LOnSLO

iTrader: (15)

I have SLP long tubes with Random Tech cats. I had my exhaust guy make up 2 tubes to replace the cats with. Finished putting it all together tonight, and went for a test drive. It honestly feels like I lost 20HP. Can anyone offer anything? I have the o2 sims in, and no codes. Do I need to put the things back on, I hope not <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

Martingale00

Maybe you've reduced too much backpressure and you've lost power down low. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

LOnSLO

iTrader: (15)

I know this doesn't make sense, but it feels like I lost the power at the top end.

NUKEM_SS

I guarantee you backpressure has nothing to do with it. I honestly think it is in your head and unless you are actually feeling the car's power surge down, it is nothing to worry about it. Just to shoot a possibility in the air, the car can be running extremely rich, that might be the cause of it.

roadrunner-r

He might be lean,and loseing timing

LS1 CRAZY

Hey LonSlo,
I know what ya mean. I have no explanation for ya but the same happened to me. When I removed my factory exhaust and went with a flow through set-up I lost all my bottom end torque. I put some inserts back in and it made a major difference. Wish I knew why too???

John98LS1

iTrader: (6)

its your comp! get comp tunning youl feel like you gained your 20 hp plus 20 more!! your comp is trying to compinsate for all this free flowing with the headers and OR pipes. problay running rich.

SLowETz

iTrader: (12)

Same scenario here when I went from cats to ORP's. You lose low end tq. but make it up in HP on the high side. Feels like a loss of HP because HP is a function of Tq., and Tq. is what gets the car moving. Dyno both ways on the same car/dyno/day and I bet you see a lower RWTQ w/the ORP's. JMHO........

Slowhawk

iTrader: (12)

On FLP's I lost 15hp/20tq across the rev range WITH the Cats installed.Car was 380hp/375tq,went down to 365hp/355tq.

CrazyBosnian

iTrader: (1)

U just a big dummy, lol <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> j/k... Ur dyno #s just proved to you tonite that you didnt, oh and i think its that ur car was quiet, and got fast as u got on it while it was still quiet, now its louder, and as you get on it the engine is louder but u move the same speed but u are used to be going faster at that loudness of the engine, do u get me, lol, does this make sence, i think its in ur head... <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Oh, and i'm getting that damn cam in a month(maybe some heads too), u better watch out!!! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Kobwo

Backpressure seems to be BAD<<<check it out.

SmaknaSS

iTrader: (1)

I too felt like I lost power when I installed FLP headers W/ORP's on my 01 SS. Even after dialing it in with a MAFT using EFI LIVE V5, Before installing headers I't seems my clutch would slip allot easyer (I could smell the clutch) and my back tires would break away easyer also. I did notice that when my tires do not hook up now after installing headers they seem to spin more now, probably due to gaining hp more towards the top end.