HP Increase Guestimate?
HP Increase Guestimate? I know it's one of those almost impossible things to guess at, but I was hoping someone could throw out some "safe" #'s for an exhaust upgrade.
My truck has 6.0 LQ9 (.030" over =370), milled 799 heads, Cometic .041" head gaskets, TSP 1 3/4 LT, 3" ORY pipe, .575"/.575" 220/224 @ 112LSA cam, and cold air intake, and a truck intake with DBC...
Exhaust from the Y pipe on back goes into a 2.5" single exhaust, then into a 2.5" IN/OUT Magnaflow.
The changes I'm making include cutting the end of the Y pipe off, and then going 3" pipes into a 3" X pipe, then dual 3" pipes out to 3" IN/OUT Flowmasters with turn downs in front of the axle. I'm "hoping" to get at least 10 more HP to the ground by doing this.
Is that reasonable to expect 10 more ponies to the ground?
My truck has 6.0 LQ9 (.030" over =370), milled 799 heads, Cometic .041" head gaskets, TSP 1 3/4 LT, 3" ORY pipe, .575"/.575" 220/224 @ 112LSA cam, and cold air intake, and a truck intake with DBC...
Exhaust from the Y pipe on back goes into a 2.5" single exhaust, then into a 2.5" IN/OUT Magnaflow.
The changes I'm making include cutting the end of the Y pipe off, and then going 3" pipes into a 3" X pipe, then dual 3" pipes out to 3" IN/OUT Flowmasters with turn downs in front of the axle. I'm "hoping" to get at least 10 more HP to the ground by doing this.
Is that reasonable to expect 10 more ponies to the ground?
TECH Junkie
Joined: Nov 2013
Posts: 3,913
Likes: 366
From: White Bear, Mn
I think it's reasonable. I felt a big difference especially in the upper rpms cutting the 2.5 in. outlet off my y and adding a 3in. Inlet to 4in. outlet then a 4in. electric cutout.
2.5in. outlet jams it up pretty good.
2.5in. outlet jams it up pretty good.
Just a quick update.. I got everything welded up, and installed. Truck is LOUDER at idle, but significantly quieter when going down the road. Without dynoing before, and after, I can't say for sure if I gained any horsepower. It feels like it accelerates a little quicker than before, but that may be just wishful thinking on my part. Can't say for sure. Just finished it last night so I have not put a lot of miles on it yet. I'm still getting that burnt aluminum paint smell after driving it. I know it will go away soon. Since it is a little quieter you can actually hear the motor better. The Magnaflow I took off gave the sound of a glass pack type muffler under heavy throttle and it drowned everything else out completely. Now I can hear the motor, and that nice throaty roar of Flowmasters. Anyway, that's my update.
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Verdad Gallardo Well, it's been a few days and I can say for sure the truck has a *little* more power than it did before. There is an intersection close to my house that once I pass through it, on the other side I could punch it before it upshifted into 2nd and it would spin just a little bit, hit 2nd and spin a little longer. This was a 20 MPH roll and hitting it right before it shifted into 2nd. I drive through this intersection every day going both directions to and from work. Now, it will break the tires loose in 1st, rev line into a 2nd gear upshift and carry the black stripes until it's just about to shift into 3rd gear.
Like I mentioned above, it is louder at idle, but quieter at anything above idle speeds. Not a bad trade off. I was stopped at a red light beside an HPD officer today and looked over at him and he was not paying any attention to me at all. He was playing with his computer, or cell phone, and he did not seem to notice my "loud" truck so I guess I'm okay there.. Now.... I am seriously thinking it's time for a turbo.. I am going to buy a book on turbo installation and make certain I understand what I am getting into with it.. So many people are doing it that there is no reason why I should not attempt the venture. I think a turbo is $$ better spent than wasting time trying to wring out more from a naturally aspirated set up. I've seen what FAST intakes run, and ported heads, and everything else.. Then I've watched guys put turbos on all stock 5.3L engines and make #'s that impressed the crap out of me... Can you guys think of any reason NOT to go turbo?
Like I mentioned above, it is louder at idle, but quieter at anything above idle speeds. Not a bad trade off. I was stopped at a red light beside an HPD officer today and looked over at him and he was not paying any attention to me at all. He was playing with his computer, or cell phone, and he did not seem to notice my "loud" truck so I guess I'm okay there.. Now.... I am seriously thinking it's time for a turbo.. I am going to buy a book on turbo installation and make certain I understand what I am getting into with it.. So many people are doing it that there is no reason why I should not attempt the venture. I think a turbo is $$ better spent than wasting time trying to wring out more from a naturally aspirated set up. I've seen what FAST intakes run, and ported heads, and everything else.. Then I've watched guys put turbos on all stock 5.3L engines and make #'s that impressed the crap out of me... Can you guys think of any reason NOT to go turbo?