Finished single swap and have dyno resolts
 

okwell my setup is runing a single t66 ona tubular manifold. 550 primary 1680 sec. Apexi power fc with datalogic and commander. 3 inch down pipe to stock cat with a cat back exhaust. large top mount intercooler. and on 91 pump gas for use in CA.runing stock ports.

i put down 250 HP and around 200 torq on 12psi.
i was told that if i get rid of my cat it will increase significantly. also i told the tuner to just be milled on this tune just for reliability leaving enuf timing to be played with later as well.

as far as taking the cat out how much wold that really help i wold just take the entire section out and replace it with a 3in pipe?

Those numbers are pretty low. Post up the dyno sheet and what dyno it was done on.

Replacing the cat can be done with a midpipe or resonated midpipe to keep the DB's down. It will help significantly.

There is a section devoted to dyno numbers and questions.

That does seem very low, with the stock twins you can get close to that with a couple bolt ons.

That tune must be the most conservative tune in the history of mankind. I made 100whp more with stock twins. :scratch:

the cat is also clogged like a mo fo bc i blew up two sets of twins on it and was blowing oil threw everything i was told by the guy hew did the tune that if i take the cat out im lookin at at least 50 to 60 more if not more. also i will post graphs up as soon as they hit my email

Try English. This is not IM.

And does this tuner have a lot of experience tuning rotaries?

Go to a shop and spend $100 to put in a straight mid-pipe if it is that bad.

Those numbers are really low. Do you have a wideband to check the air fuel ratios? Alsowhat other mods do you have? I am at 310whp with the stock twins at 10psi... if the cat is that clogged be careful when you put the straight pipe in. turn up the boost gradually checking the AFRs as you go or you might pop the motor depending on the tune. I would also suggest as others have to find a tuner with rotary experience and have them check it out.

your are going to blow this set up to if you dont chage the clogged cat. Why wouldnt you have done that first??

...and the cure for this was a single turbo conversion?

I never understand why people feel 'upgrading' should always talk precedent over getting everything 'working'.

If you were blowing oil through everything with stock twins, you'll probably continue to blow oil through everything with a single.

Sorry to derail but, mods?

I would remove the cat, and try to shake out all of the loose debris. You may be very surprised at how much crap will come out of there. Once all the crap comes out, it should flow much better.

It will take a good effort to get the cat cleaned out (experience talking). It may clog again at some point, but this should last for a while.

Putting on a mid pipe will give you nasty stinky exhaust, and make you car really loud. Your neighbors will hate you.

I am putting down around 300 rwhp, with a slightly modified oem cat.

I'm with Super here, I would live to know your mods....

To the OP... Replace that cat, get a other tune... Then you will have much higher numbers, probably 100-120 more then current....

J.

performance wise
KD rotary Streetport
PFC
all emissions deleted
Giant no no name intercooler
gredy elbow w/ blow off
non sequential
custom exhaust w/ heat wrapped everything
fast acting AIT
1300cc secondaries
electronic boost controller

I have many more relaibility / suspension mods I like to upgrade reliablity items first before "fun" items. Hence why I am still at 10psi I could easily run more with my setup but I am pretty conservative.

I agree it is funny to go single after blowing an engine. I am basically setting my car up for single with the single turbo being the last item to change over not the first! Need to have all of the supporting mods first or you are just asking to buy another motor.

ive got all the supporting mods for single just the cat is killing me sorry i haven't undated this for awile ive been fixing a fuel leak that developed on a stock fuel fitting. and my plan is to go throw a straight 3in pipe were the cat section is or a large resonating chamber to help with the DB lvl. after geting that put on its going back for a retune.

I just got tuned and mine made 330 at 10psi. something is terribly wrong with your set up.

so you dyno'd it with a clogged cat. Of course the numbers were low.

This was a fun read. What's next on this journey?

Who ended up tuning your car? I know you were looking for a tuner not too long ago.

OP - Those numbers are really REALLY low!

ok, i think he gets that the numbers are low...

Sorry, wrong post

ok so car is at the shop getting an 18in long 4in diameter glass pack in place of the cat 3in inlet and 3 out all piping is 3 in. then im taking it back in for a tune. i just took it to a place here in stockton CA. he said the prob was the cat and that he wold int charge me much for a re tune after the cat gets taken off.

Ray@PFsupercars in MD

ok got the resonating chamber in and sounds good and runs amazing now shes not runing lean or anything im still going to take it in for a re tune. only thing is now it dusint like to start on the first try i can turn the key over and t just keeps going and going and going i let of for a sec turn it agin and starts right up with no hesitation.

why would you run and waste your time tuning as well as dynoing the car if you know the cat is so clogged that you blew out some stock turbos from the back pressure?

the fuel probably primed finally by the time you tried to start it the second time.

Glasspacks and rotaries have been known not to get along...

what hapends with glass packs and rotaries?

Take your pick...

https://www.rx7club.com/showthread.p...ght=Glass+pack

https://www.rx7club.com/showthread.p...ght=Glass+pack

https://www.rx7club.com/showthread.p...ght=Glass+pack

A little research goes a long way, the ideal time to ask questions is typically when you are considering what parts or modifications to add, NOT after you've already done it and you are struggling to figure out why it doesn't work. 2¢

glasspacks in general are not very good mufflers. yes they are cheap, but they are outdated and usually used on old hotrod or muscle car cruisers that arent interested in performance, just sound.

the fact that your exhaust guy put a glasspack on your turbo car shows he wasnt thinking.

a proper straight through perforated core muffler like a magnaflow or borla wrap the perforated core with stainless steel mesh, and then sound absorbing fiber around that, so the fiber cannot be burnt or sucked through the perforations like a glasspack will.

example of magnaflow:
http://image.minitruckinweb.com/f/93...ow_muffler.jpg


now heres what the glasspack looks like inside.
two problems, 1. they usually use louvers instead of perforations, so they hurt air flow more (especially bad for turbo exhaust). 2. there is nothing protecting the sound absorbing material, so it melts and blows out.
that is why they cost 1/3 to 1/4 the price of a good muffler.
http://northgatemuffler.com/images/c...cutaway_lg.jpg


i have a magnaflow 3" oval muffler (i think the same one i linked above) in my midpipe (no cats), and it quited down my car A LOT while giving it a slightly better tone. i would definitely recommend it.

i also have a borla xr1 muffler similar to the one i linked above, it was leftover from a prior project and i havent used it yet, but i can say the construction quality is very good, and wouldnt hestitate to use it instead of the magnaflow.

I have good luck with borla mufflers also