Any Mod experts around
 

Hey everyone,

So I've been with my z/28 now for around 3 months and love it but wondering if I'm leaving any power left untapped on the motor N/A and if I should leave it alone as is.

Car was modded before I purchased so I dont necessarily have all the specs but they are as follow to the best of my knowledge.

lingenfelter GT-19 cam
lingenfelter aftermarket heads (potentially just ported stock heads? never could get a clear answer on this)
ARH headers catless with X-pipe
FAST 102 intake manifold with stock TB and intake

I recently had the car on the dyno and it made 556WHP.

I dont track the car and probably never will as I live in the cold hell that is northern Canada and strictly wanna use it as a street car

I have about the same set up white 2014 540 hp.SW Washington cold just put on 4 M/T only way to stop wheel spin ����

If you have the Fast intake a larger throttle body will help not sure how much HP it will make with your current setup but there’s several articles talking about larger throttle bodies helping power.

Number seems low for the Mods but all depends on what dyno as well. Does the car have bigger injectors? If not you might be running out of fuel. I would think that combo should be closer to the 600 mark. My car made safely made 575 on a dyno jet with AHP package 4 heads, BTR stage 3 cam, AHP 2" headers / no cats, and FID 700 injectors, stock intake and TB. I have a ported MSD and a NW 103 sitting hoping to crack 600.

I would say after the TB there is not much more to do without getting way deep into it.

That number isn't low...I've had 2 Z/28s, a '15 black and my current is a '14 red.
My current runs the same cam (GT19) and heads from LPE that you have, and I have kooks 1 7/8" long tubes, with no intake, and I have a soler ported TB (to help with the lag/drag on initial takeoff). Prior to the TB, mine dynoed at 545/489.4...the TB didn't add much of anything, but *maybe* puts it around 550 (but you really only feel the difference when taking off with some gas pedal applied). The FAST intake, which I had on my last Z/28, is probably giving you that extra 12whp. Personally I would advise AGAINST doing the 102mm TB. I did that with my last Z/28 and had issues getting a tune right where the car wouldn't stall at low RPM (read that as "backing out of the garage" RPMs) either going forward or backward. I had a tuner work around it, but every cold start was a "soot shoot" (my garage is STILL stained from it, 3 yrs later). I had multiple tuners tell me it was because of the 102mm TB I put on (and went on to say to stick with the stock, or maybe a ported stock, until around 600whp).
Now, whether or not thats true, and to be fair I have had a couple knowledgeable folks say it isn't, I had 3 different tuners not associated with each other who actually worked on my car tell me the same exact thing, at different times.

Wait, was there an actual question here, or are we just comparing things?

I might have the spec sheets for the LPE heads and GT19 cam still, I think I do....so if thats what you're looking for, I might be able to help :) I will say that I called LPE to find out if they used the bronze guides, and come to find out, they are using PM just like stock (a beefed up variation iirc, but still PM).