And i was the gunni pig. I will say that something (still hammering away at my mind) why with the setup that i had with the installed cutouts (right before the cats) I lost time. i averaged 2.2-2.4 for 60' and i usually get 2.0-2.1. Now i have looked into this "back pressure" thing and I am pretty sure that someone one day just coined the phrase on some forum and that was it. everyone was satisfied with it. I am more than sure it has to do with tuning the exhaust for the pressure waves.... and believe me they are strong. The shook the cab down the track every time. I will say, however, that just having the ability to pull off these little mettle plates and having the ability to turn on my truck and set off many car alarms in the waiting lane was quite entertaining. It also feels like im driving a dragster down the strip with vibrations. Anyways. Tunners can you tune a chip for open cutouts if i give you the tube lengths of each exhaust valve to the opening? I have JBA headers infront of the cutouts. Now I did do one run with the cutouts closed and i didn't get a much better time. My 60' was still 2.2 and my time wasn't the best for the night. So i have no idea

 

I would say that opening up the exhaust is hurting you on the low end power when your taking off, I thought it would show up more on the far end of the track if anywhere. What were your 60' times before you started all of this. I wouldn't be happy at all if I just done all the work you have just to end up with a 2.2 60'. Heck I'm getting 1.83's now on my F1's and a stock exhaust. Good Luck my friend.

 

Doesn't sound like an exhaust problem if you 60' times didn't improve when you capped them up. Sounds more like a traction problem. Plenty of people are running straight pipes with no problems.

 

Straight pipes, and they still have torque???

 

Well, not much help on the exhaust thing, but it did seem to me last night like the track was not hooking up very well?

The run I made next to you last night, the truck hooked pretty well, but the second run I made (next to SVT150 on the plate)
was utter crap!
I spun really bad, and I feathered the throttle a bit on that run as well...

May be why your 60's were high? (Mine were bad! 2.2, and 2.3)

From my previous posts, I am a newbie, but even my friend who was driving the Z last night (and he has raced many times at SW) said the track wasn't hooking as well...?

BTW, your truck was LOUD with the open headers!

Sounded like a B.B. ! Lol...

Good luck in your quest!

 

thanks yall but to my utter dismay the whole project will be put in the back of my mind as putting in new cats. with a little bonus. I will test it capped all next week and i should have my chip by then but im going to run without the chip in first so we will once again test the tunners. But now i just have the ability to set off EVERY car alarm at the ASU parking lot.... hehe 4 stories of overly senitive cars.... ooo it's going to be good. Also for anyone that tunes exhaust could you help me out a little. I need to know how fast the exhaust gas flows out and how fast a rebounding vacuum wave would flow BACK in. I dont want to burn out my valves. I checked it today with a long piece of tin foil and there is a substancial amount of back draft. Also, how would i know if i have burned out a valve?

Thank

Mark

 

I've seen cat-pass pipes like yours, but hooked to a valve. The valve has a 5' steel line that can be mounted in the cab. When you want to go to straight pipes, you just pull on it. Push it back in to go through your cat/mufflers. That may be a good thing here. Start out on regular exhaust, get into 2nd gear and then go open headers

 

hmm.... i saw that but they didn't fit... but i didn't think about opening it up once im at the higher RPMs...... thinking. It will be something to build and take up my time in college. it's not as though im learning anything... yet. i hope. Ill get back to yall on that Brian you might have spawned a new creature.... or at least something that i could yank on when im next to a car at a red light... hehe

 

Spade$,

Hmm, seems like I remember some guy last week at the track telling me he was gonna do this cutout project, and I remember telling him he was gonna run way worse. He told me, yeah, I'm gonna put these cutouts on and beat all you guys! Do you think maybe I knew something that guy didn't?

Not to sound rude, but the 2nd gens have been out for 2.5 years now, and do you see a single person running cutouts? All I can tell you is sit back, read the posts, see what works and doesn't work for everyone else and then make mods based on that. You should know by now that the headers don't work.

Get those headers and cutouts off your truck--trust me, both are costing you times. I've seen guys at the track with headers run worse than stock (I'm not talking about the long tubes). Put it this way, I was running 13.8's bone stock on F1's on mine, you are barely breaking that on slicks, filter, tranny mod and headers. 86 those headers, get yourself a chip and you will be much happier.

 

i have a chip on the way and trust me i can break these slick loose. It took me a month to learn to NOT to. Last night was a test and im going to keep the cutouts just for ShlTs and giggles and run the high flow cats. And dont force to tell Struk to send you that email I think that Im finnished for a while on modifying my truck. i would like it a little fast but i love the new sound. i like the style and i love the interior. All that i desire is a hard cover and maybe change the grille a little but Im very content. The only reason that i go race is so that i dont drive like a "Maineak" for the rest of the week. like i did before i started racing.

 

and in responce to your "read the posts and see what works and what doesn't" I have yet to see anyone run cutouts before the cats. that's why i call myself the gunni pig. Also i do read the posts. Maybe 20-30 a day

 

Spade$,
That's what I'm saying, yes, you being a reader of the posts, you know that nobody else is running the cutouts. I'm saying that should tell you something.

Oh forget that, knowing you are wanting a tonneau, I'm not gonna take mine off at the track and ask to let it sit on your truck. The minute I'd go to the lanes, you'd be outta there and cruisin home with a new tonneau.

See you next Wednesday.