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-   -   Exhaust question...+ (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/exhaust-question-27430/)

Ryde _Or_Die 10-23-01 12:40 AM

Exhaust question...+
 
If I buy dual out let headers & have some shop weld straight pipes from the headers back to mufflers will this give enough back pressure to open the 5th & 6th ports? Thanks.

Ryde _Or_Die 10-23-01 01:56 AM

come on guys....

classic_italian 10-23-01 02:02 AM

just wire yor ports open:D

Ryde _Or_Die 10-23-01 02:06 AM

You know that doesn't help unless you can't get them to open, right? They need to open when they were meant to, to get the most out of you car. I was just wondering if anyone knew if there was enough back pressure from the mufflers & header to open them. Thanks though.

CYAL8R 10-23-01 08:10 AM

no there won't be, you'll need a nice straight pipe or hi-flow cat to create enough back pressure. im trying to do the same thing right now...those 2 last ports are a bitch to work with when re-doing the exhaust :crzyeye:

Ryde _Or_Die 10-23-01 08:42 AM


Originally posted by CYAL8R
no there won't be, you'll need a nice straight pipe or hi-flow cat to create enough back pressure. im trying to do the same thing right now...those 2 last ports are a bitch to work with when re-doing the exhaust :crzyeye:
A nice straight pipe? If they won't open with straight pipes I will just buy the presilencers that come with Mazdatrix's true-dual exhaust system. Thanks.

mprime 10-23-01 09:23 AM

Look at the diagram at the bottom of my page here http://homepage.mac.com/macimusprime/photo2.html this is how Mind train makes the ports work and it does work very well.

BhamBill 10-23-01 09:21 PM


Originally posted by mprime
Look at the diagram at the bottom of my page here http://homepage.mac.com/macimusprime/photo2.html this is how Mind train makes the ports work and it does work very well.
That's helpful. I picked up a used Mindtrain unit and it didn't have the bleeder screw. Thing really whistles. Is the bleeder screw hollow? Maybe I can get one from Mindtrain.

MaxRX7 10-23-01 09:38 PM

the whole prurpose of installing "straight pipes/cutome exhaust" is to not have to shell out the greenbacks $$$$$$.

If you are going to put 2 pre-silencers $190 each ~$400 :eek: + $150 headers + ~$200 mufflers + ~$100 labor = ~$900

just buy the entire true dual system and don't worry about anything....

Otherwise just go the cheap route and have some pipes made... and wire your 6ports.

Ryde _Or_Die 10-23-01 09:51 PM

Actually going to be headers, $200, presilencers $130 each, so $260, & mufflers, $100 each, so $200. That adds up to $660. Then say $100 for piping and labor. Thats $760. $1400+tax+shipping...prolly around $1500-1600. So say $1500-760=740...if my math is right, lol. Thats almost half off. I definitely think its worth it.

mprime 10-23-01 09:54 PM

1 yes Im sure Mindtrain would get you a bleeder screw just give them a call.

2 UH I realize you want to fab your own exhuast. Thats why I made the diagram incase anyone else needs a good way to figure out the 6 port problem its not like its a hard fab job a flange welded to whatever pipe is close and a bleeder bolt threaded through the flange, that bolts to the backpressure tube. Thats all.

MaxRX7 10-23-01 10:03 PM

since when are the presilencers $130 each ?
they are NOT RB are they ?

Ryde _Or_Die 10-23-01 10:17 PM

Ya, they are RB presilencers. They are the ones for 1st gens, like 81-85 or something. I called mazdatrix today and he says he uses those in his "full true-dual exhaust system". So the presilencers are $130 each. Saves $140. Always a plus.

RX-7 GT 10-23-01 10:22 PM

your spending awfully alot of money just for an exhaust. what is this a drag car:D ? i always go best bang for the buck:cool:

MaxRX7 10-23-01 10:23 PM

:mad: I paid like $180 + shipping :mad:

Ryde _Or_Die 10-23-01 10:25 PM


Originally posted by RX-7 GT
your spending awfully alot of money just for an exhaust. what is this a drag car:D ? i always go best bang for the buck:cool:

Kinda sorta. Its my personal street drag car :D I want it as fast as possible in the 1/4 mile thats all. How is $750 on full exhaust expensive though? I know alot of people spend more than that on just a catback that gives them a grand total of 5rwhp. I plan on getting around 20 or more hopefully.

RX-7 GT 10-23-01 10:30 PM

apexi n1 catback for turboII is 400$ for me. plus gaining over 40+HP...tell me how is that expensive and 5HP:D

MaxRX7 10-23-01 10:31 PM


Originally posted by Ryde _Or_Die



Kinda sorta. Its my personal street drag car :D I want it as fast as possible in the 1/4 mile thats all. How is $750 on full exhaust expensive though? I know alot of people spend more than that on just a catback that gives them a grand total of 5rwhp. I plan on getting around 20 or more hopefully.

yes...

how do honduhs gain rwhp, if they're FWD ? :D

The type R sticker is wellworth the $20 for 5 hp. I know because I bought one for my honduh lawnmower and now it hauls !!!

Ryde _Or_Die 10-23-01 10:33 PM

Man TIIs don't count, lol. Was that for the single or the dual? Still think that $760 is not a bad price at all. Much better then the $1400 I was saving up. Might even get more gains with my setup, never know.

Ryde _Or_Die 10-23-01 10:35 PM


Originally posted by MaxRX7


yes...

how do honduhs gain rwhp, if they're FWD ? :D

The type R sticker is wellworth the $20 for 5 hp. I know because I bought one for my honduh lawnmower and now it hauls !!!


Hey, I never said hondas. You know what I am talkin bout anyways, "whp." Front, rear, or 4 wheel, to the wheels though. Just use to putting "rwhp" cuz I have this weird thing that all sports cars should be rwd. Guess thats just me...

MaxRX7 10-23-01 10:41 PM

suuuure !!


rice boy
rice boy
rice boy
rice boy
rice boy

:)

skibum9199 10-23-01 11:19 PM

I think most people have found that there car is faster in the qtr mile, and has much more low end torque if the 6 ports are closed instead of wired open... I would tend to agree, especially if the car is just your daily driver for school/work/whatever. For your exhaust, get the rb headers, whatver mufflers ya like, and have a muffler shop weld ya up a custom straight pipe. It isn't legal, but hey, what is these days.... :rolleyes:


~Jesse

Ryde _Or_Die 10-24-01 12:55 AM

Ya, I know I am getting the RB headers, just trying to figure out if straight pipes will give enough back pressure to open the 5th & 6th ports. Thats my question really. I almost decided to get the presilencers now just to make sure there will be enough back pressure since no one seems to know really. Thanks.

skibum9199 10-24-01 08:32 PM

Not enough back pressure with just straight pipes.... maybe with the silencers, but I kinda doubt it.

Ryde _Or_Die 10-24-01 08:40 PM


Originally posted by skibum9199
Not enough back pressure with just straight pipes.... maybe with the silencers, but I kinda doubt it.

Well the system that mazdatrix sells uses duak outlet header to dual presilencers & straight pipes to 2 mufflers & they say it opens the 5th & 6th ports. I am planning on the same system basically but half the price.


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