wow..the Flowmaster exhaust really sucks
- Thread starter 84gnguy
- Start date
I picked up about 6whp replacing my 3" flowmaster with an old straight through dual 2.5" design by TH. It felt like a lot more from the increased spool but peak power was not increased very much. This was at approx 460whp. So dont expect much mph gain swapping exhausts. We had an unopened engine trap 122mph through the stock exhaust.
Dont be too sure of that.
meaning the factory muffler is more restrictive than the Flowmaster stock replacment?
This is the system I just removed:
85-87 GRAND NATIONAL / T-TYPE AXLE-BACK EXHAUST SYSTEM - eBay (item 330476454818 end time Nov-22-10 14:50:58 PST)
its not the flowmasters fault its the customers who buy the wrong muffler then cries about it. I dont have time to address this again in its entirety, but try picking the RIGHT flowmaster before you ASSUME all their mufflers suck, anyone who says that is stupid. flowmaster has the newest exhaust muffler period in the world, while most other world wide exhaust companies are still riding the on the piggy backs of perforated and louvered cores. do some homework before you cry about flowmaster. stay american as much as you can, flowmaster or spintech!
at least test flow test or dyno test your mufflers before crying about them.....this is what happens when you build your car like honda guys, by doing
what magazines tell you to do. dun worry its just a mean way of saying don't rely or trust what your reading in those mags as facts that will apply universally to all including you. DO your own tests and experiments and net your own results.
run two flowmaster outlaw mufflers then try to complain they don't flow......I can stick my arm through them
at least test flow test or dyno test your mufflers before crying about them.....this is what happens when you build your car like honda guys, by doing
what magazines tell you to do. dun worry its just a mean way of saying don't rely or trust what your reading in those mags as facts that will apply universally to all including you. DO your own tests and experiments and net your own results.
run two flowmaster outlaw mufflers then try to complain they don't flow......I can stick my arm through them
Meaning you will probably not pick up 35hp replacing the factory muffler or any muffler for that matter.
..does that apply to people that bought a turbo Buick that already had a previously installed axle back Flowmaster system? :wink:
I have Flowmasters on another one of my cars (non turbo Buick) and am very happy with their performance at the track.
the car in the article claimed a 35 HP pickup from swapping the stock,2.25" exhaust with the single transverse muffler to the Pypes 2.5" system w/2 mufflers.
True but I believe that the new exhaust system too advantage of the other mods that were done.... changing an exhaust on a stock for stock GN will not give you those gains :smile:
I agree 100%
Flowmaster
On my stock GN the factory muffler rotted out internally so i was forced to buy an exhaust. I ran the car at the track and ran 12.70s@ 107. Went and replaced my the exhaust with the force 2 flowmaster kit. I wanted to remain that stock quiet sound. Took the car back to the track and it ran the same numbers. The flowmaster kit actually was a tad quieter then the factory exhaust. Mods to the GN were test pipe, chip,KN,hotwire kit and reds xp pump, 275/50/15 radial T/As.
My buddy had the same build except a hooker cat back like the pypes kit
and 9 inch Art Carr converter. His car ran 12.90-13.00 flat. His car had a very terrible drone. Sucked to ride with him in his car.
The flowmaster kit didnt make anymore HP nor did it take any away from my mild set up.
The magazines are paid to promote products,thats how they pay their bills.
On my stock GN the factory muffler rotted out internally so i was forced to buy an exhaust. I ran the car at the track and ran 12.70s@ 107. Went and replaced my the exhaust with the force 2 flowmaster kit. I wanted to remain that stock quiet sound. Took the car back to the track and it ran the same numbers. The flowmaster kit actually was a tad quieter then the factory exhaust. Mods to the GN were test pipe, chip,KN,hotwire kit and reds xp pump, 275/50/15 radial T/As.
My buddy had the same build except a hooker cat back like the pypes kit
and 9 inch Art Carr converter. His car ran 12.90-13.00 flat. His car had a very terrible drone. Sucked to ride with him in his car.
The flowmaster kit didnt make anymore HP nor did it take any away from my mild set up.
The magazines are paid to promote products,thats how they pay their bills.
Flowmasters versus flow-through designs
My GN has an ATR Pitbull exhaust, straight through mufflers. Its a tad loud and with no cat the drone at freeway speeds can be bothersome. (Crank-up the stereo to compensate) No doubt the flow through design allows faster spooling at virtually any speed.
Now, on the other hand, my MCSS has a "mild" 355, with 3" mandrel bent true-duals and flowmaster 40's. Less drone than the ATR (possibly because flowmaster was designed with the pulsation-cancelling in mind to make constant RPM cruising bearable) At least thats what I recall the flowmaster reps pitching to us in the early 1990's when I worked retail auto parts.
Both cars use 3.42 gears and a 200-4R trans and the SS has a 27" tall rear tire, the GN has a 26" tire, so little effect on freeway cruise RPM. I try to cruise both cars at about 1800-1900 RPM on the freeway here as they seem to behave better than at 1600-1700 RPM that nets me 55-60MPH
I dont have dyno numbers, but I can say both exhaust systems have thier market, and thier place in those markets. I wouldnt put flowmasters on the GN, and wouldnt put the ATRs on the SS... Would magnaflows do better on the SS?.. maybe, but if I had to tolerate the drone, I'd take them back out.
For the intent of a straight through muffler for a turbo car, no doubt the way to make power by reducing restriction. Flowmaster does its job too, allowing better flow characteristics while also cancelling sound pulsations at cruise speed...
My GN has an ATR Pitbull exhaust, straight through mufflers. Its a tad loud and with no cat the drone at freeway speeds can be bothersome. (Crank-up the stereo to compensate) No doubt the flow through design allows faster spooling at virtually any speed.
Now, on the other hand, my MCSS has a "mild" 355, with 3" mandrel bent true-duals and flowmaster 40's. Less drone than the ATR (possibly because flowmaster was designed with the pulsation-cancelling in mind to make constant RPM cruising bearable) At least thats what I recall the flowmaster reps pitching to us in the early 1990's when I worked retail auto parts.
Both cars use 3.42 gears and a 200-4R trans and the SS has a 27" tall rear tire, the GN has a 26" tire, so little effect on freeway cruise RPM. I try to cruise both cars at about 1800-1900 RPM on the freeway here as they seem to behave better than at 1600-1700 RPM that nets me 55-60MPH
I dont have dyno numbers, but I can say both exhaust systems have thier market, and thier place in those markets. I wouldnt put flowmasters on the GN, and wouldnt put the ATRs on the SS... Would magnaflows do better on the SS?.. maybe, but if I had to tolerate the drone, I'd take them back out.
For the intent of a straight through muffler for a turbo car, no doubt the way to make power by reducing restriction. Flowmaster does its job too, allowing better flow characteristics while also cancelling sound pulsations at cruise speed...
I have had ATR Pitbulls on all 3 of TR's. Cant beat the sound or performance.
- Joined
- Feb 18, 2006
You like the sound of a chainsaw.
Jealous?
What do you have? Autozone Cherry Bombs?
Go beat on your drums....
pitbulls are 'straight through designed' not purely straight through. they still just used, like everyone else, a 50 year old perforated core designed muffler with 1000 holes and packing material for sound reduction. packing material rots over time so does the steel they used.
NA vs Turbo same muffler is not a good way to gather data or to generate assumptions for mufflers. for not all mufflers from the same manufacturer are the same
Why wouldn't you put flowmasters on a gn again? It helps when you buy the RIGHT flowmaster instead of assuming simply 'flowmaster isn't for my GN" because so many other countless foo foo's have bought the WRONG flowmaster then cried about it.
Magnaflow is the same 50 year old designed muffler using a perforated core design.
It really sucks when so many flowmaster myths never die no matter how many times its gone over.
IF they are "myths" then please provide the factual data to disprove the "myth".
What is the "right" flowmaster for my application?
Flowmaster pitched the catback system for the GN claiming xx HP increase over stock. They never compared against the other brands, though as other brands came to market they compared to FM and determined thier product made more power than the Flowmaster for this turbo application.. (and a few others)
Notice now that flowmaster no longer provides a part number for a catback system for the TR. If it worked and made the most power they would still be marketing it.
Ive never seen a gain like that on any TR. Dynoed and seen plenty dynoed with different exhausts dump open/not open and never saw anything close to 35whp. Not that it couldnt pick up 35 if there was a big problme with what was on the car like collapsed baffles, its just that most wont pick up more than 10whp even if they are heavily modded and have an ex system that would seem to be restrictve. It isnt what it seems. Those are some outrageous claims imo. Weve dynoed a car with stock ex and opened the ex and it didnt pick up anywheere near that and it went 122mph in the quarter through it. Much more power than the car in the article. Dual 2.5" are the most tolerable from what ive seen. Single ex with straight through muffler turns the car into a torture chamber
Trying to recall what FM pitched to us in the late 80's when I worked automotive retail, and from what my old mind can recall, it was under 10HP (7.7 or 5.5 comes to mind) over the OE setup.
Of course, I was just out of HS in that era and could not afford a car like a GN, not shuffling parts at a parts store here....
I did however pay a lot of attention to what the mfg's reps were saying regarding products and compared that to the real world experiences customers had.
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