bent1

before latest mods: prc stage I heads, MS3 cam, 42lb injectors, ls6 intake, long tube headers, 3" y-pipe, stock intermidiate pipe, magnaflo muf, stock tail pipes.
Dyno=405rwhp/363torque

today added: Fast 102 with Fast fuel rails, 102 tb, no MAF and running speed density.
todays dyno=406rwhp/360torque
Are these heartbreaking results due to a bad tune, restricted stock intermidiate pipe and tail pipes or could it be something else? This latest mod was very expensive for me to get no results. Can anyone help me figure this out?

WarShrike

iTrader: (5)

Do you have the graphs? Peak #'s honestly aren't as important as where it happens and the amount under the curve.

Did you do this on the same dyno as well?

gnx

need to see dyno sheet as you may have gain 30 under the peak which maybe huge/ plus did you use the same dyno they show different number it is just a tool/ you should of dyno it then went back and did it again on the same dyno if you did not go to the same place.

Jenson

iTrader: (32)

Adding a fast 102 usually doesnt pick up much under peak, more top end. I would definitely add a cut out after the Y pipe, should easily pick up 15 with your setup regardless. A lot of other factors like weather, different dyno, different wheels, tires, gear and all that will effect the numbers. We need more info.

bent1

Yes same tuner same dyno. Its a 6m, ford 8.8 diff and it was about 91 degrees F

bent1

Ordering cut out today

Jenson

iTrader: (32)

Who tuned it? We are saying that if you dyno'd the previous setup back in Jan @ 40 degree's, you'll see a drop to the 91 degrees run typically.

WarShrike

iTrader: (5)

That's if they aren't doing any SAE correction.

bent1

Just to update, I havent been back to the dyno yet but I will post the dyno numbers as soon as I get them. I had developed an oil leak with the last dyno run and have it apart waiting on knock sensor grommets. The catch can was connected backwards also.

bent1

Sorry it took so long to get back with you all. I was only able to do two pulls today and heres what I got:

418rwhp/367torque

It still seems like I should be doing better than this. I still dont think the Fast-102 with T/B has done anything for me except take my money. I cant figure this out. The outside temp was 99F though. I have the dyno sheet if it helps to figure this out

cbr600rx7

iTrader: (12)

12 hp gain is not all that bad on that set up in hot weather. The LS6 can support 400whp very easy so i dont think it was hurting you at all. Also why did you go SD so soon when the factory MAF can handle over 500 to the wheels? What size is the exhaust that runs from your Y pipe to the muffler?

bent1

It has long tube headers with a 3" y-pipe into the factory intermiediate pipe where the cut-out has just been installed. I did away with the maf because it was so much smaller than the 102mm Throttle body and figured it would be a restriction.

djfury05

iTrader: (30)

I've personally seen a friend of mine make 418 rwhp with the MS3 cam and long tube headers, still with the ls6 intake and untouched 241 heads with t56 and 10 bolt, something isn't right in your setup IMO.

What's the valvetrain consist of?

bent1

yes exactly. Thats my dissapointment and I agree with you. It should be doing a lot better than this. The vavletrain consists of ls7 lifters, harden push rods, 650 dual valve springs, factory rockers.

bent1

I would really like to figure out why i'm down on power but I'm out of ideas. I really dont think its the tune because this tuner does this everyday for the last seven years. And well, hes also a good friend of mine and I dont want to think its the tune. I dont know much about tuning but he says, "making HP is the easy part. Its the driveability is where it gets more difficult." Would most Tuners agree with that statement? Well one more thing. I have the factory fuel pump. Is there still enough fuel pressure for my application? I would think the Tuner would notice a fuel problem though. If anyone could help me figure this out I would be very thankfull.

Blk98Vert

iTrader: (2)

As long as the wideband doesn't show a difference in AFR throughout the pull it shouldn't be an issue. But to be safe have the pressure checked. His attitude sounds like its more of a street tune, which will show less than a dyno tune pretty much everytime. As far as your exhaust I guarantee it is killing you, at least get a full catback if not true duals. But even with the exhaust that setup would still respond by a large amount on the top end. I know you dont want to hear this but its the tune. There is no reason a little 224 cammed LS1 will gain around 15 peak and your setup gained the same amount

bent1

Even with the cut-out you think the exhuast is still restrictive? And he does do the tune with the dyno. I should consider the tune is where most of the problem is? Thanks for your input and everyone else

Blk98Vert

iTrader: (2)

The Y merge is where the power is going to be, what kind of y pipe?

bent1

Its a 3" Y-pipe. I think its a Headman Y-pipe

djfury05

iTrader: (30)

I bet if you put a quality y-pipe and intermediate and back you will pick up 15-20 easily