LOUD a** muffler
Senior Member
Joined: 08-29-2007
Posts: 256
From: CenCoast California
Yesterday, I base-lined the car on the chassis dyno at Westech Performance Group in Mira Loma CA. Stock, except for 91-oct pump gas, Red Line 10W30 oil in the engine, Red Line Superlight Shockproof gear lube in the trans and Goodyear Eagle F1 A/S tires, it averaged 139.8-hp@6275 rpm at the wheels, SAE-corrected.
Today, I installed the Flowmaster "Force II" exhaust (PN 17454) for HHRs other than the SS. Out of the box, Flowmaster's typical high-quality, made-in-USA, manufacturing is easy to see. A nice product development touch is that the system is engineered to use all the existing stock muffler hangers which makes the installation all that more easy.
It took about two hours to get it on and, I'd say, that was a long time as, when doing installations for product reviews, work goes slow because: 1) I'm comparing the product's instructions to how the installation actually proceeds 2) I take pictures now and then and 3) unless power tools are required by the product's instructions, I only use hand tools. I thought 2 hrs to put on an exhaust was pretty darn easy. Someone with a Sawzall and an air ratchet will get it done in an hour. An experienced exhaust tech with those power tools will have it on in 30-45-min.
The only issues I had with the instructions was 1) their telling me to cut the exhaust ahead of the muffler--I think a better place is just ahead of the rear axle. That would make getting the old system out even easier than it was for me and 2) whomever wrote the instructions got confused on the front and back of some parts. That said, the installation is pretty straight-forward and only someone who is totally clueless about working on cars is going to need to follow the directions, word-for-word.
The truck needs to be up in the air to do this job so you need a floor jack and jack stands or be working with the car on a lift. Other than that, all that's required is hand tools. All hardware and a new exhaust gasket are included.
Before I installed the Flowmaster exhaust, I opted to have the entire system metallic-ceramic coated by Xtreme Performance Heat Coatings in Oxnard CA. They've been doing all my exhaust coating work for the last 4 or 5 years and, true to form, the parts looked outstanding. The coating's appearance makes you think the system was chromed and, actually, it's better than chrome because it won't turn blue or purple from the head. The coating, also, decreases exhaust heat radiation from the system.
After the exhaust installation, I installed a set of Denso ITV-20 plugs (one range colder than stock) and I put a Green Filter in the stock air box. Actually, I got started on adding the Airaid intake kit but ran into problems with the installation. Until Airaid and I can sort out the problem I'm having, I'll stick with the Green Filter in the stock air box. I'll have more details on that, later.
When I fired up the truck for the first time with the Flowmaster on it, I was pleased with the sort of throaty, but subdued idle. Certainly a bit louder and a more authoritative exhaust note than stock but, I'll admit that it's not a "LOUD assed muffler" of the variety the person who began this thread may have wanted. A brief road test had me liking the sound even more. Yep. It's louder than stock but doesn't put out the obnoxious, blat-blatty "ricer sound". It also doesn't have any sharp, high rpm resonance typical of some of the sport compact performance exhaust systems. Also, there's no interior resonance (common on vehicles with flat floors or long roofs like the HHR) that I could detect, but my brief road test was basically just around the block. Over the next few days I'll put more miles on the car and analyze the sound at highway speeds and higher rpm.
Next Tuesday, it'll be back to Westech for the second dyno session. I'll post the test results as well as some more impressions of the system's sound.
Sources
http://www.westechperformance.com/
http://www.redlineoil.com/
http://www.flowmastermufflers.com/
http://www.densoaftermarket.com/
http://www.xtremeperformanceheatcoatings.com/
Today, I installed the Flowmaster "Force II" exhaust (PN 17454) for HHRs other than the SS. Out of the box, Flowmaster's typical high-quality, made-in-USA, manufacturing is easy to see. A nice product development touch is that the system is engineered to use all the existing stock muffler hangers which makes the installation all that more easy.
It took about two hours to get it on and, I'd say, that was a long time as, when doing installations for product reviews, work goes slow because: 1) I'm comparing the product's instructions to how the installation actually proceeds 2) I take pictures now and then and 3) unless power tools are required by the product's instructions, I only use hand tools. I thought 2 hrs to put on an exhaust was pretty darn easy. Someone with a Sawzall and an air ratchet will get it done in an hour. An experienced exhaust tech with those power tools will have it on in 30-45-min.
The only issues I had with the instructions was 1) their telling me to cut the exhaust ahead of the muffler--I think a better place is just ahead of the rear axle. That would make getting the old system out even easier than it was for me and 2) whomever wrote the instructions got confused on the front and back of some parts. That said, the installation is pretty straight-forward and only someone who is totally clueless about working on cars is going to need to follow the directions, word-for-word.
The truck needs to be up in the air to do this job so you need a floor jack and jack stands or be working with the car on a lift. Other than that, all that's required is hand tools. All hardware and a new exhaust gasket are included.
Before I installed the Flowmaster exhaust, I opted to have the entire system metallic-ceramic coated by Xtreme Performance Heat Coatings in Oxnard CA. They've been doing all my exhaust coating work for the last 4 or 5 years and, true to form, the parts looked outstanding. The coating's appearance makes you think the system was chromed and, actually, it's better than chrome because it won't turn blue or purple from the head. The coating, also, decreases exhaust heat radiation from the system.
After the exhaust installation, I installed a set of Denso ITV-20 plugs (one range colder than stock) and I put a Green Filter in the stock air box. Actually, I got started on adding the Airaid intake kit but ran into problems with the installation. Until Airaid and I can sort out the problem I'm having, I'll stick with the Green Filter in the stock air box. I'll have more details on that, later.
When I fired up the truck for the first time with the Flowmaster on it, I was pleased with the sort of throaty, but subdued idle. Certainly a bit louder and a more authoritative exhaust note than stock but, I'll admit that it's not a "LOUD assed muffler" of the variety the person who began this thread may have wanted. A brief road test had me liking the sound even more. Yep. It's louder than stock but doesn't put out the obnoxious, blat-blatty "ricer sound". It also doesn't have any sharp, high rpm resonance typical of some of the sport compact performance exhaust systems. Also, there's no interior resonance (common on vehicles with flat floors or long roofs like the HHR) that I could detect, but my brief road test was basically just around the block. Over the next few days I'll put more miles on the car and analyze the sound at highway speeds and higher rpm.
Next Tuesday, it'll be back to Westech for the second dyno session. I'll post the test results as well as some more impressions of the system's sound.
Sources
http://www.westechperformance.com/
http://www.redlineoil.com/
http://www.flowmastermufflers.com/
http://www.densoaftermarket.com/
http://www.xtremeperformanceheatcoatings.com/
Senior Member
Joined: 08-28-2008
Posts: 542
From: Houston, Texas
Why would you step back to a colder plug on a N/A vehicle? It's my understanding that colder plugs are for nitrous and adding/increasing boost, and that hotter plugs yield more horsepower for N/A. Your signature leads me to believe that you probably know more about this than I do, so please enlighten me?
Also, are the pictures for a magazine or will you be posting them here?
Also, are the pictures for a magazine or will you be posting them here?
Senior Member
Joined: 08-29-2007
Posts: 256
From: CenCoast California
Why would you step back to a colder plug on a N/A vehicle? It's my understanding that colder plugs are for nitrous and adding/increasing boost, and that hotter plugs yield more horsepower for N/A. Your signature leads me to believe that you probably know more about this than I do, so please enlighten me?
Second, virtually all OE spark plug heat range choices are made with a wide variety of drivers and duty cycles in mind and one thing all car companies must contend with is the possibillity of "pre-delivery fouling". "Pre-delivery" is any operation of the vehicle prior to sale, such as driving it off the line, on and off the truck, moving it around on the lot, short test drives...stuff like that. Much of that kind of operation qualifies as a start without warm-up. When customers take delivery of new cars then soon after experience misfire due to plug fouling because the car was started a bunch of times and never allowed to warm-up (ie: some carbon fouling), they get unhappy. So, to prevent pre-delivery fouling, stock plug choices are often pretty hot.
Third, for a truck that never sees starts without warm-ups and which is sometimes driven pretty hard, there's less chance of detonation if you use a colder spark plug so...for all my street driven cars, I run one range colder than stock.
For the 2.4 Ecotec, the stock heat range is a Denso 16, so I go to a Denso 20.
Also, are the pictures for a magazine or will you be posting them here?
Senior Member
Joined: 08-29-2007
Posts: 256
From: CenCoast California
I've run the truck for about 500 miles so far with the Flowmaster Force II exhaust in place. I continue to like that product.
Earlier I said...
After driving the car for several weeks, I've detected no interior resonance at any speed or rpm.
Under acceleration or light throttle cruise, the Flowmaster is louder than stock at low and low-mid-range rpms. It's about the same as the stock system from the high-mid-range on up to the engine's 7000 rpm rev limit. Interestingly, it's loudest on deceleration/coasting in the low-mid-range. During some of the chassis dyno testing, I stood 20 ft behind the truck to listen and as for how loud, well...like I said before, at lower rpms it's certainly louder than the stock system, but I would not characterize this system as a "loud-assed" muffler. Would I want it louder? Well...yeah, maybe a little louder at high rpm would be ok.
The quality of the sound is typically Flowmaster in that it's a little throaty, certainly more "authoratative" than the stock exhaust, but does not have the sharp and very loud resonance and tinny or "blatty" sound quality typical of "ricer" exhaust systems. Lastly, on sound quality, this truck is driven mostly by my Wife, the Fairest Sandra the Red. In fact, the main reason I put this exhaust on our HHR was because she thought the truck was too quiet. She likes the Flowmaster-equipped HHR's sound.
I talked earlier about the Flowmaster Force II's ease of installation, so I won't waste more time on that other than to add that I've installed three Force II systems on different vehicles in the last several years and this one was, by far, the easiest. Flowmaster really has this bolt-on/clamp-on, cat-back stuff down pat.
As for how it looks, the famed "sort of boxy" shape of the Flowmaster muffler is visible from the back of the car and the Flowmaster exhaust tip has a higher-quality appearance than did the cheap chrome overlay on the stock muffler's tailpipe.
Ok, the numbers....
On the Superflow "Autodyn" chassis dyno at Westech Performance Group in Mira Loma, California, in stock trim, our HHR made 139-hp@6140rpm and 129-lbs/ft torque@5070-rpm. With the Flowmaster exhaust in place, the truck made 142-hp@6230-rpm and 133-lbs/ft torque@4940-rpm. All these numbers are on 91-octane gas, are three-run averages and are SAE-corrected.
So...3-hp SAE at the wheels is adequate for a cat-back exhaust on a 2.4. I'd hoped for 5-hp, but I'm happy with the 3-hp and. more importantly, the 4-lbs at peak torque. On the subject of torque, the Flowmaster is making some noticeable torque improvement in the midrange, way before peak power. For example, at around 4000 rpm, its adding 6-lbs/ft. and from 3750 to 5000 rpm the increase is at least 4.5-lbs/ft.
After the exhaust testing was done, we stuck a Green Filter, an oil-impregnated woven cotton air filter panel, in the stock air cleaner assembly and gained another half a horsepower and 1-lb/ft of torque. Again, that's a 3-run average and SAE-corrected.
I had intended to test the Flowmaster and Airaid intake kit as a "package deal" but I found out after I ordered the parts and tried the installation that the Airaid airbox only fits automatics and not HHRs with five-speed manual transmissions. Airaid tells me that there is a difference in engine angle between autos and manuals and, since the engine is tipped farther back in trucks with manuals, its box interferes with the cowl and doesn't seal properly against the bottom of the hood. Unfortunately, Airaid's Product Manager, Sam Enloe, says the company has no short-term plans to release a specific airbox for five-speeds but they might at some time in the future.
More info:
http://www.westechperformance.com/
http://www.flowmastermufflers.com/
http://www.greenfilterusa.com/
Bottom line on the Flowmaster Force II system:
1) Easy to put on
2) Noticeably louder than stock at low and mid-range rpms.
3) Sounds better overall
4) On the chassis dyno, 3-hp and 4-lbs/ft improvement at peak power and peak torque
Earlier I said...
Also, there's no interior resonance (common on vehicles with flat floors or long roofs like the HHR) that I could detect, but my brief road test was basically just around the block. Over the next few days I'll put more miles on the car and analyze the sound at highway speeds and higher rpm.
Under acceleration or light throttle cruise, the Flowmaster is louder than stock at low and low-mid-range rpms. It's about the same as the stock system from the high-mid-range on up to the engine's 7000 rpm rev limit. Interestingly, it's loudest on deceleration/coasting in the low-mid-range. During some of the chassis dyno testing, I stood 20 ft behind the truck to listen and as for how loud, well...like I said before, at lower rpms it's certainly louder than the stock system, but I would not characterize this system as a "loud-assed" muffler. Would I want it louder? Well...yeah, maybe a little louder at high rpm would be ok.
The quality of the sound is typically Flowmaster in that it's a little throaty, certainly more "authoratative" than the stock exhaust, but does not have the sharp and very loud resonance and tinny or "blatty" sound quality typical of "ricer" exhaust systems. Lastly, on sound quality, this truck is driven mostly by my Wife, the Fairest Sandra the Red. In fact, the main reason I put this exhaust on our HHR was because she thought the truck was too quiet. She likes the Flowmaster-equipped HHR's sound.
I talked earlier about the Flowmaster Force II's ease of installation, so I won't waste more time on that other than to add that I've installed three Force II systems on different vehicles in the last several years and this one was, by far, the easiest. Flowmaster really has this bolt-on/clamp-on, cat-back stuff down pat.
As for how it looks, the famed "sort of boxy" shape of the Flowmaster muffler is visible from the back of the car and the Flowmaster exhaust tip has a higher-quality appearance than did the cheap chrome overlay on the stock muffler's tailpipe.
Ok, the numbers....
On the Superflow "Autodyn" chassis dyno at Westech Performance Group in Mira Loma, California, in stock trim, our HHR made 139-hp@6140rpm and 129-lbs/ft torque@5070-rpm. With the Flowmaster exhaust in place, the truck made 142-hp@6230-rpm and 133-lbs/ft torque@4940-rpm. All these numbers are on 91-octane gas, are three-run averages and are SAE-corrected.
So...3-hp SAE at the wheels is adequate for a cat-back exhaust on a 2.4. I'd hoped for 5-hp, but I'm happy with the 3-hp and. more importantly, the 4-lbs at peak torque. On the subject of torque, the Flowmaster is making some noticeable torque improvement in the midrange, way before peak power. For example, at around 4000 rpm, its adding 6-lbs/ft. and from 3750 to 5000 rpm the increase is at least 4.5-lbs/ft.
After the exhaust testing was done, we stuck a Green Filter, an oil-impregnated woven cotton air filter panel, in the stock air cleaner assembly and gained another half a horsepower and 1-lb/ft of torque. Again, that's a 3-run average and SAE-corrected.
I had intended to test the Flowmaster and Airaid intake kit as a "package deal" but I found out after I ordered the parts and tried the installation that the Airaid airbox only fits automatics and not HHRs with five-speed manual transmissions. Airaid tells me that there is a difference in engine angle between autos and manuals and, since the engine is tipped farther back in trucks with manuals, its box interferes with the cowl and doesn't seal properly against the bottom of the hood. Unfortunately, Airaid's Product Manager, Sam Enloe, says the company has no short-term plans to release a specific airbox for five-speeds but they might at some time in the future.
More info:
http://www.westechperformance.com/
http://www.flowmastermufflers.com/
http://www.greenfilterusa.com/
Bottom line on the Flowmaster Force II system:
1) Easy to put on
2) Noticeably louder than stock at low and mid-range rpms.
3) Sounds better overall
4) On the chassis dyno, 3-hp and 4-lbs/ft improvement at peak power and peak torque
Senior Member
Joined: 06-02-2006
Posts: 1,533
From: Break Away Republic of SoCal
Hib,
I had a 86 Z28 and 94 Formula Firebird with Flowmasters and I loved the sound. Unfortunately
Couldn't find any reference to the kit 17454 on the flowmaster site.
Internet search yielded this from a superchevyBlog
http://blogs.superchevy.com/6278680/...ust/index.html
Is it too soon for FlowMaster to post on their website or did they take it off?
I had a 86 Z28 and 94 Formula Firebird with Flowmasters and I loved the sound. Unfortunately
Couldn't find any reference to the kit 17454 on the flowmaster site.Internet search yielded this from a superchevyBlog
http://blogs.superchevy.com/6278680/...ust/index.html
Is it too soon for FlowMaster to post on their website or did they take it off?
Senior Member
Joined: 08-29-2007
Posts: 256
From: CenCoast California
Hib,
I had a 86 Z28 and 94 Formula Firebird with Flowmasters and I loved the sound. Unfortunately Couldn't find any reference to the kit 17454 on the flowmaster site.
Internet search yielded this from a superchevyBlog
http://blogs.superchevy.com/6278680/...ust/index.html
Is it too soon for FlowMaster to post on their website or did they take it off?
I had a 86 Z28 and 94 Formula Firebird with Flowmasters and I loved the sound. Unfortunately
Couldn't find any reference to the kit 17454 on the flowmaster site.Internet search yielded this from a superchevyBlog
http://blogs.superchevy.com/6278680/...ust/index.html
Is it too soon for FlowMaster to post on their website or did they take it off?
As for sound clips, I'm sorry but I do not have the equipment to properly record the exhaust. As for mileage, we didn't test it because 1) properly testing fuel mileage is a lot of work, 2) in my experience, aftermarket exhausts for road vehicles which are properly designed and correctly installed on an engine which is running right before the installation will either not affect mileage or will offer a slight improvement, ie: if there was a gain, it's modest.
Lastly, on the mileage issue, most people can gain far more through altering ones driving habits than they'll ever gain by bolting on a different exhaust.
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