Dyno Results

Scuba-Matt

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Who's your tuner? Your numbers look a bit low, Stick a #2 lower on her and you'll pick up half of that HP you lost. The JLP Comp R exhaust is probably hurting you more than helping you. 3" exhaust is a bit big for stock heads and cams.
I would think you can safely run 16 PSI boost as long as the tune is spot on and you run 110 octane.
I ran 18 PSI for 2 years on a stock bottom end. 1 year with the KB 2.3 and 1 with the Whipple 2.3, Its All in the Tune
 

99SnakeBit

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Well first lets talk about your tune, what timing are you running? what a/f ? Your numbers are weak IMHO for what you have. Hell your setup is pretty much = to what im running other than the lower pulley. Im using a 4lb lower on mine and seeing ( I think ) about 14-15 lbs of boost. My numbers are off of a mustang dyno too so.... Im betting like Matt said, that 3 inch exhaust is harming you rather than helping.

I run my 4lb lower on my truck and I have NO worries at ALL about my motor going boom. For too reasons, 1st my tune is safe and I have a a/f ratio thats just a hair rich and I know thats costing me extra hp I could have but Im running the fat tune ( for extra insurance ), and my timing is mild also. 2nd weather you guys believe it or not I dont beat on my truck AT ALL. I drive it casual with next to never wot blasts. Hell I dont go over 3 or 4 lbs of boost:sleeping: boaring I know but thats just the way it is :p I think you can run at least a 2lb lower and you will be fine, hell you can probally run a 4lb and be ok, as long as you have a good tune that has a set of safety boundaries.
 

DjKush

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Yea agree, put a 2# and ull be fine. To the post above, makes a lot of sense with the exhaust being to big, learned sumthing new today :]. anywho, IMO go all out, and go built hehe
 

Jeff_Svt22

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Modular Depot near cincinnati,OH has always tuned the truck. They do a really good job. I dont know if you remember beef cake with the silver L or not, but they done all his tuning and still do for that matter. but anyway i'll eventually throw the 2#er on and see how it does. Id like to atleast get back up to 13-14psi. I probably wont be going to the track any this year to see how it runs since its already turning pretty cold here. hell with these numbers id be lucky to break into the 12's anyway
 

RMoore92

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Pretty much same point as the above post about the 3inch exhaust. Its breathing to well one it comes off the heads but its bottle necked in your heads. I run a 6#er and a 3.375 whipple upper and only make 15 psi because of all the porting and bigger valves in my heads. I saw you ran a 4#er and a 3.50 upper and made 18 and was shocked until i saw you were on a stock motor. Your blower is doing the work to make the power not so much the motor.

Its all about the air flow and matching up all your hardware to work together.
 

Jeff_Svt22

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So what would be my best bet to make some decent power on this stock bottom end? Although im pretty sure i will eventually go built somewhere down the road, it just wont be anytime soon.
Just swap pullies and be done with it until i go built? ditch the JLP exhaust (man that was hard to even type) :eek:?
 

99SnakeBit

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So what would be my best bet to make some decent power on this stock bottom end? Although im pretty sure i will eventually go built somewhere down the road, it just wont be anytime soon.
Just swap pullies and be done with it until i go built? ditch the JLP exhaust (man that was hard to even type) :eek:?

Ok dont get pissed for me asking this but that exhaust cost you like 2 grand right :shrug: why didnt you put that toward a built block if you intend on going that way eventually anyway?

I would think to put at least a 2lb back on if not a 4lb to get you back up to your previous numbers ( or at least try too ). Im going built too and Ive been told I was dumb for getting this whipple put on FIRST like Ive done :bored: but I dont care, I wanted it so I got it. Im guessing thats the case with you and your exhaust :beer:
 

Jeff_Svt22

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Ok dont get pissed for me asking this but that exhaust cost you like 2 grand right :shrug: why didnt you put that toward a built block if you intend on going that way eventually anyway?

I would think to put at least a 2lb back on if not a 4lb to get you back up to your previous numbers ( or at least try too ). Im going built too and Ive been told I was dumb for getting this whipple put on FIRST like Ive done :bored: but I dont care, I wanted it so I got it. Im guessing thats the case with you and your exhaust :beer:

hell it would take alot more than that to get me pissed lol..but yeah thats pretty much the case, i wanted it so i got it. See I wanted a new exhaust system (headers and all) and the only one that I REALLY like the sound of is the JLP exhaust and I knew that whenever i DO go built wether its tomorrow or 10 years down the road, this is the exhaust thats going to be the best for what im wanting later on. so i just didnt see a point in buying a cheap exhaust that i didnt really like for the time being and just end up changing it later on down the road when i go built.
I see your point and what your saying makes alot of sense, but Im just not to the point where i want a built motor just yet, but hey when i get to that point im pretty much going to have everything I need to put down some decent numbers.
 

2003svtf150

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I'm squeezing 398/494 @ 12psi with a stock block, eaton, 3# lower and dynatech LTs/mids

Sounds like you're getting the shaft somewhere by only making 412/461.

How large are the Dyntech LTs & mids? I don't think they're 3 inch... and 3 inch can be too large for a truck. Just because you bolt on something better doesn't mean the motor can make something out of it at a lower power level.

--Matt
 

Jarrett H

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for a STOCK headed/camed one yea 3 inch is overkill

Please show me the graphs of the same truck in the same conditions that makes more power with a 2.5" over a 3". And I for one, don't like having to buy a second exhaust because people spread rumors that dual 3" is too much for a blown v8.
 

Scuba-Matt

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Please show me the graphs of the same truck in the same conditions that makes more power with a 2.5" over a 3". And I for one, don't like having to buy a second exhaust because people spread rumors that dual 3" is too much for a blown v8.

The proof is in the first post, The engine exhaust has to have a certain amount of scavenging. The 3" pipes and bigger tube headers on the comp R are over kill for stock heads and cams. there isn't enough air being pushed out to produce the proper amount of scavenging.
Don't get me wrong I love the 3" Comp R exhaust and will be putting it on my L soon. And if the OP is going built, then the exhaust is one thing he doesn't have to worry about down the road.
 

Jarrett H

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I'll make this short, there is no "proof" in the first post. It's quite amazing how you have absolutely attributed the his exhaust to have low power which could be a million different things if in fact he did even have low power. It is extremely common for people that run NA v8's to run dual 3" and still make more power while sacrificing some torque.

We although are talking about a supercharged v8. The main difference between this an a NA v8 is the combustion chamber pressures and the extra exhaust gasses that are expelled as compared to a NA engine. We are also talking about a truck that is making any where from 500-600 hp depending on the boost he is running.

To the OP, your numbers look slightly low for the boost your at but not anything I would call home about.Many things come to play when trying to decide how a truck might dyno less than another. Ambient dyno room temperature, humidity, cylinder compression, the dyno you are on, slipping transmission, timing, HEAT SOAK, and many other factors.




The proof is in the first post, The engine exhaust has to have a certain amount of scavenging. The 3" pipes and bigger tube headers on the comp R are over kill for stock heads and cams. there isn't enough air being pushed out to produce the proper amount of scavenging.
Don't get me wrong I love the 3" Comp R exhaust and will be putting it on my L soon. And if the OP is going built, then the exhaust is one thing he doesn't have to worry about down the road.
 
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Scuba-Matt

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I'll make this short, there is no "proof" in the first post. It's quite amazing how you have absolutely attributed the his exhaust to have low power which could be a million different things if in fact he did even have low power. It is extremely common for people that run NA v8's to run dual 3" and still make more power while sacrificing some torque.

We although are talking about a supercharged v8. The main difference between this an a NA v8 is the combustion chamber pressures and the extra exhaust gasses that are expelled as compared to a NA engine. We are also talking about a truck that is making any where from 500-600 hp depending on the boost he is running.

To the OP, your numbers look slightly low for the boost your at but not anything I would call home about.Many things come to play when trying to decide how a truck might dyno less than another. Ambient dyno room temperature, humidity, cylinder compression, the dyno you are on, slipping transmission, timing, HEAT SOAK, and many other factors.

I'll Make this short. I've seen this in to many instances to just jump to conclusion's. So believe what you want.
Anyway Sorry you got your shorts are in a bunch over this.
 

99SnakeBit

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ooooooooooo K let us know how the pulley swap goes if you do it. Good luck
 

Sinister04L

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Please show me the graphs of the same truck in the same conditions that makes more power with a 2.5" over a 3". And I for one, don't like having to buy a second exhaust because people spread rumors that dual 3" is too much for a blown v8.

I got my built engine from a guy who had it in his truck for 2 months before a business opportunity came up and he needed to sell his truck. I swapped my stock engine for his built one. He was running the Comp R exhaust system with no cats. I was running Kooks LT's, highflow cats, and a Bassani BX catback. We both ran the same pulley configuration (8# lower, 3.25 upper), he had no cats, I had highflows, and he ran 12* timing, I ran 10* timing. The same engine, on the same dyno, tuned by the same tuner. He made 613/670, I made 614/674. So with the same boost, but him with no cats and more timing, the numbers were almost identical. The Comp R system gave him nothing over my set up, and might have even cost him a little bit. This is on a built engine/ported heads/cams combo. If it's not going to pick up anything there, running it on a stock engine certainly won't pick up anything. That's my 2 cents.

Jeff, there's no point in even running a Whipple if you're only going to spin it to 11psi. They really pick up once you start spinning them and get them into their efficiency range. With a 2# lower and 3.25 upper I made 501/582 on pump gas. You don't have to be that aggressive since you don't want to risk blowing your engine, but you don't have to turn it down that much.
 

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