Just swapped out my Bonez hi-flow cat with Ray's RSS MP. The fit was perfect. The flanges are thick and are wider than than normal. My engine is ported and non-seq which makes it louder than a seq setup. With the RSS DP the exhaust is not noticeably louder at idle or cruising, but a little louder under acceleration. My setup is now: Mind Train DP, Shane Racing RSS MP, and HKS turbo cat-back. The power increase is noticeable. Ray
states about +24 hp increase on a stock engine.

When I had: Mind Train DP, Bonez hi-flow cat, and PFS SS cat-back; it was extremely louder than my new setup.

 

Chuck, How do you like the non-sequential set up..??????

 

Chuck,

The gentleman who posted this thread:

https://www.rx7club.com/vforums/show...threadid=19650

and the dyno charts on Wael's site all seem to show a significant decrease in low end power, and then a sharp increase above 6K. I think this would be even more prevalent in a non-sequential setup. I know you won't have any hard evidence untill you get a dyno run, but can you let us know how you feel it has affected your powerband? TIA.

 

How much was the resonated MP and where did you get it from? Right now I'm trying to decide between a resonated MP or an XR1. I don't want my car any louder then it currently is, but the pettit Resonated MP is $349 while the xr1 is only 100 something.

 

When you get on a dyno I'd be interested in seeing the results as well.

Interesting that the resonated mid would be quieter than the high flo....always heard the opposite

 

The RSSMP is from Ray at Shane Racing and with shipping came to $346. It is not quieter than the Bonez hi-flow cat, but is only very slightly louder under full throttle. Kyle Krutilek has a home made resonated MP on his big single turbo large port engine and it is also very quiet considering his mods. As I previous said, when I had a PFS SS cat-back with the hi-flow cat, it was extremely loud and that was due to the cat-back. The HKS cat-back is a lot quieter than the PFS. The RSSMP with HKS is nice sounding and not loud.

I have been running non-seq for two years. It is true that low end power is less than seq, but driveablity in mine is not lost. I have not noticed any power loss at lower revs when switching from the hi-flow cat to MD, and this is my second time doing it. That info about losing
noticeable low end and the benefit only being above 6K rpms might be true with some engines depending on their setup. It is not true in my case. Their are many factors that govern how well a system works. Mine works better all around with the MP over the cat. Kyle was amazed by my setup and went single turbo after driving my car.
But I am a fanatic and modified the complete intake and exhaust to work together better.

A group of us is buying our own uego AFR monitor system to tune our cars with. This is necessary because most dyno shops in Houston do not even have O2 sensors to monitor the AFR, and the ones that do reserve their good units only for themselves. I paid $75 extra at one shop to use their Bosch linear 5 wire O2 sensor, and it was crap. I lost HP tuning by it and went back to my orig PFC setting after my three runs. I plan to dyno soon.

Since I also just installed a Blitz FMIC, I need to make a new cold air system since the M2 one will not work any more. Also have to figure where to move the Crane HI-6R to.

 

That's one of the reasons I'm probably going to go with the RX-7 Fashion FMIC eventually. I love my M2 Intake and can't bare to part with it.

Thanks for the info, I'd love to see the dyno graphs once you get them done.

 

I'm one of the few people that have benefited from switching from a mp to a hi-flo. With my Apexi N1 my turbos (non-seq)weren't spooling very quickly as I had no back-pressure. Even though on paper I might have lost some high end hp, I gained alot on the low and midrange. But like earlier stated, I am probably one of a few people that have benefited from this.

 

So what are you going to do with your hi flow cat? Do you want to sell it? Let me know.

Thanks
dave

 

Dave,

I am keeping the hi-flow cat because my county is suppose to start emissions testing of some sort next year.

 

Thanks for letting me know. I guess I'll have to look around some more for a used hi flow

thanks