Question for those with aftermarket exhaust.

If i buy an exhaust setup with both cats and test pipes can they easily be swapped out without removing the entire exhaust system each change?

…. simply disconnect Vband from Xpipe and unbolt from turbo studs to swap the two. Assume all you really have to deal with is the heat shield around the turbo and if enough space to clear the exhaust studs with the xpipe still there.

 

yes.

 

Back when my car was still a stock, daily driver- my OEM fuel pump failed with no signs before hand, no sputtering or running rough or anything like that leading up to it. Parked in the garage at work one morning and came out to cranks but doesn't start.

 

thanks, i think ill replace it just in case to be safe.

Does anyone use exhaust studs on these cars, like the ones pictured below? Any reason not too?



Also ...
I am running extended H&R studs on my hubs but whenever i go to take my wheel off I notice they kinda hang a bit and get caught on the threads and i dont want to damage them (the threads) or the wheels.. Would putting some sort of plastic/rubber inserts in the wheel hub be feasible? It's just annoying!

 

Try not to bang the wheels against then, but the wheels are aluminum and the studs are steel, not likely to do any real damage.

 

What wheels do you have and are they with correct hub bore? If the bore is correct on the wheels then the wheel shouldnt hang on the studs when you lift the wheel on the hub and keep it there so it doesnt fall off to hang on the studs.

I'd save my money with upgrading to another stock fuel pump. I would get an aftermarket Walbro with a Radium adapter, but that's just me.

 

stock turbo twists

In all honesty after thinking about it, while i had them off the other day to do my coils/plugs i noticed a bit of water corrosion on the hub and on the inside of the wheel so i will try getting rid of that.

 

If I get tuned with cats installed and take them off after..or vice versa..how much HP am i potentially leaving on the table?

 

Depends on the cats. You could be leaving a lot on the table, or nothing at all. I did a write up on this years ago. Here it is but the pics are gone by now.

https://rennlist.com/forums/996-turb...e-settled.html

 

Speaking of cats, I prefer them on my cars because I hate the smell of catless exhaust and I like to hug trees as much as is reasonable. However, I've been considering re-doing my exhaust (again...) and putting a boost-activated valve prior to the cats to open up some flow under high-power conditions. I don't have my cats deleted from my tune so I'm curious if this will cause me to throw a code? I'm thinking it won't since some exhaust will still be flowing through the cats and second O2 sensor?

 

I'd weld some external gates on and dump tubes before I'd put a bypass there. That's like right behind the exhaust turbine, not ideal placement. Cats have come a long way like John tested prior. Good 100/200 cell aren't losing anything, but the smell.

 

My other train of thought has been to not worry about it because I have what seem to be high quality 100 cell cats (Speedtech) so it might not be worth the effort for little or no gains.

 

I wouldn't bother with pre-cat cutouts, primary O2 sensor readings can get weird when the exhaust dumps to free air near them. If you want to change stuff up, switch to the big HJS Motorsport cats that pwdrhound used to have. They're expensive, but cheaper than redoing a whole exhaust.

 

Mmmmmm, I love the smell of unburnt fuel in the morning...

 

Good read, wish those kind of cats were in my budget..they sound awesome.

I suppose this would be more of a tuner specific question but if I were to get tuned with 200 cell cats and install a set of test pipes afterward, would it throw off the tune?

I know on my MK3 supra, a downpipe will cause boost spike on a cold evening but that car has no boost control other than the wastegate spring.