Scantraxx

Hey guys,

This is the first major mod that I can finally afford to do to my Fbody headers and I have some questions.

These are the headers that I purchased, http://www.summitracing.com/parts/PSM-72C2256

My question with these are that I was told that for the exhaust, Im getting some conflicting information, I want to run true duals 3in exhaust. But I have been told that 2.5in would be the best option. Is the power difference between the two going to be huge or no? Also will there be any sound difference between the two?

I also have one other question. When I bought the car, the previous owners did a couple mods, Air lid, BBK alum intake and matching throttle body. I discovered that my throttle body was only opening about 60%, I work at a CNC shop and my mill programmer made me a matching throttlebody space to bring the body out more to make it open up correctly. After I got it all together, I started getting check engine lights, I have a hyperpac tuner and getting system lean codes getting thrown. The issue is from the rubber coupling connecting the MAF to the throttle body. Does anyone know where I can buy one or something better? Thanks.

pic of the coupling

Blackpanther99

iTrader: (8)

Go 3" all the way. If you do cam and heads upgrade you will need it.

demonspeed

iTrader: (7)

3" duals were the default option for many, many years. To honest, I've not kept up with when/how/why the "experts" decided that 2.5" is what everyone should have.* You'll be fine with 3" -- and it'll give you plenty of room to grow.

My quick fix for the MAF/throttle body issue you've got? Sell the BBK stuff and pick up a LS6 intake (throw on the '04 LS6 PCV conversion while you're at it), ported stock TB, and factory bellows.


*I find it even more hypocritical [amusing?] when the same people professing how one should go with 2.5" duals are then just as quick to tell people that they should not go smaller than 1-7/8" primaries for their headers.

Scantraxx

Thanks guys for the response. I wrote that half asleep, I did intend to say that I'm looking to eventually make it a 500hp car, heads and cam being next years add on. I'll just stick with the 3" exhaust setup then.

Also why switch to the ls6 intake and throttle body?

Fourth-Gen Man

I have the BBK intake. No problems here at all. I remember reading in a thread with back to back dynos that the BBK provided five more hp than the LS6 intake on that person's Camaro. Switching to an LS6 intake is just plain silly and a complete waste of money in your case IMO. People will claim bullcrap about "heatsoak". This meaning the intake will get hot and cause the air to get hot, therefore a loss in power. However, dyno pulls are done when the engine is already warmed up so heatsoak claims are really just a hypothesis that has no evidence to support it as far as my understanding goes. This will always be debated though (flame-suit on). Only downside to the BBK is it's about ten pounds heavier than the LS6. Still I have not seen a single dyno comparison showing the LS6 to make an equal amount of power or greater to the BBK. I don't think you can go wrong with either of them.

So to address your problem: there were no problems before you started messing with the throttle body?

demonspeed

iTrader: (7)

I only mention getting rid of the BBK setup because you could sell it to someone else and likely break even by going back to a setup which will likely cure the issue you're having. Otherwise, I agree with Fourth-Gen Man: I wouldn't swap a BBK for LS6 just for the sake of swapping. In your case, it *might* "fix" your issue (or you may not even need to go that far -- I just like to suggesting extra work for you )

JRENIGAR

iTrader: (37)

The coupling thats on there is a Fernco PVC type coupling commonly bought at any hardware store for around $5 or so. It was and still is the poor mans alternative to SLP's "smooth Bellows" type coupling that is now about $40 if memory serves me correctly. Either one will work but the Fernco needs to be about 4-5" in lenth and trimmed to fit for a better seal. Yours looks too short to start with and never did fit correctly. This is likely the vaccum leak you have that would be giving a lean code.

Scantraxx

No, at first I figured that the spacer that was made for me, I only put one gasket on rookie move on my part. So I had to tear it all apart then put both gaskets on both sides of the spacer thinking that was it. I have it narrowed down to the rubber coupling. I read on a sticky on here refering to a similar rubber piece sold at home depot and I asked around at my shop, there is an industrial hose shop around town that I figured I can get something made up for it if it comes down to it.

Fourth-Gen Man

I'd bet a beer that it's the rubber coupling. Like JRENIGAR said, it looks way too short. It looks like your lid isn't fully connected to the lip of your MAF sensor because of this.

You can also check your EGR for a leak. I remember after I swapped my intake my EGR grommet was all warped and did not seal 100% so I had to get a new grommet for that. But since there was no problem before you probably don't have a problem at the EGR port. Just a side thought after seeing you still have yours on there.