with open cutout it kinda feels like i don't have as much power as i have with closed?
am i loosing my toruqe or better to say back preassure ?

<img src="images/icons/confused.gif" border="0">

 

I noticed the same thing when I did my headers with the 3" y pipe, it pulls stronger in the higher rpms when I really sink my foot into the pedal, but under 3200 rpms, it is less torquey and responsive than it was with the stock manifolds and exhaust. I imagine with the cutout you are gaining in the higher rpms and losing a little low end response and torque. Some people will disagree because of the results of dyno #'s but SOTP definetly feels more sluggish on the low end.

[ February 23, 2002: Message edited by: brendon ]</p>

 

The "ONLY" way you would lose torque in this scenario is if the change in exhaust setup caused the A/F ratio to be incorrect. The notion of needing some backpressure is nonsense unless that backpressure was keeping your A/F ratio in check.

Tim

 

Air/fuel being equal,I lost almost 4rwhp/4rwtq
with my borla open.My car likes back pressure.

 

yeah guys, it's something about A/F, someone already told me i need to get more air to my engine in order to compensate open cut-out, but i already got fast toys ram air, so i guess i should try to change my stock maf and try grantali maf, otherwise i don't see any other way to get more air to the engine <img src="gr_sad.gif" border="0">
well, my car is stock, 2001 TA(2k miles on it), so my computer is still learning, could happened my A/F became incorrect after i opened my cutout, and my exhaust system is so stock.

 

Just a few thoughts:
I have a ZED cutout and don't notice any loss of low end when I open it.
I once put headers and glass packs on a '69 Chevy small block and lost low end torque.
My muffler guy took the cats off his Grand National and then put them back on because he lost the low end.
Over the years, I've had a few y-pipes rust out, on varouus cars, and when I replaced them throttle response seemed better.

 

Regardless of air/fuel or whatever the reason is for losing low end you will lose TQ or shift your power band higher if you open your exhaust too much. It's been proven during tests with different exhaust systems some create more TQ while other lost some TQ but gained more top end HP.

 

Don't waste money on the Granatelli, get a Pace 85mm calibrated screenless MAF, and maybe a Katech throttle body. Both VERY nice pieces, and I have witnessed nice gains with both. I am half way there with the MAF!
Jay