Best HorsePower Gains and Best Sounding Exhaust???


WHaaaaaa
10-30-2003, 09:56 AM
I was trying to find the Best Exhaust for a decent price??? I was thinking about the Apexi GT-Spec but i dunno give me some opinions and some sound clips

kjtar
11-10-2003, 03:27 AM
I was trying to find the Best Exhaust for a decent price??? I was thinking about the Apexi GT-Spec but i dunno give me some opinions and some sound clips

Yeah, I just test drove a '89 GTU and it was too quiet. I'm the kind of guy who likes to listen to the engine and exhaust when I drive, the radio is when I'm on the Interstate. So, any recommendations out there for a good loud (but solid sounding) exhaust system for a '89 GTU?

Thanks,
Tom :banghead:

banditkiller
11-10-2003, 03:03 PM
Remove the cats and get a header from racing beat..... get some custom bent pipe into 2 canister type mufflers...... It will sound pretty nice after that... And with the removal of the cats. and the restrictive stock manifold... you will feel a signifigant power gain. Hope this helps.Ohh.... And the hell with paying 650$ for something I can have done just as well and sounds just as nice for under 250$. just my :2cents:

Jims5543
11-10-2003, 05:37 PM
Definatly go Racing Beat for the Header and Presilancer. (Happy Dana?) As far as cat-back thats up to you. I have no clue what to recomend for a N/A aplication. There are so many out there.

I have seen the Racing Beat and Pacesetter headers side by side and the RB is by far a better header. The bends are less severe and the build quality is much betterer. Racing Beat used to send a block off plate for your ACV. I dont know if they still do that or if you have to buy it. Dont forget a gasket from the engine to the header.

Jims5543
11-10-2003, 05:40 PM
What Year RX-7 are we talking about as well. Is it a 86-88 or a 89-92?? With the 86-88 your 6 ports are activated by exhaust backpressure so you dont want too free of a flowing exhaust. If its 89-92 the 6 ports are controlled by the air pump. If you have a 89-92 make sure you leave your air pump connected.

MyGTR34
11-10-2003, 06:13 PM
Exhaust wise, id go with the Blitz nurspec all the way. It sounds really good. Very deep and gutteral, and loud, and you car definately here the turbos when they kick in. Along with a Greddy blow off valve, it sounds quite nice. Horsepower wise, it helps A LOT.

dayna240sx
11-10-2003, 07:41 PM
Exhaust wise, id go with the Blitz nurspec all the way. It sounds really good. Very deep and gutteral, and loud, and you car definately here the turbos when they kick in. Along with a Greddy blow off valve, it sounds quite nice. Horsepower wise, it helps A LOT.


I wouldnt go with that exhaust. It is way too ricey. You can here the turbos when they kick in? Big deal, I hear my turbo spool at idle. :evillol:

kjtar
11-10-2003, 08:03 PM
Exhaust wise, id go with the Blitz nurspec all the way. It sounds really good. Very deep and gutteral, and loud, and you car definately here the turbos when they kick in. Along with a Greddy blow off valve, it sounds quite nice. Horsepower wise, it helps A LOT.
There were some questions about the year and type of car, so;
1989 RX7 GTU normally aspirated. I live in a non-compliance area, but don't really want to take the cats off. So, with those parameters, what would you guys recommend? Data point, I had a '94 Miata R version, took off the stock exhaust and added a Borla cat back and was very pleased with that sound, but I know that here we're talking rotary versus internal combustion "regular" type engine. "I'm listening." Also, if given your choice of cars to buy and use as a "special" or "weekend" car, would you get (for around $8k) a 1989 Porsche 944S2 or the 1989 Mazda RX7? Both cars have a little over 100k miles on them.

Thanks, everyone.
Tom :rolleyes:

Entreri33
11-11-2003, 03:48 PM
I always liked the dual N1's :evillol: with a offroad pipe or the bonez cat

MyGTR34
11-11-2003, 09:45 PM
heh, sorry, i just thought the exhaust was pretty cool. but i guess being the one i hear the most, it kinda gre on me. But as for N/A, the best sounding has been the dual Apexi N1 exhaust system. The units we have sold to our customers have been great products, seen the most power, and best feedback as to noise, simply cuz they come with silencers, so if ya like it loud, throw em away, but if not, you can jus slide em right in.

J-Rat
11-12-2003, 09:23 PM
If you like a quieter tone, then go Racing Beat. If you want to shake the windows, go N-1.

Jarrett

MazdaB1300
11-19-2003, 08:23 AM
What Year RX-7 are we talking about as well. Is it a 86-88 or a 89-92?? With the 86-88 your 6 ports are activated by exhaust backpressure so you dont want too free of a flowing exhaust. If its 89-92 the 6 ports are controlled by the air pump. If you have a 89-92 make sure you leave your air pump connected.


There are plenty of other ways to run your 6 ports so don't let those keep you from getting a free flowing exhaust. Personally, i run electronically activated six ports.

Jims5543
11-19-2003, 08:40 AM
I am by no means a N/A expert. I have never heard of actuating the 6 ports electronically. How does that work and is it expensive to set up??

J-Rat
11-19-2003, 02:21 PM
There are several ways to actuate 6-ports electronically. And its very cheap. All you need is a pressure source (air pump, etc), a solenoid, and a signal thats rpm activated.

Of course this is for S4 cars only.

Jarrett

kjtar
11-19-2003, 02:23 PM
Can someone please explain to a newbie what the designations S4 and S5 signify? Series? What years are we talking about for what abbreviations?
FAQ material?
Thanks,
Tom

MazdaB1300
11-19-2003, 04:50 PM
I am by no means a N/A expert. I have never heard of actuating the 6 ports electronically. How does that work and is it expensive to set up??


Well....you could do it a few ways electronically. One way is explained at http://www.fc3s.org/how_tos/electrical/6_ports.html . That is not a bad idea and was what i was planning on doing but i didnt' want the noise of an air compressor kicking on, plus i think that would draw a lot more un needed amperage i'm already running underdrive pulleys so i don't need to make my alternator work any harder. What i did was take the guts out of the actuators, so that they didn't have the diaphragm in them anymore and i installed an electric servo from a hobby store in each actuator. Then i ran those to a relay that is activated from an RPM switch which you can get from Summit and then run that switch off of the black wire stickin out of one of your coils, i can't remember which. I don't have definite directions for it, cause i've never heard of anyone doing it the way i have.

BlackLabel6542
11-22-2003, 01:10 PM
Alright i just completely finished my exhaust and i love it! this is what i have:
Road Race Header - RacingBeat.com - $170
2 Presilencers - RacingBeat.com - 2 @ $140 each = $280
2 Non-Turbo Mufflers - RacingBeat.com - 2 @ $220 each = $440
gasket for header - RacingBeat.com - $15
piping to put it all together w/ flanges - local muffler shop - $120

total cost = $1,025

final summation... Sounds Great!
Also has a really big improvement in power but that could also be partly due to me pinning open the 5th and 6th ports permanently
I did that at the same time because now they were no longer actuated off of the backpreasure in the exhaust

MazdaB1300
11-23-2003, 11:56 PM
Also has a really big improvement in power but that could also be partly due to me pinning open the 5th and 6th ports permanently
I did that at the same time because now they were no longer actuated off of the backpreasure in the exhaust


At the local dyno, someone had a 89 N/A rx7 and tried both keeping the six ports open constantly and letting them open on their own, and i can't remember the exact numbers, but they lost quite a bit of torque when they left them open, at least in low RPM range. Up high it didn't make a difference at all.

Entreri33
11-24-2003, 12:53 AM
I am by no means a N/A expert. I have never heard of actuating the 6 ports electronically. How does that work and is it expensive to set up??

just zip tie them open you'll lose a little lowend torque but you wont notice after a while. Also remove the lower throttle body halves you will get a huge incress in throttle responce.

SoloKK
12-04-2003, 02:50 PM
I have the Gt Spec from Apex on my 94 FD and it dynos significantly higher HP's than my racing beat catback and my tanabe. This is the largest production catback exhaust on the market for the FD's and is definitely at the top in terms of performance.

89Turbo944
12-14-2003, 05:38 PM
Originaly posted bydayna240sx, I wouldnt go with that exhaust. It is way too ricey. You can here the turbos when they kick in? Big deal, I hear my turbo spool at idle.

Plz explain how your turbo spools at idle. From what i know about turbos it that they dont spool at idle. Not enough exhaust pressure. So how do your spool at idle?

dayna240sx
12-14-2003, 06:34 PM
I've got a ton of exhaust pressure between the engine and the turbo itself and no pressure downstream of the turbo.

89Turbo944
12-14-2003, 10:21 PM
OK well right now i think its a bunch of bs.

If you have exhaust pressure befoer the turbo and none after then your turbo is sezed. The turbo works on exhaust pressure, it will not spool if it cant get the pressure through it. And hering a turbo spool at idle is VERY unlikly. A turbo becins to win when the RPM's of the turbo reach 10,000 rpm.

So i think you are full of shit. Plz prove me wrong and i will retract that statment.

dayna240sx
12-15-2003, 03:59 AM
What port do you have on your engine, and what exhaust do you have on your engine? I have a big street port on my engine and a racing beat 3 inch downpipe. And the idle's been raised close to 1,500 rpm. If you had a similar setup, you'd experience similar effects.

SR20DETpower
12-15-2003, 10:14 AM
:owned:

:biggrin:


If a turbo would make noise at 10,000rpm..... It would make noise at 100rpm......also it would make noise at 1,000,000,000 rpm as well LOL. The actual turbine is still moving when it gets the exhaust gasses moved accross it, think of it as a windmill. with 5mph wind it might still move but not be as effective if the wind was 25mph, that is basically what turbo lag is. You need more velocity from the gasses to move the turbine at a faster rpm so the compressor begins to compress air more then atmospheric pressure. Turbo lag is not nessecarily taken care of by higher rpm's. It depends on a few more factors then that alone. The more displacement you have the more exhaust velocity to push the turbine, for instance.... with t4 on a honda civic it might be 4 or 5k before you get full boost. But on a deisel the engine's redline might only be 4k rpm, the engine is making more exhaust then the civic's engine at say 1500rpm so the turbine wheel is moving more rapidly.

89Turbo944
12-15-2003, 04:33 PM
I've got a ton of exhaust pressure between the engine and the turbo itself and no pressure downstream of the turbo

^said by dayna240sx

Unfortunatly im not owned:)

I know that a turbo will spool at low rpms, such as in a desiel truck. The point im making is that if you have no pressure downstreeom of the turbo then its all bs.

What you are telling me is that you are making boost from the exhaust pressure that you have but none of that pressure is making its way through the turbo. Kinda strange.

SR20DETpower what are you rambling on about? Were not talking about desiel trucks to begine with. Were talking about an rx7, 1.3 liters of displacement. Not like a desiel truck. What im trying to say is that most turbos wont be hurd at low RPM's. The turbo in a factory RX7 cant really be hurd from idle. Shur if you open the hood and stick you head in the general area of the turbo im shur you could hear it.

Im saying that a turbo spooling at idle most likly cant be heard. But i could be wrong.

SR20DETpower
12-15-2003, 08:02 PM
from the way you understand concepts and talk about turbos I assumed you knew very little and I explained some to you, sorry for my mistake at helping out. The deisel engine rambling is a comparison, almost like a metaphor. Sorry you know it all i won't talk to ya anymore ill just let you rot away under your bridge.

dayna240sx
12-15-2003, 08:05 PM
I've got a ton of exhaust pressure between the engine and the turbo itself and no pressure downstream of the turbo

^said by dayna240sx

Unfortunatly im not owned:)

I know that a turbo will spool at low rpms, such as in a desiel truck. The point im making is that if you have no pressure downstreeom of the turbo then its all bs.

What you are telling me is that you are making boost from the exhaust pressure that you have but none of that pressure is making its way through the turbo. Kinda strange.

The turbo in a factory RX7 cant really be hurd from idle. Shur if you open the hood and stick you head in the general area of the turbo im shur you could hear it.

Im saying that a turbo spooling at idle most likly cant be heard. But i could be wrong.

All of the exhuast pressure is making its way through the turbo. I'm not going to argue about my car. If you dont believe me, I really dont care.

"shur", "hurd" Where the hell are you from?

89Turbo944
12-15-2003, 08:10 PM
Its not that i dont beleave you its just that it sounds weared to me. i have heard many weared things with cars. Many far stranger than what you said.

PS SR20DETpower, i never ment to insult you knowledge about turbocharging, i just did not see how the fact that a deisel trucks turbo spools at low rpms.

O and im from Vancouver Canada:)

dayna240sx
12-15-2003, 08:20 PM
Its not that i dont beleave you its just that it sounds weared to me. i have heard many weared things with cars. Many far stranger than what you said.

PS SR20DETpower, i never ment to insult you knowledge about turbocharging, i just did not see how the fact that a deisel trucks turbo spools at low rpms.

O and im from Vancouver Canada:)


lol that explains it. All your canadians are crazy :)

I wish there was a way to show you or take a microphone to let you listen to my car.

BTW, tell me a little about your rx3... I want one bad.

89Turbo944
12-15-2003, 08:25 PM
Well at this time its not running. i picked it up last summer from a lady who had it sitting in her drivway for a year or so. Its painted blue right now. It has gold mesh wheels on it, need lots of work. Definetly a rebuild. I picked it up for $1000CDN, so $750 USD or so. Looks awsome. I plan on rebuilding the motor, the paint is in remarkable condition so i might leave it. No rust what so ever. Should be a fun car.

But yes us Canadians are CRAZY:)

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