HP differences for RB 2.5/3" turboback?
#1
Rotary Freak
Thread Starter
Join Date: Aug 2001
Location: Ottawa, Ontario
Posts: 2,788
Likes: 0
Received 0 Likes
on
0 Posts
HP differences for RB 2.5/3" turboback?
Specifically for the turbo, I know the 3" is 58hp for the full system, but what about the 2.5" one?
Thanks!
-Ross
Thanks!
-Ross
#6
Rotary Freak
Thread Starter
Join Date: Aug 2001
Location: Ottawa, Ontario
Posts: 2,788
Likes: 0
Received 0 Likes
on
0 Posts
since the turbo outlet on the stock s5 is only 2.5" in diameter, wouldn't it make sense to stick with a 2.5" exhaust? I don't plan on upgrading the turbo to anything more than a s5 60-1 hybrid. And frankly, a 3" exhaust would be a waste of money for me at this point.
Should i just stick with racingbeat 2.5" components? I already got the dp/ps.
Thanks guys!
-Ross
Should i just stick with racingbeat 2.5" components? I already got the dp/ps.
Thanks guys!
-Ross
Trending Topics
#8
Senior Member
iTrader: (2)
Join Date: Jun 2003
Location: FWTX
Posts: 600
Likes: 0
Received 0 Likes
on
0 Posts
a 3" exhaust would be a waste of money for me at this point.
On my 87 TII, I have the 80mm (Full RB exhaust) DP, into a 3" cat, into a 3" Borla muffler that splits off into 2 2.5" pipes.
3" is really the most efficient diameter piping for the TII, I would think 2.5" turbo back would still be pretty restrictive (although it wouldn't have any cats...).
#10
wish my car was faster...
Join Date: May 2003
Location: flower mound, tx
Posts: 476
Likes: 0
Received 0 Likes
on
0 Posts
is that like a dyno proven HP figure? cause 58 hp is a lot of damn hp for a turbo, or is it just becuase its less restrictive and naturally makes the car run higher boost, and therefore you would need the fuel cut defencer? if this is the case, then i wont go for the RB exhaust, cause any exhaust with the same pipe diameter should do the same.
any nice quiet exhausts out there that still make a decent amount of power? i think im getting to old for very loud cars, lol (im 19) even though loud=fast
any nice quiet exhausts out there that still make a decent amount of power? i think im getting to old for very loud cars, lol (im 19) even though loud=fast
#15
Rotary Enthusiast
Join Date: Aug 2002
Location: Kansas
Posts: 1,273
Likes: 0
Received 0 Likes
on
0 Posts
Is that RB 3" exhaust a "true" 3"? I mean, it doesn't like taper down to 2.5" at the end of the DP does it?
Also, anyone happen to have any sound clips of this 3" exhaust on a turbo?
Also, anyone happen to have any sound clips of this 3" exhaust on a turbo?
#17
Junior Member
Join Date: Feb 2003
Location: Eugene, OR USA
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
On an additional note for original poster, You really cannot have too little backpressure for a turbo engine(power wise). People run open downpipe at the drag strip for this reason. Sound is a more subjective measurement. How much sound is acceptable for what increase in power. The flat out truth is that less backpressure is more power. NA (piston engines at least) need a little backpressure for exhaust scavaging and such, but turbo motors have enough blockage (in the form of a turbo) to have all the backpressure they need, and then some.
GREG
GREG
Last edited by Simplecat; 09-02-03 at 11:28 PM.
#18
Senior Member
iTrader: (2)
Join Date: Jun 2003
Location: FWTX
Posts: 600
Likes: 0
Received 0 Likes
on
0 Posts
Is that RB 3" exhaust a "true" 3"? I mean, it doesn't like taper down to 2.5" at the end of the DP does it?
As for the sounds Trav, imagine you TII stock, with a little more growl, but VERY QWIET at idle.
#19
Rotary Freak
Thread Starter
Join Date: Aug 2001
Location: Ottawa, Ontario
Posts: 2,788
Likes: 0
Received 0 Likes
on
0 Posts
Bump for some more insight
What kind of HP differences are we talking about though?
if the turbo outlet is 2.5", wouldn't that mean that anything bigger would only add turbulence when going to a different size?
What kind of HP differences are we talking about though?
if the turbo outlet is 2.5", wouldn't that mean that anything bigger would only add turbulence when going to a different size?
#20
Rotary Freak
Thread Starter
Join Date: Aug 2001
Location: Ottawa, Ontario
Posts: 2,788
Likes: 0
Received 0 Likes
on
0 Posts
Bump for some more insight
What kind of HP differences are we talking about though?
if the turbo outlet is 2.5", wouldn't that mean that anything bigger would only add turbulence when going to a different size?
What kind of HP differences are we talking about though?
if the turbo outlet is 2.5", wouldn't that mean that anything bigger would only add turbulence when going to a different size?
#21
Yar-Har-Har
Join Date: Sep 2002
Location: Nashville, 37217
Posts: 1,954
Likes: 0
Received 0 Likes
on
0 Posts
someone asked about dyno'd #'s and im pretty sure they have dynoed it and have it available on thier site...
i just got the 3' DP for my TII, and i cant wait to attach it....LOOKS FRIGGIN HUGE!!
i just got the 3' DP for my TII, and i cant wait to attach it....LOOKS FRIGGIN HUGE!!
#23
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 31,145
Received 2,799 Likes
on
1,981 Posts
i dynoed my car with and without the rb turbo back, and it did 214 with and 220 without, the dyno is accurate to +/-5 hp so the rb stuff works.
mike
mike
#24
Senior Member
Join Date: Feb 2001
Location: Montgomery, Al.
Posts: 724
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by TooMuch4You
Slap me if this is a dumb question (i'm kinda new), but would you need fuel mods before slapping this exhaust on?
Slap me if this is a dumb question (i'm kinda new), but would you need fuel mods before slapping this exhaust on?
Personally, I think the best investment any turbo RX-7 owner can make is to purchase a complete stand alone ECU before they upgrade anything else. But if you don't plan on going any further than what the stock turbo and intercooler can give you then that might almost be a bit of overkill.
#25
Full Member
Join Date: Mar 2002
Location: Irving, Tx
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by j9fd3s
i dynoed my car with and without the rb turbo back, and it did 214 with and 220 without, the dyno is accurate to +/-5 hp so the rb stuff works.
mike
i dynoed my car with and without the rb turbo back, and it did 214 with and 220 without, the dyno is accurate to +/-5 hp so the rb stuff works.
mike