My factory exhaust has finally rotted away. Planning to go with a Dynomax cat-back, their P/N 17493 is the correct one for me, but their intermediate pipe is 2 1/2", and my stock pipe is 2 1/4". I know I've measured it right; why don't I have the 2 1/2" pipe? Did I just happen to get some oddball size here? Thanks in advance for any help here...

------------------
90 TBI 305 Formula
Original Owner
Auto Trans, T-Tops
Completely Stock Except:
--Flow Cooler water pump
--180 T-stat

 

Where is it 2 1/4 " ? At mufflere ? In the middle ? Near thge cat ? I have a 3 inch intermediate, but it tapers down to 2 1/2 at the muffler, and is 2 3/4 in the middle in some places too.

------------------
88 GTA 5.7 TPI Charcoal Grey Bone Stock except for loose muffler which makes it a bit louder than normal.

 

I though atleast a 2 1/2 inch but hey intermidiates are cheap and if you get the exhaust shop to mandrel one up it is better then the stock pipe as gm bent dinged and crunched in great place to make it fit for a nice cheap price. If you want lots o'power go with high-flow cat and the correct size pipe all the way back, or go with 3" all the way, which is stock for G92 TPI's and 5.7's.

My .0000002 of course that is if you have the cash to through at it otherwise go 2 1/2 inch all the way.

------------------
1989 Trans Am GTA, 5.7L TPI, TH700-R4, T-Tops, dual cats, 9-bolt rear, 3.27, Dynomax muffler, K&N
1992 Camaro RS, 5.0L TBI, T-5, T-Tops, 3.08, L69 Dual Snorkel, K&N - Sold

Theme song for my GTA Cake - The Distance

 

That's correct, but it'll fit anyway. Trust me.

 

The stock pipe on a TBI engine is 2.25". The aftermarket is 2.5" for better flow, and more power.

The better TPI cars have a 2.75" pipe, not 3". Altho I have had people claim their stock pipe is 3", I've never seen one.

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

Thanks for the input, people...I also talked to a tech rep at Walker, the ones that actually make Dynomax, at 800-594-9815. They assured me that their replacement intermediate pipe is 2 1/4" where it bolts to the converter but then is bumped up to 2 1/2" pipe size.

 

if you want a 3" pipe from dynomax I have the PN's in my sig.

------------------
-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz