98Z28CobraKiller

iTrader: (17)

Was injector duty cycle checked? Are you running the stock fuel pump? When I first put my setup together I had 60# inj with a stock pump. Inj Duty Cycle was at 110% and I had very similar numbers as you. Changed the pump and picked up the 40 RWHP and 35 RWTQ that I was missing.

RGKSR

iTrader: (9)

I'm sure it was checked, but I'll ask. I'll also inquire about the timing.

A fuel pump would be an easy fix. I'm running the LS7 injectors (39 lbs) that come on the L76 intake.

The car is a blast to drive, the tune is very good. My neighbor came over to tell me how good it sounded yesterday. I offered him the keys, but he can't drive a stick. What a shame!!!!

Bob K.

the_merv

iTrader: (88)

^^ You are more trusting than I am..I won't let anyone drive my Car after it gets done..

WKMCD

iTrader: (2)

I let one vette friend drive my car once. He got in it and revved the pi$$ out of it like it was a 346. I had to show him how to "enjoy" a high torque stroker.

98Z28CobraKiller

iTrader: (17)

Yeah, double check that. Is it the stock pump in there now? If so, it MUST be replaced with a higher flowing unit. I use the racetronixs plug-n-play. Just because the dyno is not showing it leaning out does not mean that you are flowing the correct amount of fuel.

2c5s

iTrader: (11)

I may have missed the year of his car, but it sounds like a c5. I've seen 540+rwhp out of the stock fuel system, I'm not saying it's the way to run, but, I don't think it's a fuel pump issue unless it's just crap'n out completey. A fuel pressure gauge will tell the story with one WOT run...

NEVRLIFT

I agree. The C5 and C6 really don't have fuel system issues until going into some seriously high power.

Max@Cartek

Here's the graph:



Max

RGKSR

iTrader: (9)

Here's the flow numbers for the L92 heads.

Intake
.100 .200 .300 .400 .500 .600 .700
77.63 155.25 226.91 277.96 323.81 346.30 357.54

Exhaust
.100 .200 .300 .400 .500 .600 .700
76.26 133.46 171.59 200.19 219.25 225.61 228.79

Max,
Thanks for posting the dynograph!

Bob K.

White_Hawk

iTrader: (3)

I don't know if anyone else sees it, but that curve goes a little flat at 5900 until about 6400. It doesn't look like valve float, though. Still, I think there is an anomaly there.

-Geoff

2c5s

iTrader: (11)

Looks like a stout 346".

RGKSR

iTrader: (9)

I spoke with the guys at Cartek today and I'm getting a new cam. I should have it installed in about 2-3 weeks. I think it's very similar to what Kevin (WKMCD) has. I left it up to them to pick one for me.

I asked them to spec something out last week. I gave them my wish list for the new cam. I was not happy with my results (460/420) with my existing cam.

I'm very interested in seeing what the numbers are on the Dyno. If this cam is half as good as my new Cartek clutch, I'll be thrilled.

Bob K.

RGKSR

iTrader: (9)

I stopped by Cartek this morning and picked up my new cam. Thanks Dave!!

It's 235/239 .597/.604. I have a Vette show this weekend or I'd have it in by tommorow afternoon.

I think that I'm gonna by a happy camper after the tune.

Bob K.

WKMCD

iTrader: (2)

Bob, I think you'll be MUCH happier with that cam. I'll bet I see your smile all the way down here in Virginia.

Patrick G

iTrader: (14)

So you're going to pull out your 235/248 .646/.615 114LSA +2 advance and put in a 235/239 .597/.604 cam? What are you expecting the new cam to do for you that the old cam couldn't?

I predict that if you gain anything, it will be from additional tuning and not from better valve event. Too many people on this board and the Corvette Forum have made big power with cams in the range of your original cam. Most of them are also running 1 7/8" headers and 32-34 degrees of timing too. Are you?

RGKSR

iTrader: (9)

Patrick,

Do you think it was the tune?

I don't think that the 1 7/8 headers are doing to give me 40 RWHP. I do not know what the timing is. I left that up to Cartek.

Let me install the new cam and get it tuned and the numbers will speak for themselves.

Maybe I will get more, maybe I'll get less.

Bob K.

edcmat-l1

iTrader: (10)

Dont be so defensive Pat. We cant all be right all the time (except me of course )

HHHMMM.... Good case for a controlled experiment.

Patrick G

iTrader: (14)

It's not the case of being defensive, it's the case of a combination not being optimized before a change is made. Talk to any of the board sponsors (like LG, Synergy and HTM) who have had strong success with L92s and you will find consensus in 3 areas:

1. The L92s are much more sensitive to overlap and where it occurs. They make the best power with a later intake valve closing point, a later intake valve opening point, an earlier exhaust valve opening point and the same exhaust valve closing point that works best in an LS1. What you come up with are cams with overlap that is around 15 degrees at .050", wider LSAs (like 114-116), and larger splits to the exhaust.

2. For whatever reason, the L92s like about 4 degrees more timing than cathedral port motors. That means if you're not running 30-34 degrees of timing, you're leaving power on the table.

3. 1 7/8" headers have shown bigger gains on the L92 motors than cathedral port motors. Anyone running an 1 3/4" header could be leaving LOTS of power on the table.

I would expect that the timing was not optimized, the compression was lower than expected and the smaller headers were holding the project back. By addressing any of these 3 points, you could look like a hero without even touching the cam. Like I said, Cartek is smart enough to find missing power in the tune. How much credit they give to that verses the new hardware will probably never be known.

edcmat-l1

iTrader: (10)

Sheesh^^^ Just razzin ya man.
I realize there may be more in other areas.
And without starting any wars, I know of more than one L92 package from a "board sponsor" that dont run right, and (one) is probably over cammed, not to mention some pretty shoddy tuning (same car).

Stang's Bane

iTrader: (22)

Just to play devils advocate here.

Did anything change from when you spec'd the cam to installation?