Thank you, and yes I realize it's a big issue. That is going to be the first thing I fix, then do a retune and go back to the dyno. What you're saying makes a lot of sense for sure. I just figured since air/fuels are fine it "should" be ok but I'm not seeing the whole picture I believe. I'm tossing in a DeatschWerks 340 and will still have my boost a pump installed, just wont be hooked up until I start using nitrous.


I will definitely do that!! I hover around 96-97 kpa at WOT, but I know I need a new air filter and will look into what your saying before I buy one. I only have so much area inside the little "box" that the filter sits in but maybe I need to switch to an over the radiator type.

Well that was my whole point... the adapter plates were only used on the Fast short runner intake. I ditched them when I went to the ported MSD and I saw literally zero gains. The fuel pump is next on the list as that's my Achilles heel at the moment lol. I'm going to retune after the new pump and go back to the dyno before switching out the cam, but that 252/262 cam is looking pretty good. I wont be spraying nitrous all but a couple times a year so I guess I dont need the exhaust duration any higher than 262 like I originally was thinking about with the BTR stroker nitrous cam.

Yes it's for sure tiny. I am running a boost a pump and have seen blown G8s get up around 575 with that setup so I figured with a leaner air fuel ratio I should be ok, but I know everyone's setup is different. The fuel pump is the next thing to go.

 

Ya, that is the MAP values I was at too. Went up to 99 kpa after making a new intake. I literally felt the difference on the street at WOT. Every little thing adds up!

Here's a quick guide to filter dimensions needed to support your engine. I had already created a spreadsheet and just updated it for 454 ci. Go ahead and save the image because I will delete it after a little while to keep my photos cleaned up.

Each curve represents a particular engine operating speed (rpm). The intersection of the x-axis and y-axis at the curves shows you the filter dimensions needed to hit the required surface area at that rpm. This will make it easier to shop for a filter that can fit inside your box. It assumes the filter tip diameter is 66% of the base diameter, which seems to be typical by my survey.

** link removed **

 

Might be smart to change the filter too. My 4th gen F-body filter had just 5K miles but I changed it and the pressure went up 5 psi at WOT (this is when my pump was still undersized).

That surprised me! But then I began looking at flow specs for my OE filter and realized it was one of the limiting factors too. I thought about buying an aftermarket filter but didn't when I saw how poor the filtration is compared to stock. This winter I'm probably going to plumb in 2 stock filters in parallel.

 

Are they the short travel lifters? What size pushrods are you running? I had an issue when I ran pushrods too long. Ultimately ended up with severe valvetrain instability, valve float, and the valves pulled through the retainers.

 

My lsx454 with cnc'd ls3 heads , fast intake , 1 7/8 headers, 102mm throttle body, the same cam 239/254 , fore innovations twin fuel pumps, made 540rwhp....
So pretty close if you compare

 

Ya I will definitely get a new air filter by looking at your graph - thanks for that! A new fuel filter is a good idea too. The 340 DeatschWerks will easily give me the volume I need, and the boost a pump will be a reserve for the nitrous at the track.
Pushrods were selected by the shop that built it, and LA motors is what they do. I didnt see valve float when I revved past 7k, and I've checked everything over and it's set for .30 preload which is what the Johnson lifters ask for. They are not the short travel, just slow bleed down.

That is definitely interesting. What was your torque? Do you have a graph by chance? I would love to see that for comparisons sake

 

This was before fast intake and 102mm TB . The torque was 595ftlbs and 526rwhp ... Think dynos here in Australia are like your mustang dyno there

 

That's pretty good power.
I'm only down 17rwkw but mine is a 408.
What rpm is your red line?

 

With the fast and 102 tb was 410rwkw....
6600rpm was near tops ...the torques where it's at... still had 675nm at tht

 

Damn that's good power.
Did you get those LS3 heads ported by Higgins?
I'm guessing the rpm would not have been high due to smallish camshaft size for that engine
But still it's a great result.

 

Re-read your whole thread. One question I never saw answered is your compression. It should be high on its own just from cubic inches, unless you have deep dished pistons. Not to be confused with deep dish chicago style pizza. Skipped breakfast...

Anyway, your power is peaking too low, and that's part of the reason for the low power number. RPM is power. Even getting the peak up in the 6500 range will improve your max power significantly. The cam you are running has too early IVC. Diet coke said it best. You may as well be running a 202 cam in a 346. On a 454, I would put your IVC out to 55 degrees. To get that to drive well, you'd want some compression. On the order of 12.5:1, which with a big cam like that will still run on 93. DCR will only be 8.4. So, if you run that 252/262 Bort threw out earlier, it's a decent match and will definitely run better than your current cam. Will have a ton of overlap, which you may or may not want to deal with. Kind of depends on your tolerance and intended use. You could run a 246/258-115+3 which will rev good and clean and be tame to drive. Would still want compression to make it work.

 

6600 rpm? Help me square up these numbers.

400 kw is about 535 hp
675 Nm is about 500 lb ft

535 = rpm * 500 / 5252
rpm = 5620 rpm

 

Thanks for posting. So we have the same displacement, same cam, I have better heads and at one point we had almost the same intake and you have 85 more ft lbs torque lol. That is about where I thought mine would be, maybe a bit less. Wow

 

The dyno's in the USA read about 10% higher than the ones in Australia.
I would say a dyno jet would be about 15% higher.
6600rpm is a bit low.
The OP definitely needs more camshaft.

 

I am the OP, what I'm saying is we have basically the same setup and I have 515rwtq and the other guy has 595 lol. If USA dynos read higher than it's even more laughable as we have the same cam and everything

 

I also forgot to mention compression.... I would go 12:1.1
The cam you specified would be more tame and having equal overlap on intake and exhaust it will drive good everywhere.
Then again the OP has a 3600rpm stall converter so he may as well use something bigger.
OP, I recommend this spec from Darth for something more mild at 22 degrees of overlap.
This will drive quite well in a 454 after a good tune of course.
The 252/262 113 LSA +4 will make more power and torque and has 9 degrees more overlap.
Will still drive ok with some good tuning.
All the good parts that you have and if it was mine, I would definitely go the bigger stick.
24 degrees of overlap in my 408 drove no different than 12 degrees.
31 degrees in a 454 I am betting will still be tame.
Get on to that fuel pump first!

 

Fix the fueling....you should never tune a car on dropping pressure. Regardless of the small cam, I would expect it to make more power.

 

Have you by any chance put a IR gun on the primaries to verify you do not have a dead or dying hole? During warm up especially. A cold primary will tell you a lot. Not necessarily due to compression either. Plugged injector or a bad spark plug or wire for example....

 

I will check temps today with the IR gun. I did a spark plug change literally minutes before my dyno session and they all looked identical. I've checked a couple after and same story but you could be right. I need to check everything at this point. I cant count how many of your posts I've read over the years lol, so I will check over all plugs, wires, and check individual temps today.

 

Good that you are checking the plugs. Makes a dead hole less likely but there really are not many good reasons for your torque to be down.