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I read your post in the PD XS3 thread and replying here instead. Optimizing NA components is different than optimizing boost components. If you don't desire to spend significant money twice, I'd not spend more money until you've decided. If you add boost, then continue to insulate the engine bay as well as possible.
Dynos are merely tuning devices; if all you want is a graph that shows 500+RWHP, perhaps re-printing the dyno graph with smoothing set to 2 or 3 (but with spikes) will get you there. Your peak power curve looks normal for a LS3 intake manifold with its ~11" runner length, generally peaking near 6400RPM. With a different cam, you may get the curve to continue climbing after 5800RPM but still peak around 6400 and/or get it to peak a few 100 RPM later. An intake manifold with shorter runners will help increase power after 6500RPM but with power drop below peak torque.
I installed Rick Crawfords Rod Mod intake back in 2013 on my then 377ci LS3, smallish (per internet standards) cam and OEM milled (not ported) heads. My MAF table was perfect before the swap and afterwards I needed to increase fueling. My 4th gear pulls from 3400-6800 were .3s quicker. The next cam I'd like to try is the BTR LS3 S2 V2, with either AFR or TFS heads from Tony Mamo. Regarding boost capability, Rick Crawford posted elsewhere, "I have the intake on a 416 with a F1 pushing 23-24 lbs of boost....Definitely a lot stronger than a FAST. All the FAST manifolds that were on customers cars with 12+ psi had broken/split runner."
What primary OD are your Pfadt headers? If they are 1 3/4, then 1 7/8 would give you gains at upper RPMs with maybe a little HP loss in a small RPM range below peak TQ. I'm not a fan of 2"+ headers for my application.
On the street, I've found my LS3s have given the best acceleration with AFR near 12.5 2800-3200, ~12.1 3600-4800, 12.8 5200-5600, ~12.4 6000-6800. But my chassis is likely heavier (3400lbs plus occupants) than yours. I'm not enamored with E>10, as my fuel economy is already horrible
My car is a daily driver, I'm not sacrificing idle & parking lot behavior for a performance increase in RPM ranges I rarely use. My cable 92 TB plays nicer with my PCM than a 102. Here's a recent 92mm vs 102mm TB on 416 LS3 comparison (not mine): https://www.youtube.com/watch?v=uPdLbtIeJcs
If you decided to stay NA and budget isn't much of an issue, then I'd consider Mamo products with a new cam to avoid mismatch of induction parts.
Thank you for taking the time to respond, well, I'm not only wanting 500 hp by manipulating the graph. I would like an honest, solid 500+ horses to the wheel just to be in the club... sure I could compromise the tune, add a little more timing and leaning out a little more and possibly get it, but the tune would not be ideal. We kind of landed at a point where it's making the most it's going to make safely for daily driving. This is why I've been looking at potential intake manifold/Throttle Bodys but really having a hard time finding posted results of LS3 replacements consistently backing gains. Sure there were a couple, but for every one that shows a gain, 10 others show no gain at all.
The future is Boosted. Before I boost, I will add ported heads sometime next year. In about a year or two after that, I plan to add up to 10 pounds of boost and a fuel system to support it.
The cam I have will be there for a while... I literally just installed it... not in a hurry for a cam change to chase down NA 5hp. Heads will likely get me there. Boost will only magnify the NA power.
I've had my eyes on a set of TF 255's. I do a lot of business with Knowlton Thunder Racing and may let him at them when the time comes.
The PHADT headers I have installed are the 1-3/4 cat-less into a 3" x all the way back to exist. The entire exhaust from Headers to tail pipe is wrapped.
I'm sure they will do fine when it comes to adding boost.
Don't get me wrong, I'm happy with 495/453... and I'm also very aware of a DYNO being just a tool. So that 495 could be 485 one day and 505 another... what matters most is the actual tune and what the engine wants/needs and the numbers fall where they may.
So I haven't given it up, I understand the theory of operation and the benefits of smoothing entry points for airflow. I'm just sharing what I've been seeing both in the forms in all over YouTube. If there are a lot of people who've seen gains with the ported intakes then they are being out posted by folks who have done the ported LS3 intakes with little to no gains.
Thanks again for your response... I'm sure someone will benefit from the discussion.
Not a fan of the Pfadt Tri-Y headers. Especially with 1.75" primaries. My opinion is based on ownership of Pfadt headers and also other's opinions. I don't have any back to back tests with Tri-Y vs conventional 4 into 1 designs. I have no dog in the fight. Just relaying my experience and observations.
Pfadt used to boast of increased mid range torque/hp with their design. If you make the same hp at a lower rpm, torque increases vs the same amount of hp at a higher rpm. They never quite mention that peak hp is compromised to get that extra tq in the mid range. I think they'd be a lot more common if they were good throughout the rev range. My experience says they're not.
You don't do much racing at 3000 to 4500 rpm. They might have their place in some kind of road racing/endurance scenario where there is value in keeping the engine speeds lower to help with durability. I wouldn't have them in a street car, especially in the 1.75" size.
Conventional 4 into 1 1.875" primaries dumping into 3" mids with ZR1/Z06 spec mufflers would net you some power.
Not a fan of the Pfadt Tri-Y headers. Especially with 1.75" primaries. My opinion is based on ownership of Pfadt headers and also other's opinions. I don't have any back to back tests with Tri-Y vs conventional 4 into 1 designs. I have no dog in the fight. Just relaying my experience and observations.
Pfadt used to boast of increased mid range torque/hp with their design. If you make the same hp at a lower rpm, torque increases vs the same amount of hp at a higher rpm. They never quite mention that peak hp is compromised to get that extra tq in the mid range. I think they'd be a lot more common if they were good throughout the rev range. My experience says they're not.
You don't do much racing at 3000 to 4500 rpm. They might have their place in some kind of road racing/endurance scenario where there is value in keeping the engine speeds lower to help with durability. I wouldn't have them in a street car, especially in the 1.75" size.
Conventional 4 into 1 1.875" primaries dumping into 3" mids with ZR1/Z06 spec mufflers would net you some power.
THIS ^^^^^^^
That post above is right on point....even if you have a 1 3/4 four into 1 style header a move to 1 7/8 primary pipes in an ARH or Kooks set of headers would put you in the "club".
If the headers you have now are the Tri Y design you will see at least 10 more at the wheels as that design does in fact compromise peak numbers for some added strength in the middle of the range.
Or you can drive to a less stingy dyno down the street and get the number your looking for to stab the dyno sheet in the glove box.....LOL (alot less money....alot less effort!)
You might see 490 at the tire just as easily but the bottom line is a 1% difference is nothing and it can literally be the difference of a dyno run done at a lower coolant temp with the exact same tune on the same dyno (especially if the car was heat soaked on the 495 run)
Can you make more power legitimately....of course....but if your really just looking for a number is seems silly to spend thousands. If you want a bigger number and some real performance gains as well there are lots of things but its time and money
When your ready to step up your game my LS3 heads are the most efficient on the market.....390+ CFM thru a 260 cc port design is crushing it for an LS3 head (the same finished port volume as an unported stock LS3 intake that flows 315 CFM!!).
While the 390 CFM itself is very impressive its the airspeed this head offers that really sets it apart from my competition. Call me at some point and we can get into more detail at that time.
Some pics attached below....these heads work as good as they look
If you’re going to go boost in the future why do you care about 5whp on the Dyno?
The rod mod works. I picked up 9whp and 16wtq. I didn’t port my intake. The stock ls3 intake is tough to beat.
the tfs 255 heads suck with boost. The valves tulip. Leave your stock heads and stock manifold alone and throw on a centri.
The 1 3/4 headers are fine up 750-800whp. To much bro science on header size. The smaller is actually better for torque.
lol, I really don't care "that" much... I think some people are over reading into my point... it's like the commercial where the guy hangs a dollar bill on the end of a fishing line and yanks it away saying "ohh you almost had it"...
lol
I'm completely satisfied with the way the car performs as it sits... if there was an easy mod I could do to get over the 500 mark legitimately I would consider it... but I'm fairly sure I've already addressed most of the easy NA mods aside from the heads.
The PHADT headers seam to be doing well... most of the LS3s with similar mods are in the 480 range... that's what I was expecting... so the current combo seems to be working well...
Im leaning away from the intake idea, there really is not enough supporting evidence that the LS3 intake can be beat... equaled, sure but beat... it's a toss up from what I've seen.
That post above is right on point....even if you have a 1 3/4 four into 1 style header a move to 1 7/8 primary pipes in an ARH or Kooks set of headers would put you in the "club".
If the headers you have now are the Tri Y design you will see at least 10 more at the wheels as that design does in fact compromise peak numbers for some added strength in the middle of the range.
Or you can drive to a less stingy dyno down the street and get the number your looking for to stab the dyno sheet in the glove box.....LOL (alot less money....alot less effort!)
You might see 490 at the tire just as easily but the bottom line is a 1% difference is nothing and it can literally be the difference of a dyno run done at a lower coolant temp with the exact same tune on the same dyno (especially if the car was heat soaked on the 495 run)
Can you make more power legitimately....of course....but if your really just looking for a number is seems silly to spend thousands. If you want a bigger number and some real performance gains as well there are lots of things but its time and money
When your ready to step up your game my LS3 heads are the most efficient on the market.....390+ CFM thru a 260 cc port design is crushing it for an LS3 head (the same finished port volume as an unported stock LS3 intake that flows 315 CFM!!).
While the 390 CFM itself is very impressive its the airspeed this head offers that really sets it apart from my competition. Call me at some point and we can get into more detail at that time.
Some pics attached below....these heads work as good as they look
Cheers, Tony
im not that hell bent on 5hp to get into the 500 club... just shaking the tree to see if there's a small trick I missed that would get me over the line... I'm fairly sure there isn't. Since I do plan boost I don't really feel messing with the intake manifold is even necessary...
The PHADT headers do seem to be doing well with my current set up... I'm not going to swap headers for a hopeful 10HP gain... lol. They are installed for the long haul. I guess they will be the forever handicap.
Ill defiantly keep you in mind when I start shopping for heads... heck it may be sooner than later...
05-17-2024, 05:37 PM
