[bsblguy]

My '69 GTO 400/350 has stock manifolds with 2 1/2 pipes into flowmasters. If I change to ram air manifolds will I notice the difference? This is just a cruise nite/ car show car no track. I do like performance though. I'm also thinking of installing x pipe as it's straight thru now and maybe change mufflers or add resonators as it's too loud and has a drone at 45 or above. Love the sound at idle though. Thoughts without spending a lot of money?

[b-man]

You likely won't notice the difference between stock log manifolds and HO/Ram Air manifolds on a stock or near stock engine. Less than a 10 HP difference.

Use your cash to get rid of the Flowmasters and install an X-pipe system with Race-Pro mufflers from PYPES.

[David Jones]

Changing from what you have to RAIII manifolds also requires new downpipes...or another cost involved.

I had the 50 series Flowmasters on my 69 and holding a conversation while driving around was impossible. I swapped on a pair of DynoMax Super turbo's (17749) and all is quiet inside the car now. My pipes are also Flowmaster brand 2.5".

[b-man]

I have used the 17749 Dynomax mufflers on a few cars and really like them too. The Race-Pro mufflers are a straight-thru design and are surprisingly quiet until you nail the throttle, I used them to replace some Flowmaster race mufflers and the performance was the same.

[Blued and Painted]

Originally Posted by bsblguy

Thoughts without spending a lot of money?

Once you add up the RA manifolds, their down pipes, the hardware and gasket kit, you could buy some ceramic coated Hooker's or Dougs full length headers. Then still wont get much preformance gain on a stock engine. JMO.

X2 on the dynomax turbo.

[bsblguy]

I am going to do the x pipe. I know someone that has the manifolds i can get used but think i'll pass on those. Don't want to do headers on this car. Talked to pypes at auto fair last month and he said to use street pros but reading this forum i hear that race pros are quieter, so confusing. Love the rumble with the flowmasters at idle, how do the dynomax sound?

[goatless]

Originally Posted by b-man

You likely won't notice the difference between stock log manifolds and HO/Ram Air manifolds on a stock or near stock engine. Less than a 10 HP difference.

Use your cash to get rid of the Flowmasters and install an X-pipe system with Race-Pro mufflers from PYPES.

What he said!
BTW, I just installed the Race-Pro mufflers on my Lemans (replacing 10 year old Street-Pros) and was shocked that they were quieter even though you can look straight through them and see out the other side. Nice rumble at idle without that raspy sound. And they sound great at full song!

[goatless]

Forgot to add- I have the Dynomax Super-Turbos on my Bonneville 428 with a Pypes 2 1/2" X system and they are QUIET! Fine for for a Bonneville wagon, but a little quiet for my taste for anything else.

[bsblguy]

I don't want it totally quiet. What do the race pros sound like at say 45 and 70 mph? I want good sound at idle but not so much noise at speed.
What about adding resonators, would that quiet it down at speed but keep a good sound at idle? Or at least get rid of the drone?

[lust4speed]

I know that they have made many improvements to the packing materials, but wonder what the life span is of a muffler with packing? Having replaced glass-packs every 10 to 12 thousand miles in the 1960's, I'm a little gun shy.

[bsblguy]

I put the dynomax 17749 mufflers on and I can hear myself think now when driving on the freeway. So far I' m happy with them. My neighbors like me better too.

[PontGuy]

The 17749's are amazingly quiet- with RA manifolds and X-pipe my Lemans vert is no louder than my stock 06 GTO, which is exactly what I wanted after years of putting up with the Flowmaster noise and drone. I ran some test passes at the drag strip and believe it or not my wife actually complained that the car didn't sound fast, regardless of what the timeslips said! I think they are great mufflers, but not if you are looking for a real "performance" sound.

No regrets on installing the RA manifolds, but mostly because I like the way they look under the hood.

[AG]

I have RA manifolds on my '72 LeMans and 17749s. Probably get a few horses over manifolds but the curb appeal did it for me.

[Pontirag]

there was an article written about comparison between the standard manifolds, the ra manifolds and headers in one of the pontiac mags afew years back.

the ra'a were quite a bit more efficient than standard manifolds and came within about 15-20 % of the efficientcy of headers.

But that only tells part of the story. Some header designs and current ones especially are more efficent now, and also its not just a matter of bolting on an exuaste system and doing a comparrison. Some additional tuning is required that may make headers more efficient under certain conditions.

So, it may seem like an apple vs apples comparison but explored to its limits it kinda becomes an apples vs oranges comparison.

RA'a are quieter and cause few clearance problems. they cost only a bit less than some basic headers.

cast iron has a different co-efficient of expansion than aluminum used in heads so gasket sealing may pose some issues.

[Radman]

Originally Posted by bsblguy

I am going to do the x pipe. I know someone that has the manifolds i can get used but think i'll pass on those. Don't want to do headers on this car. Talked to pypes at auto fair last month and he said to use street pros but reading this forum i hear that race pros are quieter, so confusing. Love the rumble with the flowmasters at idle, how do the dynomax sound?

I have a thread on this section titled 389 sound. The exhaust is a Pypes 2.5 inch with the X pipe. The mufflers are Summit Racing turbos, that are very close to the dynoflow turbo mufflers. Just listen to my sound and you will have a good idea of the X pipe and turbo mufflers.

[Radman]

I forgot to say that I ran the engine up to 4,000 RPM with the camera at the rear of the car and while inside the car. The exhausts exit the car on the side just behind the rear wheels.

[PONTIAC-ONE]

Ram Air manifolds look cool and do ad some performance, thats enough reason for me. I have the R/A restoration manifolds with 2 1/2" dumps on my 455 and there was a noticeable gain from the logs. I have the Street Pro mufflers, I don't trust the Race Pro packing to last very long.

[71 T/A]

I have the Dynomax VT mufflers on my near stock 69 GTO and the car is fairly quiet with no drone at all like Dynomax claims.

[GT182]

I've got a 2 1/2" Walker system with an H-pipe but run Cherry Bombs. They're quieter than the Flow Masters and Pypes mufflers, but still have that nice mellow sound. And when you downshift and backoff on the gas.... that great popping sound comes thru. I've ran the Cherry Bombs for years on my cars back in the 60s and 70s, and never had a problem with them 'wearing' or rusting out.

Too me the Pypes mufflers are just too loud when you're going thru the gears. And that droning sound from drives me nuts.

[PONTIAC-ONE]

Originally Posted by GT182

I've got a 2 1/2" Walker system with an H-pipe but run Cherry Bombs. They're quieter than the Flow Masters and Pypes mufflers, but still have that nice mellow sound. And when you downshift and backoff on the gas.... that great popping sound comes thru. I've ran the Cherry Bombs for years on my cars back in the 60s and 70s, and never had a problem with them 'wearing' or rusting out.

Too me the Pypes mufflers are just too loud when you're going thru the gears. And that droning sound from drives me nuts.

I have a X over with a Pypes 2 1/2" full system out the back and there is NO drone with my Street pros and the Ram Air manifolds.
X vs H pipe changes the tone, so does headers vs manifolds.

Back to the original posters topic, get the Ram Air manifolds, you'll be happy with them!