gtodoug

iTrader: (1)

This is a brief story about my experience switching from American Racing 1 7/8" catless headers to LG Pro catted Lontubes.

Back in late January I called LG motorsports to see if they had any C6 Z06 exhausts laying around. My QTP cutouts had broken 3 times and I wanted a way to have a loud/quiet exhaust. I figured the NPP option would be a good alternative due to it's simplicity and reliability. I already had a Borla Exhaust on the car and hoped I wouldn't lose any hp when comparing the OEM system vs. aftermarket.

Anthony @ LG was the rep who took the phone call and was asking me my motor, compression, and overall setup of my car. I'm thinking.....dude, do you have the exhaust or not? Anyway, after about 30min of talking to me about my setup he asked if I would be intrested in switching headers. Now, I alreay have American Racing 1 7/8" catless headers on the car at this point, why would I want to switch? As far as I'm concerned I have a 403ci stroker motor and I think that I would need the additional airflow that the 1 7/8" header provides right? Well, he made me a great deal and allowed me to trade-in my AR headers and I came out of pocket for the balance.

I asked Anthony what type of power did he think I would gain. His exact words were: " you'll pick up 20-25lfb ft of tq under the curve and gain 10-15peak, you may lose 5hp or so by doing the swap though." I thought for a minute and figured that sounds reasonable. Lose a few peak for more power under the curve. I was extremely skeptical though. Most of the comparisons I've seen are done in house and I know how to trick a dyno just like anyone else. As soon as I got off the phone, buyers remorse set in. Oh well I thought to myself, worst case scenario is that I'll lose a few hp, and have a brand new set of headers.

Well it has been several weeks and I've just now got around to installing the headers and getting on a dyno.

Ok, a couple of facts. I went to the dyno to make a hp pull and get a clean tq reading before the swap. My previous dyno would only occasionally get me an accurate tq reading. Previously my car made a true best of 515ish. That particular dyno sheet has a spike from hitting the revlimiter at the end of the pull. My basline before the swap was 505whp/450wtq. The car has consistently dyno'd just over 500whp so the 505 from the new dyno sat with me well.

Honestly, how much could I expect to gain by putting a smaller header and adding cats to the car? I figured the car would make 490ish and 455tq peak with gains of 10-12wtq under the curve. I figured that to be a more realistic gain than what Anthony quoted me and what I would accept as justifiable swap.

I was able to get on the dyno where Jeremy Formato of FasterProms would help me squeeze some more power. There wasn't much power to be picked up by tuning to be honest. I think 1-2whp peak and 5-6wtq from the first "after install baseline pull". We cleaned up the fuel map and called it a day. I rushed home as I was late for an appointment. When I reached home and I overlayed the graphs.......

HOLY COW!!

I couldn't believe my own eyes. I verified to make sure it was my new graph and my old graph. I'm still in shock! The car pickedup 18wtq peak and 34wtq peak under the curve!!! This is over a 2500rpm range. I got kicked off the dyno before we could work on the 2000-3500rpm range. I did lose 2-3hp over 300rpm in the power peak area but I'm also running cats on the car where previously I was not. We tuned from 3500rpms to redline. The graph speaks for itself. There is still some power left to be had with some fine tuning and street tuning.

This power is for real guys. This is from 2000 miles away, installed here with my own eyes. The previous tune was done by me and the new tune was adjusted by Jeremy Formato. Keep in mind these results are going from catless headers to headers with cats. If I wasn't using cats the gains would be greater.




I want to thank Anthony, Bobby, and Lou over at LG for selling a product that really works! Thanks especially to Anthony who took the time to ask me some questions and not just give me what I want. We all modify our cars in the quest of going faster. Having quality reps like Anthony on your staff Lou teaches guys like me that sometimes to speed up, you need to slow down and really evaluate your setup. I may be calling you guys for cam advice to see what you'd recommend to pick up some more tq. You guys have been great and I really do appreciate it.

Let me know what you guys think!

Dougie

Damian

iTrader: (89)

LG headers are the dookie. No doubt about it. TQ monsters.

ExceSSive

iTrader: (13)

Tell us more about your set up. What heads are you using? What cam? What kind of rear and gears, stock? Great gains from the smaller header...who would have thunk it? Although

transAm-98

iTrader: (1)

So when is LG finally gonna come out with some F-body headers.

Nice gains BTW

xxxhp

long live header wars

gtodoug

iTrader: (1)

LME built 403 w/ callies/weisco internals
AFR 225's
11.3:1CR
SCR 7.8:1
CM 244/250 .645/.645 114lsa cam
Powerbond pulley
Mamo ported fast
stock water pump
all belts
LG pro lt's w/cats
Stock Z06 exhaust
callaway honker induction
ported tb
stock maf
svo 30lb injectors

That is all the goodies. I'm thinking of switching to YT ultralites and a cam swap for some more power under the curve and to bring the SCR up.
Dougie

ExceSSive

iTrader: (13)

Nice set up.

Patrick G

iTrader: (14)

Holy Cow is right. Very impressive.

30th t/a

iTrader: (51)

wow! nice right up and awesome gains. I bet you really feel that on the street.

52172

iTrader: (2)

Lg pro's are the cream of the crop. I think LG has made just over 600 rwhp using them with 427 cubed ls7 even in the 1 3/4 diameter. Shows how well they flow. They are the longest long tube on the planet.

allngn_c5

iTrader: (3)

Awesome post brother. You said exactly what I have been saying for the last 3 years to everyone that PM's me about LG Motorsports. I am well acquainted with Bobby, Anthony, and the rest of the crew. They all want the same thing, to help the customer get exactly what they need, and give it to them for a great price. Who else would've gave you credit for your used headers ?? Gee, I can't think of anyone. At any rate very glad to see you picked up so much usable rwtq under the curve. Please post the new graph after you finish the fine tuning. I'll bet you pick up a bit more. Good luck and thanks for spreading the truth about LG Motorsports Pro Longtube headers. With a company slogan like "we race, you win" would you expect anything less then the best ?

LS1TORQ

iTrader: (1)

Very impressive, goes to show you how important headers are and its funny how many people over look them and get cheapo's. I have seen similar results from a heads and cam 346ci swapping from pacesetters to QTP's.

52172

iTrader: (2)

Yes I think the QTP's are still the best f bod header.

gtodoug

iTrader: (1)

Thanks guys!

mike c.

iTrader: (1)

WOW! Amazing results from a header swap.

drz

iTrader: (3)

That's a pretty good increase in tq, no question, but it look like the engine is down on torque IN GENERAL. 450ft-lb out of a 403, no matter what the headers are, indicates there's a big mismatch of parts somewhere. Most well-sorted 40X inch motors are putting out much closer to (some even over) 500ft-lb at the wheels, with 1-7/8", and even 1-7/8" stepped to 2" headers. There are even some 347s dynoing near 450ft-lb with 1-7/8" headers, so it certainly isn't the American Racing headers keeping this 403 motor soft in the torque department, and the 1-3/4 headers could be just band-aiding a poor cam/head combination.

The gains not withstanding, there's a mismatch somewhere other than the headers that will account for the soft torque before the swap.

allngn_c5

iTrader: (3)

If you take a look at post #6 OP outlines his build. His compression is 11.3, it could be a bit higher which would help with torque. Nothing wrong with his choice of AFR 225 heads. He's got the best on the market. The one thing I would be concerned with is the STOCK MAF. That has to be restricting the hell out of his motor. Just my 2 cents. That cam is pretty big too, 244/250 .645 I like the duration, but not the lift. Again just my 2 cents.

KONG

iTrader: (4)

I agree with DRZ. The cam choice is the majority of the problem. Cams of that size need substantially more compression than what he has to be effective. For everybody that thinks stock mafs are an airflow restriction do your homework and don't believe the hype. I have personally seen a Procharged Firebird push a stock maf to the tune of 690rwhp. It was completely maxed out and then the vehicle was converted to SD. A stock maf on a street N/A set-up would NEVER become a restriction!! The intake manifold is usually the restriction, ported or not.

Impressive gains none the less, but the cam is less than optimal for your current set-up. Good Luck!!

allngn_c5

iTrader: (3)

Thanks for adding what I was thinking but forgot. You are very correct. All that lift with a good amount of duration would require something in the 11.8 or 12 to 1 compression to really optimize the OP's combo. However he's got nothing to sneeze at the way it is now.

7420NW7TH

iTrader: (8)

That pretty incredible