MurderafterMidnight

Thanks in advance.

williamGT

iTrader: (5)

Maybe 20HP, I know k&n website says 13.88HP and magnaflow is 7HP.

06 SS

Since neither the exhaust aft of the cat-con or the air filter assembly are the biggest restriction, I would bet you get less than 5 horsepower total. Better off spending the cash on a dyno tune and getting rid of some of the torque management.

Mels SS

iTrader: (1)

Our exhaust system is very restrictive and the the air in take is like a hangman's noose
on these motors.

JDMC5

iTrader: (3)

15 at the wheels is a conservative number.

DavidGXP

iTrader: (14)

Keep in mind you'll need tuning after doing those two mods. So... with tuning you should put down about 265-270fwhp. depending on the dyno.

https://ls1tech.com/forums/ls4-front...y-11-17-a.html

06 SS

The bottleneck is at the intake manifold, opening up the air intake will not improve that much at all as it piles up at the intake manifold entry point on the LS4. My personal belief is that the oiled filters are a detriment to performance as well, but I am not going to argue with a fancy ad campaign featuring claims that I have never seen anyone duplicate in the real world.

The exhaust is bottlenecked at the downpipe (again, in my opinion), opening up the exhaust after the cat (after the gasses have cooled and take up less space) will not gain much.

Downpipe should net you more gain that any cat-back (bigger pipe when the exhaust gasses are at their hottest). Getting cooler air into the inlet will gain you more than any fancy air intake or filter change (both the K&N and the stock bits pull their air from the same place.)

Exhaust changes via cat-back systems are good for sound changes only. The same could be said of a K&N-type system, you will hear the air flow due to the open element, it may sound faster, but I doubt it will be in any measurable way unless it temporarily fools the computer into leaning up the mixture until it relearns how to react to the MAF readings. Then right back to normal.

CenTexSS

iTrader: (2)

I'd get a DP before the cat-back. Intake, DP, and a tune would net you great gains.

AlabamaGuy

iTrader: (5)

Well the intake might free up 5hp then the Flowmaster will take 3hp away....so you'll come out the same without a tune to back it up.

Buy a Catless DP and a cutout.

DavidGXP

iTrader: (14)

Also, the rear manifold outlet is only 2 1/2" id so a 3" downpipe won't really add much more power either.
And 06 SS, is right. The restriction is in the intake manifold and then the exhaust manifolds. Headers only add about 6-10 hp. Maybe, a little more with tuning. I really don't think that they are worth the money tell we can start sucking more air.
The best bang per buck, is LS6 yellow valve springs with 1.8 roller rockers.
With exhaust, CAI, rockers, springs, tuning and 6100 rpm shift points you should be mid to low 13's@105mph. (2.0 or better 60ft) NOTE: I said 6100rpm shift points with springs and rockers this is important!

AlabamaGuy

iTrader: (5)

3" Catless DP, cutout, and a tune put me at a 13.7 in the 1/4 with a 2.0 60'. Adding headers and full 3" exhaust with a GOOD muffler put me to 13.4 with a 2.2 60'. Considering I could get the 60' back down to a 2.0...we're looking at a 13 flat car considering that every tenth in the 60' is worth 2/10ths in the 1/4.

That's worth the money to me.

DavidGXP

iTrader: (14)

Yep with just a down pipe and u bend delete I went from 238fwhp to 255fwp after tuning. I think I would have put down 255 before the DP and delete though, cause those two mods threw the A/F mixture way off.

DavidGXP

iTrader: (14)

Yeah... you gained torque and hardly any hp. I believe your mph only went up .5?

AlabamaGuy

iTrader: (5)

I lost torque and gained HP on a dyno that had been recalibrated. I can't compare my before and after runs but I can compare my time slips. And a consistent loss of 0.3 seconds with a consistent gain of 0.2 seconds in the 60' show how much stronger the car really is after headers and a tune. Who WOULDN'T pay $650 for that kind of gain?

DavidGXP

iTrader: (14)

I need to get my *** to the track and see for myself. I was just discouraged from reading your dyno posts and seeing your track times/mph. I didn't know you only got 2.2 60ft times. you just, said spinning.. so now I know. Your avg. gain with tuning is incredible though..
I need a re tune. I'm just trying to get everything done at once (LS6 intake install) I'm about to just say F it though, and get it dyno tuned anyway.

AlabamaGuy

iTrader: (5)

I went from cutting one of the best short times on here, before headers, to cutting a 2.2. Headers and a tune picked up so much under the curve, when my converter locks up I'm at 245 lb-ft...right there off the line. Hell on the street if I just hold the wheel straight, it'll change lanes rolling into 3/4 throttle.

DavidGXP

iTrader: (14)

AlabamaGuy

iTrader: (5)

LOL, shut up. Your car's going to be MUCH stronger once you finish the LS6 swap. Hell, it will be anyway with the rockers, that's like 18hp right there. Hurry up and get done so you can be the Macdaddy of the LS4 section.

CenTexSS

iTrader: (2)

.3 seconds quicker with a 2.2 60 foot - that's good enough for me! Before and after dyno numbers aren't relavent - real world numbers from the track is what I'd be looking for, rather than being caught up on dyno numbers.

DavidGXP

iTrader: (14)

It's about 70* outside, and I'm tempted to try to throw it on and get tuned next Friday. Then... a few questions started to rome through my head...Will the tb and maf work for now.. or will I need instant tuning? Still need my freeze plug and LPE map relocation kit. Dam.... it!

I've got a guy that I work with and he's determined to have the FASTEST FORD everything. All of his cars look like **** but run pretty good. Right now were pretty much head to head, when it comes to his super poop. I mean coupe (don't tell him or let him see that OK? LOL) We went out to the 1/4 last year and I was stuck at 14.2's all day with 2.2-2.4 60ft times. This with bald tires and after I installed my DP and U bend delete and before tuning, so my car was all jacked up! My buddy was in the 14.5's at around 94mph compared to my 99.8mph He just got done installing a jack shaft pulley and water meth last week and said he ran a 8.0 in the 1/8th mile. Then, he said the track isn't a true 1/8th mile but its close. He sent some some vids of his car whooping on SS Camaros and says that his MUSTANG and Coupe beats the **** out of LS motors.. Again the fastest everything. He's got a story every day about a new kill and if I raced as much as he does on the street then I'd be in jail. This is the guy that I have to beat so this is my reasoning behind trying to have a bad *** LS4. I think that these cars have so much potential I just get pissed off at how hard and much money it takes to tap into it. I don't mind being FWD, and it's cool to be different. My old Camaro 79 Z/28 406sb ran 12.7's at 108 so I'm trying to match that. I'm thinking that I'm close with the intake swap we'll see......