id like to add some pony's to my rx but im not really sure what is a cheap way to add some .... any help will be welcome....thanx













Johnny

cat eliminator



Probably the best HP per dollar mod that you will actually notice the difference is replacing your cats with a pipe and presilencer or high flow main cat.



There is a whole staged write up on this subject in FAQ's. I can't remember the name of it.

A much cheaper version.Rx7.com

I don't think there is any air tube on that. Is the air pump by itself enough pressure for the 5/6 ports on an S4?

For a easy bolt on use the Bonez high flow converter and pipe, and there will be no 5-6 port problems.

I know people here don't like it, but the reality is a good solid nitrous kit. 50 HP to the wheels for under $400 isn't bad. Do your homework as it's more involved than just spraying it. Properly done it can be VERY rewarding.

it does, I had it, my ports opened.

On an s4...if you replace the cats w/ the bonez pipe you wont need the airpump..its only used to aid the cats on S4s...the S5s use it for 5th &6th port actuation and cat help, lol...take it off if you go bonez, but good luck getting inspected.

u could always just hog out your cat's and put them back....hehehehehe..tobad if some one finds out your busted













Johnny

Ok, so there is a backpressure pipe on the $160 race version? I'm asking for myself now since the pre-cat flanges are starting to leak more and more each week on my 86. I have the RB setup on my 88 and I like it but I'm not spending that much again.

Why in the world people dont use a converter versus straight pipes on a N/A is beyond me.

The performance is the same and it will pass emissions.

Get beyond the idea that just becuase you take off the converter your performance will increase to warrant having a illegal car.



Take into consideration that the converters on your 15 year old plus car are probably shot and replacing it with a single high performance high flow converter built by todays standards versus the highly restrictive deisgn of the 80's will give you the same performance as no converters.



Maaaaaybe your talking less then 5hp versus straight thru.

It was a pleasure and a relief for my car to finally pass emissions on its own and me not have to throw the guy an extra $50 to pass the car. Not to mention how much cleaner the exaust is, at least I can breathe behind the car again!

Its getting harder and harder to beat the system, here they wheel dyno the car for emissions and have cameras watching everything. Its easier and the ecologically correct thing to just comply with the law.

well, yet again rob you are right. in the 80's it was the only way to go, but in the 90's even the rednecks have cats. hopefully the renisis is cheap and available, it should pass smog with no cat, or just the cat



mike

To further emphasize what Rob said, most modern matrix style converters will only add at max 2 psi of back pressure which is far less than 5 hp. more like <2.5hp. You can gain that back by just taking a big ****. If anything get some good headers or drop the engine bay temp. or make a good intake.

In the 80s if you took the converter off, left all the other emissions and had a custom exaust made being as there were no off-the-shelf exausts made, your car really did gain about 30 hp ( this was on a typical V-8 car like a Trans Am, corvette, etc..) its not like that anymore. The converters in the 80s were HORRIBLE! High flow converters were non-existant or so high in price no one used them.

true, and ppl today still believe that v8s gain like 1000hp off exhaust, LOL. So high flow-cats are really good, now-a-days, huh? They are just too spendy, though.

I paid $69 new for mine. Its stainless steel too.

Sounds good to me... If I can get a good stainless main cat for $69 and have a pipe made fine.. but I'm not paying $300+ for the Bonez pipe with cat when the race pipe is $160 just because my 17 year old car has clogged cats. I understand your point about emissions but fortunately for me, there are none in my area. Where did you get an SS cat for $69?

Summit racing, Catco is the brand, you will still need a pipe made though.

pic:

69?! wow, well if I already didn't have a RB exhaust, i would try one of those, but then again I have a haltech so I can tune the idle mixture, so i won't have that nasty smell, I wonder how big of a difference there is between a high flo cat and a straighpipe on a turbo? Maybe I will find out, I plan on going to the dyno a lot.

The Haltech wont help the nature of the rotory with the overlap,

the fumes will worse on a ported motor. One of the reasons the Renesis is cleaner

running is because they took out the periphial ports.

Looks good. I was just at the site and they have a catco universal 2.5" inlet by 16" long for $73 with air tube. Is that the one you got? That is a great deal for stainless.

I was talking about the running rich at idle, thats why it stink when you chop off your cats.

hmm, I wonder, I plan on doing a true dual set up, custom at the shop, maybe I should acquire a couple new cats

you could also take off your 2ndary buttlerfly in the TB, remove the shaft, plug it and port it all at the same time. but

your car better not be daily driven for all of this.



for a street port "instructional" go to

http://www.rx7club.com/forum/showthread.ph...ght=Street+Port

I was talking about the running rich at idle, thats why it stink when you chop off your cats. [/quote]

its still going to stink, lol



FC- thats the converter I got.

I was talking about the running rich at idle, thats why it stink when you chop off your cats. [/quote]

its still going to stink, lol



FC- thats the converter I got. [/quote]

I ordered the 14" version because I'm that cheap... it was only $55. With a pipe fabricated, the whole thing should be around $100-120 and street legal... can't beat that.



Rob, how loud is it compared to stock with the stock cat back exhaust and this converter and a pipe to the stock exhaust manifold? Since this is a universal cat and my original air tube connection is cut (no wonder my 5/6 ports are stuck shut), can they use a hose of some sort or will they have to weld in a new backpressure tube also?



Thanks.

They can weld a new hose, it shouldnt be hard for them, a hose can also be used, not sure how long it will last on there though?



I never heard one with stock exaust so I cant help you there, sorry. It should be interesting to hear how it goes for you though, it will be louder then your old set-up.

You need to keep back pressure on a N/A car to keep hp and tork, so your going to want a high flow cat like everyone is saying..



A simple SAFC would probably be the first thing you should get so you will be able to adjust for the mods as you put them on the car.

Then I'd get a muffler and a header, they are cheap and easy to install.. Once you've got the exaust freed up and flowing smoother then I would go to the intake side and upgrade the air filter and put on a diffrent AFM.. The Apexi SAFC will allow you to get a better airflow meter and make it work on your car by adjusting the input and output setting for the diffrent air flow meter signal. After that pick up a good set of plug wires... Then you may want to upgrade to a slightly better clutch and a light weight flywheel..



Some free stuff you can do is remove the A/C, Air pump and strip the car of all unneccisary weight to lessen hp loss from drag and to up the hp to weight ratio of the car.

My friend put down 163 RWHP out of his 86 GXL. With pretty much all the mods listed above, and some tuning. Also Pullies, E-fan, header wrap, manual rack, but kept the A/C