. I would gladly pay quite a bit - much more then what a mail order tune goes for - for a consistant 10 more rwhp.

SS RRR

You're funny. Seems you'll grasp at anything for the sake of argument.
The weather had absolutely nothing to do with the gain. It's as if you think I've only ran the car with certain applications one time in different weather conditions. Don't be stupid.
Before the LT's were on the engine the car was dyno tuned with a wideband by Ed Wright at his shop in Oklahoma. He spent the better part of 5 hours with it and that tune has been used as a baseline for several other cars with the same application so the tune wasn't off. With your line of thinking I guess I should've started a trend and announced to everyone here to get a FastChip tune first and then LT headers because the gain will be substantial because the tune is slightly off and LT's will be more beneficial to an engine that has been tuned for another appliation. Where's the retard smiley icon when you need it...
You can take those minor gains if you want. I just can't say with a clear conscious that I gained 5rwhp doing "X" mod.
What you are missing here is my gain is more than likely higher due to the difference in mods. However from past members posting who've done the bolt-on/stock exhaust to LT/ORY mod their gains have more than 5 or 10rwhp and definately better than 1rwhp.
Anything else you'd like to argue or pontificate?

SS RRR

More power to you!

Z-RATED94

Thanks for the clarification.

Jeremy95TA

So basically it seems that I'm around where I should be for power with the 9". I'm guessing that the 9" has about the same drivetrain loss as an auto then.

Yes, the 9" is a bit overkill right now. However, everything I do to my car is built with a final goal in mind. My goal is a H/C/N2O 383. Plus I want to keep it a 6 speed so I plan on launching it HARD. I already dump the clutch at about 5500 RPM's and thats off the bottle. When I put the bottle on its going to hit much harder.

For the record, I've got a friend with a 12 bolt 6 speed 420 rwhp LS1. He's broken 2 posi units and bent a 31 spline axle. The shop that did the work warrantied it all so that was a good for him. However, 12 bolts are just too weak for 6 speed cars. M6's are just too violent. Especially with how hard I plan on launching the car. Not to mention that I have a McCleod Street Twin so the clutch slipping shouldn't be in issue.

SS RRR

Even with the 9" it doesn't explain why your gain was nothing when you went LT's w/ ORY. Maybe it was a bad dyno day and the track will tell the story.

Jeremy95TA

Well its not exactly no gains. Remember, I had 260 rwhp no 9". Now 9" and boltons and making 268 rwhp. So I have 8 more rwhp than I did when I first got the car. I know that 9" is eating power. I just didn't know how much. You said it though, we'll see if I can get better than a 13.8 at the track.

Z-RATED94

The proper way to build the car is the way your going about it. No sense in having decent HP if the car can't take it and you keep breaking parts. That's the route I took. Minor bolt ons at first, while I starting installing suspension parts, sub-frame, etc. Then started saving for the H/C swap, and all the associated parts that go along with that.
And as you mentioned, 12 bolts aren't as strong as some people think, when it come to manual cars that launch hard.

neat

I think you're pretty much right on the money. I work in a speed shop and dyno cars almost every day and your numbers don't sound off to me. I can't definitively say what the 9 inch costs in power as compared to a 10 bolt, but I'm sure it's something.

I can almost guarantee 10 RWHP out of a tune on a stock car, 15 or so is the average. A little more if you've got some minor mods like longtubes, rockers, CAI, etc...

I agree that there is some variance on the dyno from run to run, but if the car is up to temp and running properly, the difference is usually pretty nominal. On my dynojet 224, a stock LT1, M6 will almost always (9 out of 10 times) make within 2 or 3 HP from pull to pull. I tuned one a month or so ago that was having some software problems with the computer, it took me forever to figure it out and I probably made 30 pulls with that car. As long as the car was up to temp, all the numbers were within about 2 RWHP. You'll see some bigger variances if you run the car cool and then hot, but if the engine is the same temp from run to run, the results are usually repeatable to within about 1.5%.

I have seen some greater differences from day to day though. I can dyno a stock LT1 car, repeatedly make 275 RWHP, and then let the car sit for a week without touching it. Strap it back down and have it make 10 RWHP more or less than it did last week. The software is supposed to correct for weather, but I don't think it's realistic to expect it to be dialed in to 10th degree. From pull to pull to the repeatability of the dyno is excellent, from day to day... don't get worked up over 5-10 RWHP. If you make a pull, and then immediately make another pull and lose 10 RWHP, you've most definitely got some looking around to do, but if you are 10 HP off from what you made last week, month, year; I don't think you should be worried.

That being said, a 5 RWHP gain on the dyno is pretty borderline to consider a legit gain, especially if it only shows up on one pull. If I make a pull, and peak power is 270 RWHP, then I make a change and the peak number goes to 275; you can usually tell if it's a dyno squiggle VS a real gain by how the graph looks. If there is a ramp up to the 5 HP gain, or the gain is across the entire graph, chances are it's legit. If you can repeat the 275 number then it's almost 100% certain that it's legit.

Good luck with the car, I don't think there is anything wrong with. It most definitely could benefit from a tuning session, but I don't think there is anything really wrong with your dyno numbers.

<Puck>

Well said.

dangalla

wow i never thought i would be agreeing with mr. ss but where is that retard smilie....

neat

I'm not sure, but I think you might of just called me a retard, lol.

I guess I could qualify/quantify my statement about gaining at least 10 RWHP, and 15 on average with a near stock LT1. I've probably done 100 or so tunes on stock-ish LT1 cars, and pretty much every time the cars pick up at least 10 RWHP. Sure there is the odd duck that won't pick up much, but 9 times out of 10, 10 RWHP is almost automatic with 15 being the average.

I'm not saying that any dyno tune from any company will pick up that much, that's just been my personal experience. I'm also not any kind of tuning guru or anything, the only real thing I have over most people is access to a dyno. The first 10-20 LT1 cars I tuned probably took me 20 pulls each to get dialed in to what I thought was maximum HP output. I can usually hit it in less than 10 pulls now, but it still takes more from time to time. It's also entirely possible that someone else could pick up more power than me. All I usually do when tuning for power on a stock-ish car is lean it out some, take the bumps out of the A/F ratio, add timing at various RPM's until I get KR, then back the timing off about 2 degrees from KR. I might go 3 or even 4 degrees back from KR if the power doesn't start to fall off, or the customer wants to put 87 octane in the car. Normally those changes add 10-15 RWHP, sometimes more, and very seldom they will add less or none at all.

Z-RATED94

Nice! And what kind of tuning experience do you have? Do I totally agree with neats #s, of coarse not. I wasn't there to witness his results. Do I think he's way off base, no. And if you don't think a car with some mods can pick up between 10 to 20 HP with tuning, then yeah, you should be agreeing with the other guy.

dangalla

pay attention we were talking about a car with NO mods, of course tuning a car with mods for the mods is going to help slightly depending on what exactly you are talking about. but 5-10 is practically nothing and you can not rule out the fact that engine temp, iat, and many other slight factors could add up to your "10hp" gain

your the type of clown that hypertech makes its money off of doing the 160 thermo and "tune"

Z-RATED94

I'm talking minor mods as was the oringial post. As far as tunes, my start up tune was from Ion, for the H/C swap, and was touched up by Speed Inc, after the swap from shorties to LTs. Hypertech, yeah I have one from back in the day when there was no tuning yet. Fans and thermo done, plus th speedo was adj. for the gears.
So i guess neat is lying, and I to am a retard. That's cool. Take care.