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Topic: Exhaust Tone / Backpressure (Read 1598 times) previous topic - next topic

Exhaust Tone / Backpressure

My friend's dad brought something up that concerned me a little bit.  He said whenever my car takes off, he hears only a whoosh sound and no exhaust.  He suggested that my current exhaust system might not be enough flow for the boost I am making. 

I didn't think much of it at first, but now other people with turbo cars are telling me that all they can hear is that same compressed air sound with no exhaust note. 

I have a stock single pipe with a flow through magnaflow.  Has anyone else experienced this problem?  None of my other 2.3s had this issue, then again... they didn't have exhaust!

Any help is appreciated!
2013 Focus (Daily)
1968 Cougar XR7
1987 Turbo Coupe
5 Speed, Stock IHI, Aeromotive 340LPH, Stinger 3in DP w/Magnaflow 3in Race Series ler, Hallman Boost Controller, Corbeau Fixed Back Racing Seats, Rebuilt 35# Injectors, Kirban AFPR, Stinger's Front Mount Piping w/Big NPR Front Mount IC, 3/8 E-85 Fuel Lines, SPEC Stage 3+ Clutch, Explorer 4.0 Dual Core Radiator, Optima Red Top Battery
1988 Turbo Coupe (RIP)
1984 Cougar (RIP) :cougarsmily:
1986 Cougar XR7 5 Speed.  (sold)

Exhaust Tone / Backpressure

Reply #1
Well that turbo should give you all the back pressure you need. Also, with a turbo car you want a free flowing exhaust with a high flow ler like a dynomax, or glass pack. Chamberd lers give you the chug, but the turbo don't like that as much as a straight threw setup. Your new exhaust sound is because there's less chug, and more hot exhaust gas flowing out with less resonantion. I hope this made sense, I'm pretty bad at explaining things lol.

Exhaust Tone / Backpressure

Reply #2
That actually made perfect sense.  It seems I need bigger exhaust though.  I am switching to 3 inch off the 2.5 downpipe tomorrow.  It will stop about midway on the passenger side door.  The stock size is just not enough for what I am pushing now. 

I ran a few passes in Pueblo Colorado last night (5000ft Altitude 1/4 Mile)

Best was a 16.00 at 87.7 MPH  Tires are old bald street tires and I spun through 2nd and chirped 3rd.  So, tomorrow I am going to do the exhaust, tires, and a special treat that I have in store for the forum. :)

Nothing special, but it's unique.
2013 Focus (Daily)
1968 Cougar XR7
1987 Turbo Coupe
5 Speed, Stock IHI, Aeromotive 340LPH, Stinger 3in DP w/Magnaflow 3in Race Series ler, Hallman Boost Controller, Corbeau Fixed Back Racing Seats, Rebuilt 35# Injectors, Kirban AFPR, Stinger's Front Mount Piping w/Big NPR Front Mount IC, 3/8 E-85 Fuel Lines, SPEC Stage 3+ Clutch, Explorer 4.0 Dual Core Radiator, Optima Red Top Battery
1988 Turbo Coupe (RIP)
1984 Cougar (RIP) :cougarsmily:
1986 Cougar XR7 5 Speed.  (sold)

Exhaust Tone / Backpressure

Reply #3
Wait.....what size downpipe are you running?
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Exhaust Tone / Backpressure

Reply #4
The stock downpipe on an IHI.
2013 Focus (Daily)
1968 Cougar XR7
1987 Turbo Coupe
5 Speed, Stock IHI, Aeromotive 340LPH, Stinger 3in DP w/Magnaflow 3in Race Series ler, Hallman Boost Controller, Corbeau Fixed Back Racing Seats, Rebuilt 35# Injectors, Kirban AFPR, Stinger's Front Mount Piping w/Big NPR Front Mount IC, 3/8 E-85 Fuel Lines, SPEC Stage 3+ Clutch, Explorer 4.0 Dual Core Radiator, Optima Red Top Battery
1988 Turbo Coupe (RIP)
1984 Cougar (RIP) :cougarsmily:
1986 Cougar XR7 5 Speed.  (sold)

Exhaust Tone / Backpressure

Reply #5
Well you came to the right guy. I build TURBO COUPES thats what i do. What you need is a 3" down pipe into a 3" high flow cat. Then reduce it to 2 1/2" Back from their. Never run a ler with this setup and make sure it runs the full length of the car and out the tail. If you can install a full 3" all the way back its even better but its hard to do. And do not run duels. Turbos do not like BACK PRESSURE.  Good luck Tom
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

Exhaust Tone / Backpressure

Reply #6
Thanks for the straight-forward answer Tom! :)  I am actually going to get a 3 inch system fabbed up today.

btw I have brand new 255/60/15s in the back now.

I am going to the track again on friday and I will let ya'll know how it goes
2013 Focus (Daily)
1968 Cougar XR7
1987 Turbo Coupe
5 Speed, Stock IHI, Aeromotive 340LPH, Stinger 3in DP w/Magnaflow 3in Race Series ler, Hallman Boost Controller, Corbeau Fixed Back Racing Seats, Rebuilt 35# Injectors, Kirban AFPR, Stinger's Front Mount Piping w/Big NPR Front Mount IC, 3/8 E-85 Fuel Lines, SPEC Stage 3+ Clutch, Explorer 4.0 Dual Core Radiator, Optima Red Top Battery
1988 Turbo Coupe (RIP)
1984 Cougar (RIP) :cougarsmily:
1986 Cougar XR7 5 Speed.  (sold)

Exhaust Tone / Backpressure

Reply #7
I was just in Colorado Springs last weekend. Too bad I didn't see any of your cars driving around.
"Real cars dont power the front wheels, they lift them"
[SIGPIC][/SIGPIC]
1984 Mercury Cougar GS 5.0:cougarsmily: BBK Equal Length Shorties, BBK O/R X-Pipe, Magnaflow Magnapacks, Mustang GT Stainless Tailpipes, 18" Magnaflow Rolled Edge Tips. Turbo Coupe Hood, Mach 1 Chin Spoiler. 17"x9" Cobra R's, Falken Ziex 255/50s, and 245/45s.
1984 Ford Thunderbird 3.8L "Drag Queen"
2009 Dodge Ram 1500 Lone Star Edition 5.7L Hemi 400hp, lex DOD14M Magnaflow retro-fit ler kit

 

Exhaust Tone / Backpressure

Reply #8
To be honest they're not much to look at.  My daily just got rearended by someone with no insurance and I had to replace the trunk and rear bumper with my white car.  My 84 cougar was totaled by hail in 2008...

Are you coming back up for the Hill Climb?  If so, we are going to be at engineers corner if you want to meet up.
2013 Focus (Daily)
1968 Cougar XR7
1987 Turbo Coupe
5 Speed, Stock IHI, Aeromotive 340LPH, Stinger 3in DP w/Magnaflow 3in Race Series ler, Hallman Boost Controller, Corbeau Fixed Back Racing Seats, Rebuilt 35# Injectors, Kirban AFPR, Stinger's Front Mount Piping w/Big NPR Front Mount IC, 3/8 E-85 Fuel Lines, SPEC Stage 3+ Clutch, Explorer 4.0 Dual Core Radiator, Optima Red Top Battery
1988 Turbo Coupe (RIP)
1984 Cougar (RIP) :cougarsmily:
1986 Cougar XR7 5 Speed.  (sold)