ok, gmhtp mag is doing a story on a '89 formula they quoted the dynomax super turbo cat-back as being $167 plus s+h
is thiscorrect, b/c that sounds pretty cheap for a cat -back.
they also said it added 12 hp and 10 ft/lb of tq (close estimate)
now i know this was on a tpi vehicle, so my gains would be diff, but i thought cat-backs were more expensive

 

yeah catbacks are not that much....

270 and under..

i thought dynomax only had the dual kit for the thirdgen's i was looking on Jegs and i saw about the same price for a 89 formula...

 

I`ve got one on mine and I have been very pleased with it that price quote sound about right to me.

 

I am pretty sure that cat back system is a 2.5 inch system. And the muffler that comes with it is not the best flowing one they have. But it is a good system for a stock or mild 305 probably.

Do a search for DYNOMAX PART NUMBERS. There is a thread on here with the part numbers to make a 3 in. cat back from dynomax. It adds up to over $300. That gives you the larger pipes and an awesome muffler that is capable of 427 hp without loss through the muffler. Not that you would need that much flow but you never know. I just put the 3 inch. muffler on my car and it as quite as can be at idle and sounds awesome at full throttle. It looks like a straight through muffler with no sharp turns or anything but has dual exits.

 

Actually the system they are using in that magazine is a 3" system designed for dual cat cars. And I do beleive that price is right, dynomax is one of the cheaper catbacks but also one of the best flowing.

 

Yep, the one I have for my 88 IROC is 3". The first muffler went bad (rattling), but they replaced it no problem (lifetime warranty on the muffler). Very smooth and prompt customer service - that's a big plus to me.

I like the sound too, it's not as loud as other cat-backs (which was my goal), but it has a nice deep tone - not like the flowmaster "boat" sound.

 

So you guys are saying Dynomax has a 3" cat back for $167. Give up the part # and location to buy please. Cause I cannot find it and the 3" intermediate pipe and 3" pipe over the axle come close to that price at summit. That leaves the muffler and tailpipes to buy. Here are the part numbers summit has that where posted by Gunny Highway but it adds up to more than $167:

Int. Pipe - 44063 - $83
Pipe over axle - 43248 - $49
Super Turbo Muffler - 17740 - $64
Tail Pipes
Inner - 43252 - $35
Outer - 43253 - $32


Thanks!

 

Jegs part number 289 17495. their details link doesn't work, but this place has the same part: http://www.quicktimeperformance.com/3gexhaust.htm

have fun!

 

oh, the two tail pipes are 2.5" but the intermediate from the cat back to the muffler is 3" ...

EDIT: okay, Summit is saying it's a 2.5" system - i'm thinking typo? maybe they meant 2.5 rear exit pipes .. i could swear that intermediate pipe is larger than 2.5" ... i'll check it out tomorrow while i'm working on the car ... just to make sure!

 

I thoroughly researched this over a year ago.

The only opposite side tail pipe exit Dynomax “cat-back” system they have available now (specifically for 3rd gens) is actually a 2.5" mandrel bent pipe with the 3" flange connector for the converter. Dynomax does make a true 3" mandrel pipe system with two 2.25" pipes exiting the drivers side,,, I think it’s about $200 from Summit.

As stated you can get the true 3" pipe separately as 2 part numbers – intermediate pipe #44063 (with the 3" converter flange) and the "over the axle" 3" pipe #43248 - and you could run what ever muffler you want. I went with the Race Series Dyno max #17227 - 3" inlet with two 2.5" opposite exit tail pipes. Dynomax claims this muffler flows 940cfm,, but it's $100. You can also buy the 2.5" tail pipes from Dynomax as part numbers 43243(RH) and 43244(LH) from Summit. It looks like with current pricing that would run close to $300 though. I thought about going with a single inlet/outlet Borla, but decided to go for the “stock look”. I really like the way it performs and sounds - different than most of the 3rd gens running the dreaded cross-flow Flowmaster

You can go to www.dynomax.com and download their complete catalog.

 

yep, my bad ... i measured it and it's 2.5" I.D. pipe ... damn ... ah well ... i'll be looking for a 4" soon anyway

sorry - i do know that dynomax does make a 3", but do not have the source or pn for it right now, but i'll be lookin!