74u

iTrader: (9)

Also, I should mention there was over 0.3" ptv clearance mocked with clay. I'm sure the lifter collapse exaggerated the measurement, but I doubt there has been any contact.

Pray

iTrader: (7)

Martin, that makes perfect sense to me that it was designed for a 402. I am sure it runs like a stocker in a 416. It is funny how close to the cam we came up with for my TBSS this one is if you just look at the advertised numbers. But looking at the valve events tells a completely different story.

I have used a few sets of TFS heads with YT UL's in the past. I set them up on a table to get the correct wipe pattern on the valve stem. All of them needed to be shimmed up about .090" give or take some to get the correct valve train geometry. That by default extended my pushrod length by about the same. I am almost positive that I had to run 7.650" push rods since the TFS heads usually ship with 7.550"s. I would think that if they are too short now that you are loosing lift and duration if the lifters are now essentially acting as solids. You will loose what ever lift is being consumed by the travel before contact. If they are too long then you hang valves and loose power. Since you built this motor I would go back and double check. What rockers are you running and how did you set them up? Still not a smoking gun. However, we may only be looking for 15-20rw once the exhaust is fine tuned. That can be little things at that point.

Sales@Tick

iTrader: (3)

Along with the compression test verifying zero lash length on the push rods is another good idea.

slowride

iTrader: (3)

Now I know in most cases a 3" exhaust doesn't rob that much power (especially on a 5.7 NA car), but I had a FD RX7 I put my old cnc 243 heads and a cam I cut on a stock 5.7 ls1 GTO bottom end. This thing went 415-420 whp 385 wtq and I was super confused. Nice swap headers and straight shot intake, ls6 manifold, ported tb, 6 speed cobra IRS, etc. We ended up Dropping the Apexi "Dunk" style muffler (3.25"-3") and it went right up to 455/406 after a couple pulls and afr tweaks. Nuts how much power the exhaust was robbing. I know Borla exhausts tend to use straight through mufflers, but the f body one has a one in two out approach and might have a little too much back pressure in this case.

74u

iTrader: (9)

I will be upgrading injectors soon so I can use my dry kit...when I do I'll be doing a back to back pull with the headers open vs. through the cat back. I don't expect anything amazing, but since it such an easy/free test why not rule it out.

I think Martin has right though, if the exhaust were the choke point it should still make great torque down low and the real power loss wouldn't begin until higher up the rpm band.

slowride

iTrader: (3)

You would think, but in my case the exhaust was ~ 20. This is all same day/dyno stuff. We had done multiple pulls at the lower power and the first pull without the rear exhaust things just jumped everywhere.

Pray

iTrader: (7)

I would agree with the exhaust statement if your fuel was dialed in on the graph. Let's take a closer look at your dyno graph. It takes 1,000 rpm for the fuel to dip below 13.0 afr from the hit of the throttle at 2,800. No fuel, no torque. By 3,800 though you are already at 440rwtq. I would have to look at some other graphs but that seems pretty good to me considering your rear gears. Most TQ peaks on these motors is around 4,800-5,200 rpm. Then your fuel goes rich to 12.2 afr or so and you are dead in the water on TQ. It stays flat or drops off from there so with HP deing a mathmatical derivitive of TQ you can't have the first with out the latter. So your tq climb is essentially done by 3,800 where an exhaust restriction could be taking over at that rpm and TQ level along with being too rich. I haven't seen any gains from going richer then 12.6 or so at peak TQ. I usually only go to 12.7-8ish then back up from there if there is anything to gain. Each dyno WB is different though. I am sure your tuner knows his dyno.

Pray

iTrader: (7)

Don't know if this will pop up but at 3,800 I was only making 460rwtq and by 4,800 I was making 530rwtq.

http://i311.photobucket.com/albums/k...16Compdyno.jpg

Pray

iTrader: (7)

Here is another issue that I believe is a large one more than others do. You are sitting at only 8.22 DCR with your current 11.2 SCR and your IVC of 50.5. 12.0 SCR would put you at 8.78 DCR which in my opinion would produce a bunch more torque. N/A motors need compression. That has been my experience at least.

Sales@Tick

iTrader: (3)

The main things I would look at is what changed from the 402 with stock casting heads and 244/248 cam to the 416 with 225 heads and 239/246 cam.

Process of elimination.

I agree that more area in the exhaust piping would open things up. I agree that a 1.75" primary is a bit too small for a 416, even in a lower RPM street car.

That said, those two things just don't add up to not making torque on the bottom end. Cylinder pressure is not being made for some reason.

74u

iTrader: (9)

Reused parts from 404...(made 471hp @ 6200 w/valve float past 6200 due to heavy roller rockers ---- 10.84:1 scr)

Intake
throttle body
Headers/full exhaust system
injectors
MAF
Crank
Rods
engine covers
sensors
all electronics/ignition parts

Not reused...
Patriot III 243's --- SOLD
TSP custom grind 244/248 -- 617/619 with 1.8 rockers -- SOLD
Comp Pro Mag 1.8 rockers -- SOLD
LS2 Block 4.010 bore -- SOLD
Diamond pistons -- SOLD
pushrods 7.400 x 0.080 -- SOLD
Valve Cover Spacers -- SOLD
LS2 Timing Chain/gears -- tossed
Unknown clutch - tossed
OEM fuel pump - tossed

New parts installed w/416 build...

New L92 block (pistons fitted to bore 4.070)
New Wiseco pistons, pins, ring pack (lighter than the pistons used in the 404 despite being 0.060" larger
New Tick Cam
New 7.550 x 0.080 pushrods
Rebuilt stock rockers w/trunion kit
New TEA TFS 225's w/PAC springs
New LS2 Chain/gears
New LS7 clutch/flywheel
New Racetronix 255 w/hotwire

1989GTA

Again I say do your exhaust test on the dyno and see what happens.

slow trap

iTrader: (22)

yes,both are slight restrictions,but changing both out will pick him up probably between 15-25 rwhp tops,which he would still be be quite a bit shy of what it should be making. that combo should be 500+ rwhp and 480-500 rwtq imo.something just doesn't add up. finding the culprit may be something simple or may take a while. i hope you find your missing hp op,chasing problems and having to keep throwing money at these things is no fun.

74u

iTrader: (9)

Using the calculator on Wallace's site and trying to figure out what my cranking pressure should be with my combo...I don't know this information "Inlet Valve Closes ABDC :__________in degrees".

I'll be doing that test in the very near future. Engine is probably going to have to be cold, or just slightly warm at most in order for me to get my hands where they need to be.

Pray

iTrader: (7)

Your IVC is 50.5*. You may have to add 25 to that number to get the accurate cranking compression. You have to do that on the DCR calculator.

Sam88Gta1

iTrader: (13)

The WB on the dyno is a little lazy reacting with this cars exhaust. It usually is with a Borla cat back.
Rich or lean in either direction + or - a full point will not gain or lose 10 rwhp or tq. 20* of timing and a 11:1 a/f ratio would still make 440rwhp 430rwtq. 28* and a 13:1 a/f wouldn't make more than 460rwhp 445rwtq.

74u

iTrader: (9)

Hi Sam-

So you were in the same room for dyno tuning. You tuned/drove the car and gave it a pretty good once over while it was strapped. I know this isn't what you were hired to do, but I would love to hear your impression of the car and any suggestions you may have.

Do you think it's possible that the car is running on seven, or valve(s) hanging open from pushrod length, or exhibited any symptoms of a hurt motor, assembly defect? Pull no punches

All headers are hot...and since you tuned it I have gotten great gas mileage, steady 825rpm idle, and really no sign of a inefficient broken motor. My next step is compression testing. Then what? Where is my torque & horsepower?

I went to RedLine the same evening we dyno'd and made two nearly identical passes exactly as you saw the car.

92mph with some quick pedaling required on the 1/2 shift...I feel there may be 2-3 more mph in it with better traction/air...way below where I hoped to be, and unfortunately not even where I was with my old combo that floated valves.

Pray

iTrader: (7)

As I stated in my previous posts refering to tuning, I am sure you know your WB and dyno and tried a bunch of stuff to get the best results you could. I know the little issues with the dyno and WB of the dyno I use and how it all needs to be lined up or set up to work. I was simply trying to add value to the post analyzing what information was posted. In my experience with tuning on the dyno I use there is more to be gained than 10rw by tuning. If that was all we were going to gain with a difference of 2 points of AFR and 8* of timing then why would we do it.

Since you are basically the only person trying to help here that has actually laid hands on the car what is your opinion on what is going on. I think we all agree that the numbers are not adding up on the dyno or the track. I think you input would really help the situation here.

1989GTA

Pushrods do seem a little long. I believe stock is 7.4". The EPS camshaft going in my new 427 short block specifies 7.425". Maybe it is just a bunch of things adding up with out a magic bullet so to speak.

DEFYANT

Those numbers seem awfully low to me. A lot of us on here have saw that out of H/C/I M6 10 Bolt LS1 cars. I would expect at least 500rwhp out of that, on anything but a Mustang Dyno.