3" Downpipe gains with mild combo...worth it?

[richy rich]

Yes I too like the stock appearing look!
When I went the 11.94 alot of people came over and saw a stock GN with the fact wheels and stuff on it.
It was really neat!

 

[UNGN]

I tested the THDP vs. a 2.5" stock appearing downpipe elbow in 2001 at Buicks at Bristol. Combo was 3stoch long block, 36# injectors, TA49 with 275/60 BFGDR's, I ran about 6 passes with each downpipe. All passes were between 11.74 and 11.99. The difference between the averages between the DP's was .05 seconds and 1.5 mph, so the THDP seems to help on the big end of the track, and not so much with the first 1/8th mile.

Average mph went from 113 with the 2.5" DP to 114.5 with the THDP. All runs were through dual 2.5" ultrflow exhaust.

 

[richy rich]

I tested the THDP vs. a 2.5" stock appearing downpipe elbow in 2001 at Buicks at Bristol. Combo was 3stoch long block, 36# injectors, TA49 with 275/60 BFGDR's, I ran about 6 passes with each downpipe. All passes were between 11.74 and 11.99. The difference between the averages between the DP's was .05 seconds and 1.5 mph, so the THDP seems to help on the big end of the track, and not so much with the first 1/8th mile.

Average mph went from 113 with the 2.5" DP to 114.5 with the THDP. All runs were through dual 2.5" ultrflow exhaust.

That is some goood info!!

 

[bison]

I tested the THDP vs. a 2.5" stock appearing downpipe elbow in 2001 at Buicks at Bristol. Combo was 3stoch long block, 36# injectors, TA49 with 275/60 BFGDR's, I ran about 6 passes with each downpipe. All passes were between 11.74 and 11.99. The difference between the averages between the DP's was .05 seconds and 1.5 mph, so the THDP seems to help on the big end of the track, and not so much with the first 1/8th mile.

Average mph went from 113 with the 2.5" DP to 114.5 with the THDP. All runs were through dual 2.5" ultrflow exhaust.

Chances are your ex is/was a lot better than what most are running with similar mods and probably let you see more of the actual potential of the thdp. With less ex post dp id expect less than you saw. Good comparison.

 

[UNGN]

The small change in ET surprised me for the 1.5mph difference in speed. 1/8th mile Speed/ET were statistically the same, but the THDP must help above 4900 RPM, as there was an obvious difference in trap speed. The next time I went to the track, the same combo went 118.3 mph with better air at a lower altitude track. I don't think the Stock appearing 2.5" pipe/elbow was capable of that with that combo.