anyone on here running one with a pettit ic? wondering if it effects spool of turbo. post pics if u do!

 

I have a Coolcharge3 on my car and I have no problem spooling.

 

If anything, it should spool faster than some other setups as the pipe runs are short, should be very little pressure drop. On another note, silverTRD what is your porting? I didn't make anywhere near that much power with my 8374 setup on a dynojet dyno.

 

If you aren't making 400+ on an 8374 you are doing something wrong or your boost isn't turned up.

 

355 was the best run. Dynojet uncorrected. Most were under 350. Stockport with 3" exhaust to pettit/racing beat dual tip. Boost was about 14 psi.

 

I’m on a medium to large streetport. That’s what DJ calls it if I remember right. My irons are also ported at the LIM to the larger 13bre runners. I am running water meth so I’m picking up a little there. I believe Ptrhahn made similar power at 15lbs as well, maybe more actually.

 

On pump gas? That actually sounds pretty reasonable at 14psi with stockport and 3" exhaust.

 

Ditching the Racing Beat catback for anything else should get you 15-25hp for starters.

Its not that I have anything against Racing Beat, they are a bad *** company. I believe Banzai Racing has found this and should have the before and after dynos.

If you want a similar quiet and conservative looking exhaust you can get Tanabe Medallion.

 

I don't mean to jack the op's thread, but this is the problem-- https://www.rx7club.com/single-turbo...sults-1118515/
Identical setup, stock port, 8374, 93 pump, AI, restrictive exhaust, same place, same dyno, he's boosting 20+psi, my setup will hardly break 15 and settles to 13.5-14. I have a boost control issue it seems. See my build thread for more info.

 

glad to see other people running same intercooler.
was hoping core wouldn't be too big

 

Even as someone with a SMIC, I will strongly suggest that intercooler core temp at cruise will have a far bigger impact than intake tract volume to response/boost threshold. If you were talking exhaust manifold volume it's a different story.

 

I'm not sure what core Petit uses. If Spearco, like the ASP/M2 intercoolers, a test was done in the late 90's/early 2000's comparing the stock IC to others available at the time and the M2 Large only lost 1 or 2 psi. That test used to be archived on the Lightning in a World of Thunder web site.

The short piping aids response too.

 

Looking at the medalion it looks like a copy of the RB single tip. Are the two really that different? Or is it the RB dual that is more restrictive?​​​​​​

 

For what its worth, I don't think the RB stuff is too restrictive on all applications. I tuned an FC with an RB dual catback, 8374 cast IWG kit, and it made 503rwhp @ 17.5 psi ( medium streetport, and E85).

 

FC RB exhaust has a "y pipe" that splits from 3" into two 2 3/8" pipes and two straight through mufflers- its not the same as RB FD exhaust which has bad "s" bend with flanges right before the single restrictive muffler.

 

But isn't an s bend necessary to get under the subframe regardless of catback?

 

In regards to the Racing Beat mufflers, there were at least two different style of tips and how they branded the tips from the originals to now. Does anyone know if the muffler canister was changed?

I have an original one that bought in 1997 when they still sold them with the option for mild steel construction.

 

I'm on apexi n1 dual with magna flow resonator. hopefully that isnt restrictive

 

That is one of the least restrictive 3” catbacks for the FD. Guaranteed to make every neighbor hate you.

 

For those who say the RB duals don't flow well. 725hp in a 2 rotor is good enough for me...

 

It's well documented that they don't flow as well as others. Not that they don't flow well at all.

I guarantee that swapping to a free flowing exhaust on whatever car made 725 you'd pick up like 50hp. They must have been running a ton of boost on a whopping turbo.

 

Amazing what high priority external wastegate can do isnt it.

If external wastegate can flow enough the cat back doesnt have to.

This is Twins Turbo long runner exhaust manifold with extreme external wastegate priority like on that car.



Exhaust has easier path to the external wastegate than to the turbo itself.

 

The Racing Beat catback has been found to be restriction on the stock twins with internal wastegate (so all exhaust must go through the catback.)

Internal wastegate version of EFR will be the same story.

 

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i run a single outlet RB catback along with a Borla 40944 mid muffler and consider it to be top notch. i did check the RB muffler and verified the I D at 3 inches so i don't see it as restrictive.

perhaps the dual outlet RB might be restrictive however i don't have any experience with it.

as far as WG sizing, it does of course greatly depend on the manifold design. from a power standpoint ideally you want no wastegate to impede flow. of course flow must be controlled. to the extent you bias the manifold in favor of the WG position V flow you can run a smaller WG(s) but you give up in drive to the turbo. it is a balancing act.

my manifold purposely favors flow over WG position. WG outlet flow joins the downpipe at a friendly shallow angle. i use a single large Tial V60 wg and have no boost creep running an EFR9180 at 15 psi. boost range in this log running off the spring was between 15.2 and 15.8.