[455Dave]

sherm455:

I think Jim Hand is trying to politely say that since I don't have any real data ( the loss of the dyno is killing me) that I may have made too many changes without verifying the value of each one and ended up with a bad combo along the way. Jim has counseled me on this before (although he probably doesn't remember that) but it is true that I have swapped out a lot of parts over the years trying different things. The track is fairly close so I have been able to check a lot of changes but not every one. A good friend of mine told me Saturday it's time to re-baseline the car since I've done so much to it since the last trip to the track and work from there.

I think he's just worried the T/A and a 100 shot will give his chebby a run for the money. [img]/infopop/emoticons/icon_biggrin.gif[/img]

I can't explain why my 455 responded the way it did but I suspect the carb has a lot to do with it. I have 8 more on the shelf and I want to install one with a different idle air bleed design because the one on the car is different than all of the others, so I don't trust it. I do have a 750 that ran great before I swapped the exhaust so maybe I should try that one and see if it needs to be jetted up.

If you already have the Flowmaster system, why not install it and see what happens and don't worry about the Dr Gas. I ran mine for years and liked it.

The Hands have given us a lot of real world testing and I appreciate it. I can't think of anyone else who goes to so much effort for the street/strip crowd, which is where I fall into. There's a lot of good info put out on the 10 second and below cars, but for now I have to file that stuff aways and hope I can use it in the future.

Dave

[Jim Hand]

Larry,
It happens that I run the Stainless Steel Ultra Flows because they are the quietest of the performance mufflers we have tested, and flow the best of all normal size mufflers. A less expensive and slightly louder version of the same muffler with equal flow is the "Welded Ultra Flow".

Back pressure is important - after all, the goal of any muffler is to get the exhaust through it with the least possible disruption to flow, while providing the sound control and/or sound level/type appropriate for that specific muffler.

For the best possible review of a large group of mufflers, you really need to purchase the Silent Power CD. We are not involved with the purchase, nor have we received any money from the project (although we hope someday to recoup our production expenses). It provides a wealth of information about mufflers including flow levels, sound levels, costs, dimensions, and sources. And you can hear the real sounds (54 tracks) using a 462" Pontiac with an 041 cam, and with and without the X crossover. Send me an E mail for purchase information. Jim Hand

[Robert Williams]

sherm455, you can get your 2.5 inch downpipes from Torque Tech in Valdosta, GA. They come with the mounting flanges. They fit automatic and 4-gear vehicles. They will fit GM A, F, & G-body vehicles. Part number GMX-42110 @ $109.00 a pair. Specify if you need 2-bolt or 3-bolt mounting flanges, or one each of both. These downpipes are mandrel bent and aluminized. They also have 3" and 3-1/2" exhaust systems for your car. I don't think they have a web-site yet, but you can e-mail them at torque@surfsouth.com Phone Tech Line 1-229-242-0691 and the order line is 1-800-408-0016 Did you pick up that 455 block yet?

[ January 29, 2002: Message edited by: Robert Williams ]</p>

[sherm455]

Robert- Thanks for the tip on the downpipes. Just wondering if anyone local can do this mandrel bending. Haven't been up north yet, blocks inside and not going anywere soon. Too much snow to get to it.

The reason I ask about the rejetting is Cliff R. just finished rejetting my carb, and I forgot to tell him if I was going to use the X-pipe or not. Was hoping it wouldn't make much difference.

I too appreciate the Hand's testing. I have searched the web over the years and found various articles by them that were well written and informative. I liked there Street Machine Basics articles. They have contributed significantly to the Pontiac hobby and I hope they continue. [img]/infopop/emoticons/icon_smile.gif[/img]

[Larry Navarro]

torquetech site
http://torquetechexh.com/users/kblyt...h/Page_1x.html

[Larry Navarro]

Flowmaster 42582, 2.5" Flowed 55% of open 2.5" pipe.

jim or tom...this the transverse muffler, right?

[Robert Williams]

sherm455, Tucci Engineering in Marcy could make the downpipes, but he would need the car, he builds street rods. 733-9615. It would be easy to just order them from Torque Tech, but that's your call. Larry thank you for the Torque Tech web-site.

[Jim Hand]

455 Dave: No hidden message! But thanks to you and others for the comments about our material - they are appreciated.

And thanks to all for posting your exhaust component experiences and other good info about the subject. We all learn from real "on the road/track" data!

Larry N. Yes, the FM 42582 is a transverse muffler.

Jim Hand

['ol Pinion head]

Can't get Flowmaster site to download....Anyone know what is the case length on the flowmaster 42852?

Anyone ever used the transverse Dynomax muffler #17276? This also is a dual inlet, dual outlet transverse mount muffler.

[Tom Hand]

Yep Larry, Rocky can give all the details about it; it was his muffler we used!
Tom

[455Dave]

OPH:

22 1/4 inches by tape measure; I have one in the garage. [img]/infopop/emoticons/icon_biggrin.gif[/img]

Jim:

I didn't really mean to say there were any hidden messages in your reply, but to reinforce that you have performed testing in a controlled environment where I was just swapping exhaust systems. There's a big difference between collecting observed data and scratching your head over the results of the last modification to the driveline.

Dave(I scratch my head a lot)

['ol Pinion head]

Thanks Dave!

[larry davis]

Mr. Hand, do you know the dimensions on those stainless Ultra-flow mufflers? I'm concerned about ground clearance.
Do they come in 3" inlet? [img]/infopop/emoticons/icon_biggrin.gif[/img]

[455Dave]

Larry:

17232 Ultra Flow Welded

Shell Diameter 4 1/2 x 9 3/4
OA Length 19
Shell Length 14

3 in 3 out Side/Side configuration

Can't find a 3/3 stainless model.

Dave

[Jim Hand]

Larry D.,
The Dynomax site has good information on all their mufflers, including photos and dimensions. Not sure of all available sizes but take a look at address below - then select "Muffler Applications (PDF)": Jim Hand
Dynomax

[ January 29, 2002: Message edited by: Jim Hand ]</p>

[larry davis]

Thanks Dave & Jim! [img]/infopop/emoticons/icon_biggrin.gif[/img]

[Larry Navarro]

okay...i bought a NEW transverse FLOWmaster muffler at a swapmeet for $15 bucks,(what a deal) anyway this unit has different inlet/outlet locations than the one in the complete flowmaster kit. it has the openings on either side of the case, like a factory muffler vs. the top inlet/side outlet from the kit. i installed this on my 73SD T/A last year. it sounds better than a stock muffler, but doesn't have the "drone", typical of the FLOWS.
are the flow characteristics between the two, the same? which one would be better?

[sscherin]

The Transverse muffler in the 17104 kit is the 42585 (Didn't know that, Thanks Rockey). The one Jim Hand tested in the 42582 muffler..

See this Picture from SUmmit of the 17104 kit

The 17104 kit's muffler has inlets in the side of the case. Not on the ends..

I'd be interested to see what the 17104 kit's 42585 muffler flows.. Anyone have a kit they haven't installed yet the Hands could borrow?

The 17149 kit has standard type mufflers.

I ran the full 17104 kit for about 6 years..
I've cut my pipes under the rear seats just before the rear hangers so I could drop out the front half at the track.. I used Stainless band clamps to put it back together for the street.

When I was running 13.05's I ran it open and through the mufflers with no real change in ET or MPH..

Current;y I rebuilt the removable section with a 3" Xpipe and flowmaster reducers to tie it into the rest of the system.. Works great..

With the H-pipe I had a loud drone at idle.
With the X thats gone and it's a but quieter at highway speeds (about 3000-3500 rpm with 3.73 gears).

Check Here for a pic of the X-pipe (home made)
Pics of the Front section wit X-Pipe
Poke around in here for other pics of the X.. Any pics starting with X
The rest of the pictures

[ January 30, 2002: Message edited by: sscherin ]

[ January 30, 2002: Message edited by: sscherin ]</p>

[455Dave]

That crossover looks good. I'd hate to think what it would look like if I made it.

I have one of the 17104 kit 42585 mufflers, inlets in the front of the muffler, not the side. It's available for testing although it is dingedup a bit.

Dave

[sherm455]

I would also be curious to what the 42585 would flow. It would be interesting to see the difference(if any) between the 42858 vs. 42582.