3 inch DP comparison

[87bigcut]

How much better is a THDP style 3 inch DP than one that comes off the stock elbow? OR compared to the Bowling Green one?
Anyone done any ET comparisons or dyno runs comparing the two, or even the seat-of-the-pants dyno?

thanks,
Joe

 

[Tony87gn]

From what I understand the THDP is like the king of the downpipes, it's at least the most popular I have seen. I have not seen the Bowling Green one so I don't know.

 

[Red Regal T]

Bowling Green unit isn't available new. It employs an oversized cast iron elbo and sure is ugly. Get a THDP.

 

[madhat]

Why not ATR, around here, that's what most of the GN guys use...don't get the stock elbow one, they still use the stock elbow for one, and they are softer and the flanges will bend on you.

 

[Geoff87]

This is a post from UNGN a while back. I'm running a ported elbow/3" Kirban Downpipe I bought off this board a while ago, because it was cheap. If I had to do it again, I'd get a Terry Houston DP and be done with it.

Originally posted by UNGN
The difference was actually only .055 seconds and 1.5 mph with the 1/8th mile et and mph being very similar. 5 runs with each throwing out the worst two.

Ported elbow/2.5" ATR downpipe/testpipe:

11.840 @ 113.08
11.859 @ 114.66
11.836 @ 114.72

Average:

11.845 @ 114.15 (avg 60 ft 1.680)


Terry houston 3" DP/Capped dump pipe:

11.745 @ 115.36
11.788 @ 116.05
11.838 @ 115.62

Average:

11.790 @ 115.67 (avg 60 ft 1.687)

Difference = .055 seconds and 1.52 mph.

This was with a TA49 and using 28 inch tires/lockup converter.

With a larger exhaust wheel turbo or a combo set up for Higher RPMs (26 In tall tires/non lockup converter) a TH style downpipe would help more.

On a more stock combo, I'd imagine it wouldn't help as much.

 

[87bigcut]

thanks for the good info

Joe