NufNuffZ28

iTrader: (13)

Well, 1st background on the car. Mods and dyno #'s before the cam as follows

1999 SS M6 with 4:10 gears and 315 rear tires and 115k miles on it.

Lid with K&N
home ported TB
LS6 intake
ASP pulley
!EGR
!AIR
SLP long tubes with random tech cats(pretty much hollow)
Borla catback with open plate
hardened pushrods
~with the above I made 346/360


add

F13
PRC dual springs
ported oil pump
Comp cams timing chain


New dyno numbers CORRECTED are 362/360


total timing was 26 and A/F was OK, but not too far off(ie high 13's)

Aborted runs as knew tuning wouldn't get me too much more and that something else may be amiss.

Cam off a tooth is pretty much out of the question as we turned it over several times and checked it. Also peaks were at the right spot(HP around 6100) Torque peaked around 5k, and charts weren't rough or anything either.

Also replaced in the last 3k were fuel filter, plugs, and wires.

Car runs smooth(as much as a cam car can) so I wouldn't think a plug or something was dropped on reinstall, but wouldnt a misfire or ignition show up as a choppy graph?


Thanks for ANY and ALL help



Chris

Bo White

iTrader: (59)

The new fuel filter may be faulty and causing fuel delivery problems, maybe why your lean. This shouldnt account for the 20+ hp your missing though Have ya checked for proper PR length, may need another size to get the geometry right. I feel its probably a couple of small things amiss somewere.

NufNuffZ28

iTrader: (13)

Well sorry, the FF has been on BEFORE the install so it shouldn't be an issue. The pushrods are stock length 7.4 what Futral recommended. Thanks for the reply man!!

Rick@Synergy

iTrader: (5)

did you even check the preload on the lifters with those length pushrods?

Now I am confused, did you say you were tuning or the car is not tuned? When I hear high 13's on AFR, I think you are not tuning....or for the sake fo the tuner, I hope he was not tuning also.

Rick

NufNuffZ28

iTrader: (13)

Sorry, started tuning, but saw how low and thought something may be amiss with the engine itself so aborted tuning.(which sucks cause now Im out $60 for the three runs I did!! )

Did NOT check preload on the lifters. They were already in the car from a previous bent stocker a year or so ago.

They are stock 7.40(hardened Comp cams and what Futral recomended. After the swap we simply pushed the lifters back down(via the pushrods) and torqued the rocker arms to spec. What do you think could be amiss as far as checking preload on the lifters?


Thanks Rick!!



Chris

NufNuffZ28

iTrader: (13)

Oh yeah, I also have the .hpi file from this run if anyone is interested.


Thanks


Chris

SideStep

Yes, I would like to see it. Please email to shamrockx@comcast"dot"net

Just replace "dot" with a "."

Rick@Synergy

iTrader: (5)

just because lifters were already in there, does not mean you cant check preload anytime later.

IF you thought there was nothing out of the car left and the air fuel was that high, I dont think you let the motor even do what it was supposed too at that point.

Rick

BLK02WS6

iTrader: (2)

Was the car tuned at all? I would recommend a complete wideband tune - not just a quick and dirty dyno tune, but a complete tune from top to bottom with a wideband. You would be amazed at how much difference a proper tune will make.

86 IROC

iTrader: (14)

A local guy w/ an 01' Z28 M6 running the F13 made weak #'s like you. They chased it all over... ended up being bad knock sensors. It was weird because the car didn't throw a code or detonate. But his #'s jumped considerably after they replaced the sensors.

If you know someone w/ a similar car that will let you swap around parts, you might be able to track it down w/o buying anything until you know for sure what it is.

Also, I see you have a K&N. Check the MAF to see if the wires in the MAF are dirty from the filter oil.

Hopefully you can track it down fairly easy.

Adrian87GN

iTrader: (5)

Maybe I missed something but untuned 360 rwhp sounds about right, and a gain with tuning should land you in the 385rwhp range, no?

SPANKY LS1

iTrader: (24)

Exactly, that cam would benefit GREATLY from tuning. With those headers, cats, and lack of tuning, I'd think 362 is pretty good actually. Tuning could give you 10-15 rwhp, which is where you should be IMO. Those headers and cats are hurting you some too. Tune it fully (by a good, experienced LS1 tuner) and see where you're at before you get concerned.

Good luck with it, Shawn

TroubledWine3

iTrader: (3)

What's wrong with SLP headers, performance-wise? Sure they don't fit that well and they give you bad clearance but I was unaware that they had a flow problem.

Ryan02SS

iTrader: (3)

Add a tune for sure and see where you stand. Check all loose ends on the setup to make sure everything checks out allright. A 115K mile shortblock will not throw down the same power numbers a low mileage 20K shortblock will.

Stangkilr

iTrader: (47)

388rwhp w/o a tune here. His #"s are low for an fm13. I hope you find out whats wrong.

SuperZ

iTrader: (2)

Mine dynoed similair with simimlair cam before tune back when it was cam only.I would fully tune it and see where you get.380s would not be bad not everyones car can dyno 400plus cam only.

NufNuffZ28

iTrader: (13)

Thanks for the tips yall. Yeah 380's would be OK,high milage, 4:10's and 315's I guess. Tomorrow I'm checking the plugs/wires, etc and some other small stuff to see if anything is found out of the ordinary.

NufNuffZ28

iTrader: (13)

Oh yeah, Shamrock you have mail.


Rick, with the low numbers it was pulled off as I was afraid something else may be wrong with the car, thats all. So in a way Im asking for advice of general things that could be wrong with the car on reinstallation.

Appreciate all the help guys!

HectorLS1

iTrader: (6)

Change the lifters, and tuned her. You should see a significant jump.

Slowhawk

iTrader: (12)

A/F of high 13's is not really ok for a stock headed car.That would explain only 26 degree's of timing.
380hp is normal for a Cam like that with the right timing -A/F which your car did not have on the dyno.

You should go back and rent the dyno for an hour or so and start playing with the tune.