after seeing the #'s break up like that at high RPM, I would adjhust the rockers again and make sure they are 1/8 to 1/16 past zero lash. Zero lash is the instant the rocker and valve have no slack. Most think zero lash is when you can not spin the pushrod or move rocker side to side, this is already too tight and tightening more than this will cause all kinds of problems. Some try and tighten them 1/2 turn or more and that is too much, even if starting from "actual zero lash" so if they are tightening this much after the pushrod doesn't spin, they are really gonna have problems.

The 1 5/8 headers and small collectors are NOT doing the HP #'s any favors and neither is a catalytic converter, especially a stock one with that kinda mileage.

Is there a cat back and/or cut out on the car or is the exhaust stock?

Replace the converter with a pipe and readjust the valves and then start tuning.

Here is a good example of a customer that started out with LE1 heads, LE1 cam, a stock TB, stock intake, 1 5/8 headers and made 350-360 RWHP #'s. After installing a bigger TB, better headers, better exhaust, more tuning, ported intake and Electric WP and then ended up with almost 400 RWHP with the SAME heads and cam. Just better complimentiong parts and more attention to detail.

http://web.camaross.com/forums/showt...ighlight=Lloyd

There are ALOT of ways to lose HP and only after getting all the right parts and getting EVERYTHING tuned correctly are you gonna get good results that compare to what others post up across the country.

Get the squigly lines out of the graph and you will be much happier but to get near 380 RWHP, you will probably need a bigger TB, 1 3/4 headers and good exhaust.

What CAI and TB do you have?

 

I made a few runs to get an idea of where the cam peaked
and found that initial estimates and tune were a little off.
I began cutting the VE table way too early and it caused me to run lean.
The results are on my cardomain site ( see sig ).
I chose not to start a results thread until I am done tuning.
(AFR, tranny fluid level, fuel filter, high stall, Edelcrap headers, etc.... I'm not sure what's causing the low numbers yet)
I should have track numbers this weekend (if I find a new DS loop to run with)

 

James, why do you have 315 listed (in your sig) as your torque when you put down 340? Also, the way your a/f drifts leaner and leaner, you may have issues with the fuel pump. My pump was running out of fuel up top on my runs and it was doing the same thing. Also, ask to start your pulls from 2500 or 3000 rpm instead of 4000. It makes for a better graph and gives you an idea of what kind of power you're making in your stall range.

What kind of timing are you running at WOT?

 

340 was a spike (likely the TC), the true peak was about 315.
I figured fuel pump or filter, I'm looking into that; but I'm also working on
fattening it up in the PCM. I think we trimmed it too much thinking i'd peak
lower. My injectors hit 80-82% DC above 6000rpm.

I didn't chose to start the pull at 4000, the dyno operator did.
He also chose to shut it down at ~6200 when I asked to run to 6400.
That dyno was expensive ($100/4pulls) and not exactly what I wanted,
but it was available at the time I wanted so I went for it.

I pick up 50 on my knock counter at that moment, less than .4* retard and it goes away within 500rpm. (This only happened on runs 1,2 and 4)
Run 3 did not pull any knock and shows similar results.

I was pulling 44* of timing advance to 3500-4000, then it drops suddenly to 36*
Exactly as the TC unlocks,locks and where TPS goes to 100% on each run.
This occurs on all 4 runs.

 

Just from my personal experience, I think the headers and CAT are your biggest problem. I had SLP Shorties and for a time I was running a stainless works dual cat y-pipe. If it were me I would get a really good set of mids with big primaries and get a high flow cat since you're in Cali. Also check and double check your lash, that is a very commonly overlooked problem. Finally I would look at the ignition and make sure that everything is good there cause that is a pretty common issue as well for our cars, not to mention H/C cars where the opti has been taken off and re-installed, sometimes incorrectly due to pin length as well as not being lined up correctly. You don't have a lot of mods so I wouldn't worry too much about your numbers, but you definitely have more room to grow if you get more complimenting parts.

 

RWHP #'s should peak at 6200 RPM with the LE1 cam and LE1/LE2 heads. It will probably only gain 5-10 HP from 5800-6200 RPM but it should peak at 6200 RPM and hang on until 6400 RPM.

Rocker adjustment, TB size, headers, exhaust and tuning can get in the way of it but the HEADS and CAM will peak at this RPM.

Lloyd

 

I appreciate you chiming in Lloyd. The rocker adjustment is at 1/16 lash. As for TB, its stock. Seems to be the consensus around here that it makes very little difference, but if you suggest I get one, I will. The most manifold vacuum I've seen is 1.5" at 6300rpms according to datamaster. The exhaust is the SLP 2OTL which I'm told flows well. My third run was with the cutout opened and it made no difference, so I think the catback works well.
I'll put a pipe in place of the cat today and in the coming weeks order up some long tubes which I should have done in the first place.

Todd

 

What size rockers do you have? 1.6?

 

Yes. 1.6 ProMags.

 

the stock TB is not hurting "that" much and I would start with getting the graph smoother up top, getting better headers and get the HP #"s peaking at the right RPM first.

Once all of this is done, you will see a 10-12 HP difference by going with the bigger TB but right now, there is just not as big of a strain on that stock TB the way it is runing and withj that exhaust so there would be very little gained by getting the bigger TB right now.

Lloyd

 

The cutout won't help ya if the shorties can't get the exhaust out of the head.

A hyd lifter adjusted to 1/2 turn will not hold the valve open unless it gets slack in the system at that valve,then it will pump up to take up the amount of slack that is there and hold the valve off the seat for a given amount of time??? until it pumps down. If ya adjust them to 1/16 then they can only pump up that much regardless of what the slack or pops the keeper out of the top. Well if ya got Comp "R"'s that's a different story. I have had some luck adjusting lifters with the engine running with a .001 feeler gage,then pull them to whatever ya want 1/16-1/4-1/2 running then ya know ya are at or damn close to "0" and the correct adjustment. Anywhere between 1/8 & and the factory 3/4 should do on stock lifters IF ya got the spring to do it.To much spring will not let them build up and take up the slack cause the valve spring is over riding the small check spring and not letting oil build up in the lifter. If ya shut it off and adjust them all, it probably wont crank 'cause all the valves are hung open. It takes OP and spring load to back um down.


What puts slack in the system?? Valve SPRINGS or severely flexing push rods. If ya keep a constant pressure on a hyd lifter with no slack it can't pump up on it's own unless it has a broken spring inside for the check or it has be fooled with. Trash in it will not let it pump up and they will clack at 1/2 turn past "0". If it can't pump up from trash or something else, ya could mash the plunger all the way into the body when adjusting(ya should see this with the adjustment nut) and BE bottomed out. Then when ya do the 1/8 turn your valves are hung open and they won't pump down 'cause there is no oil to move as oil is just passing through if it can't pump up from trash or something else. If it does pump up then look for P/V contact.
Ya have over .100 of travel in a lifter body so 1/2 turn is no where near bottomed out with the lifter at full pump up and on it's keeper.
Ya have to find .000 lash first to do this. I do a build and adjust with the intake off so I can see the cap move along with the "feel" method.

 

On my 383rwhp combo the difference between 5600 and 6000rpm was ~25rwhp.

 

I agree, on my setup from 5600 to 6300 it increased approx 30 rwhp. There is a lot of power to be had with this setup in the upper RPM range up to around 6300-6500.