Before/After Dyno #'s on JDM/Kooks Full length headers
#1
Before/After Dyno #'s on JDM/Kooks Full length headers
Ok, First off, don't ever dyno one of these things with a hangover...much too loud. I won't be able to post the actual dyno graphs until monday (if anybody wants to see them)because I don't have a scanner. There was nothing done to the truck other than the JDM Full length exhaust system (full length headers, high flow cats, dual magnaflows). Here you go...
Both on street side program:
Before exhaust (Actual): 433.0 RWHP, 542.5 RWTQ
After exhaust (Actual): 441.6 RWHP, 563.6 RWTQ
Street side:
Before exhaust (STD): 420.5 RWHP, 530.7 RWTQ
After exhaust (STD): 431.9 RWHP, 551.2 RWTQ
You can see a gain of 8.6 HP, 21.1 Lb/ft TQ (Actual) and 11.4 HP and 20.5 lb/ft tq (Using standard correction)
Now for the Race Side program (All after exhaust)...
(Actual): 447.2 RWHP, 576.5 RWTQ
(Std): 436.3 RWHP, 562.5 RWTQ
Pretty good numbers I think. Now I just have to get that power to the ground (and it won't be by using ET Streets) See this thread for F1's vs. ET Streets dyno comparison.
Both on street side program:
Before exhaust (Actual): 433.0 RWHP, 542.5 RWTQ
After exhaust (Actual): 441.6 RWHP, 563.6 RWTQ
Street side:
Before exhaust (STD): 420.5 RWHP, 530.7 RWTQ
After exhaust (STD): 431.9 RWHP, 551.2 RWTQ
You can see a gain of 8.6 HP, 21.1 Lb/ft TQ (Actual) and 11.4 HP and 20.5 lb/ft tq (Using standard correction)
Now for the Race Side program (All after exhaust)...
(Actual): 447.2 RWHP, 576.5 RWTQ
(Std): 436.3 RWHP, 562.5 RWTQ
Pretty good numbers I think. Now I just have to get that power to the ground (and it won't be by using ET Streets) See this thread for F1's vs. ET Streets dyno comparison.
#2
What mods do you have, aside fom the exhaust? The numbers for more highly modified trucks are better with the LTs and cats added than with those closer to stock. 420 hp is a good place to start for this part to really pay off. Good gains.
I'd bet the gains are even better under the curve than the peak numbers.
I'd bet the gains are even better under the curve than the peak numbers.
#5
Originally posted by wkuper11
great numbers, I'm just curious, I am about to install my longtubes/cats this week, how much louder are they over stock headers/cats with a silver bullet?
great numbers, I'm just curious, I am about to install my longtubes/cats this week, how much louder are they over stock headers/cats with a silver bullet?
The Silver bullet requires some modification to match up with the JDM headers and midpipes. Mine was about 4-5 inches too long when fully assembled. The tips wouldn't exit through the cutout in the ground effects. I think it must have been designed, as a catback only, for the stock midpipes and manifolds.
#6
Mine was about 4-5 inches too long when fully assembled.
I'm going to order the cat-pipes on monday, i already have the headers, and the silver bullet is already on the truck, ill probably install everything on wed., I can't wait to hear it!
#7
What mods do you have, aside fom the exhaust?
I am about to install my longtubes/cats this week, how much louder are they over stock headers/cats with a silver bullet?
Definitely not for the 'faint of heart'. I set off car alarms regularly, just by driving by. I can't hear the blower whine at all.
Last edited by yysenhimer; 03-15-2003 at 07:39 PM.
Trending Topics
#9
#10
Originally posted by yysenhimer
See sig
I can just compare to stock exhaust. At idle, you can barely hear there is an exhaust, but when you get on it, everybody knows. I love the sound, it is real deep and doesn't drone when cruising.
Totally agree. I didn't have any problem with fit.
See sig
I can just compare to stock exhaust. At idle, you can barely hear there is an exhaust, but when you get on it, everybody knows. I love the sound, it is real deep and doesn't drone when cruising.
Totally agree. I didn't have any problem with fit.
I don't think you have the Silver bullet exhaust either. It is much more aggresive than stock at idle. The Silver Bullet has two cylindrical Magnapack mufflers as opposed to the dual oval shaped Magnaflows. The catback you received is designed specifically as a complete kit to go with the headers and mid-pipes from JDM. The Magnapacks are even louder. Maybe even too loud. Ouch.
what did you do just cut the ends of the catpipe where it connects to x-pipe? has JDM updated the catpipe to fix this?
I'm going to order the cat-pipes on monday, i already have the headers, and the silver bullet is already on the truck, ill probably install everything on wed., I can't wait to hear it!
I'm going to order the cat-pipes on monday, i already have the headers, and the silver bullet is already on the truck, ill probably install everything on wed., I can't wait to hear it!
#12
#14
Peak Hp changes are not very inpressive adding long tubes, but if you look at the results HALO had when they did same day dyno testing you will see they gained over 30 hp around 3500 rpm. I will go back when I have time and get you the link. Its on the HALO site (WWW.HALOCLUB.COM) message board. This is the only reason I bought the JDM kit. I sure as hell hope the twin Magnaflows (not the round mufflers)in the JDM kit are not too loud!
Jerry
Jerry