d0nkeypuncher08

I'm going to try and keep this as short and to the point as possible.

I bought an A&A kit and threw it on my stock 03 z06. Before I could even finish the tune on it, the stock motor popped on the dyno.

I put an HKE 403 iron block in it with the stock LS6 heads Stock LS6 cam, stock manifolds and the cats removed.

Ive been to the dyno multiple times, the first few we were addressing a fuel issue in where the tuner thought i needed a fuel pump. So i put the racetronix pump in with the harness and the boost a pump. Returned to the tuner with no avail still running out fuel. Then he said i needed fuel rails, well i thought i didnt and long story short it turns out that it was a fuel filter that was causing all the issues.

Ever since i got the car running with the 403 it has had a random misfire, but since the last time i went to the tuner we switched it to speed density and cannot read misfires anymore. He tuned it and on 11.81 psi it only made 540 to the wheels. A/F is solid getting plenty of fuel. He told me that looked pretty good and he thinks the stock manifolds are holding it back. I think its loosing a cylinder up top because i believe i should be seeing well into the 6xx rwhp numbers.

I just need someone around the Georgia/Florida area that knows what the hell they are doing to look at this thing and get it running right. Ive tried everything from spark plugs to cleaning around the orings for the injectors. Did a compression and leak down test on all cylinders and they checked out fine.

Current Setup:
HKE 403 stock ls6 heads stock ls6 cam
A&A vortech V3 SI trim kit 60lb injectors
Stock Manifolds
Cat Delete
Borla Axel back.
Racetronix pump and harness
KB boost a pump
Devils own Meth injection

547rwhp and 549 rwtq on 10.68psi

Corvette-Chris

The best shop in the states you mentioned is probably Vengeance Racing...At least it's the first one that comes to mind.

d0nkeypuncher08

Ive heard mixed things about them, but im going to give them a call and see about them looking at it.

Corvette-Chris

I understand. When you are local or somewhat local, you hear the good and the bad. Over the internet with supporting vendors and such, you only hear the good.

d0nkeypuncher08

A guy up there used to do the same job i do now so hopefully that will help

js23881

One thing thats killing you is lack of headers.......I don't see any in your set up detail. If you are running stock exhaust set up you are really chocking a blower set up.........I mean really chocking it....with 408 at least 1 3/4 should be used. I had a 402 set up with 13 boost on D1 and ran at rw 628 and rwt was 610. I added a 150 shot on that set up and was 0ver 770 and ran 9.70 many times....yesnod: Also just sld my set up and Vengence is building my LSX 440........Ron doers a good job...seen his shop and checked him out.

stevieturbo

But none of those suggestions will cause a random missfire.

If your tuner is continually recommending parts with no logic or common sense behind them, find a new tuner.

d0nkeypuncher08

Yeah I understand that i need longtubes...check. But people are continually making 580-620 on a stock 346ci ls6 with stock manifolds. Thats where I was drawing a blank. And right before the stock motor popped it was making 580. I'm going to give vengeance a call and see what they will do for me. I'm just tired of dishing out $600 here, $100 there, $300 there for tuning and the car still isnt right. Maybe i just learn how to tune myself

rclinton

I had a similar problem with running out of fuel with an LPE pump, racetronix harness and a BAP. It wasn't until I added a regulator on the stock 02 rail, and a return line back to the tank and swapping out the regulator/fuel filter with a 99 filter. Now running a constant 60 psi without the BAP. Kudos to ARUN for the info on the fuel system upgrade info.

stevieturbo

You dont need to buy anything other than someones expertise to fix the problems.

A guess that you needed a fuel pump is nonsense. You either need one based on factual testing or you dont.

I'd also say you didnt need fuel rails

And you dont need new manifolds to fix the problem. They are not causing a missfire.

It could be as simple as far too rich, a wiring problem, coil issue or wiring. A crank/cam sensor trigger/wiring issue. Or possibly some sort of mechanical/valvetrain issue.

An experienced and competent tuner should be able to make some sort of sensible diagnosis that your current one has been incapable of.

d0nkeypuncher08

I personally have checked/replaced. Crank position sensor, checked all grounds with multimeter meter(PCM ALSO), checked plug wires with multimeter, replaced spark plugs, switched spark plug heat ranges and plug gaps. Checked voltage to coil packs as well as grounds to coil packs. Checked all the valvesprings they are pac duals. I have pretty much been through the car over and over fixing things that the shop should have fixed when i had them put the motor in it because i didnt have the time nor the garage space to do at the time. Its frustrating as hell and I'm at the point where i want to drive it off a cliff or give it to someone decent and say fix it. The only thing i haven't done is swap coil packs. I checked all the pushrods as well. It was doing something strange and eating valve seals for some odd reason?

I dont want to seem like a guy who doesnt know what he is doing. I personally assembled and installed the 418 in my GTO and done tons of head cam setups. It was just my first step into the FI world and ever since that step it has been nothing but absolute problems.

It just really makes me mad when i trust a guy tuning my car and 6 pulls in a row he consistantly ran the car to 14:1 + AF attempting to fix the leaning issue. When all he had to do was take it up untill it started to lean out and stop.

Basically im about positive the original motor popped because of him, but i gave him the benefit of the doubt and its just got to the point now where im sick of it. But he has treated me well and hasnt overcharged me for all the times ive been down there past midnight on saturday trying to figure this thing out, i just feel his knowledge is lacking in a few areas.

Especially when this guy is a very well known name in LS tuning.

I was comming up with logical solutions and he was throwing parts at it..........

jbondfl

[QUOTE=d0nkeypuncher08;1579788597]Ever since i got the car running with the 403 it has had a random misfire, but since the last time i went to the tuner we switched it to speed density and cannot read misfires anymore.

Stock Manifolds

does your first post mean you don't HAVE misfires any more or just that you can't see them??

And I lurk here a lot (boost envy) and truly can't remember anyone posting up more than 500-525 on stock manifolds. Not only is that costing you HP but it is also causing confusion by pushing up your bost numbers artificially. Install longtubes and your HP will go up AND your boost # will go down///

Pekka_Perkeles

[QUOTE=jbondfl;1579794434]At least with HP Tuners, when you switch to Speed Density, PCM does not have the ability to follow or count random misfire anymore.

For stock manifolds, I had the same situation once with 427 and I think it was Kurt Urban who said to me that I'll only lose somewhere around 60 rwhp...which is of course a lot, but won't explaing any of the OP's problems..

d0nkeypuncher08

I believe it still has misfires, but instead of diagnosing the misfire issue before switching to speed density the tuner went to speed density, tuned it, called it all good even though i was down some 70 rwhp than where i should be. I have seen multiple stock LS6's on 10psi of boost hit at or near the 600rwhp mark without long tubes. Vengeance racing actually did one not to long ago. If you also check A&A's blog you will see quite a few there also.

It also doesn't idle properly, it idles like it has a misfire but i have no way of seeing them anymore or finding out which bank they are coming from anymore because its under speed density. It was tuned with EFI live custom OS.

I'm working on having the tuner send me all the log files he has so i can at least send them to a place and they can have a look at them before i drive hundreds of miles or spend another grand on tuning/diagnosing if its something i can just fix myself.

02402ramair

There are ways to determine if you have a misfire without misfire counts. You would need to look at the factory 02 sensors. If you have a cylinder go down during a WOT run you will see a lean 02 reading on that bank. If both 02 readings are not running neck and neck and following the same trend then there is your tell tell sign. A dead cylinder will show lean on that bank. If both 02s are within like 10% of each other during the run then you should be hitting on all cylinders.

d0nkeypuncher08

Forgot to add one thing, its also making peak power at 5200ish rpm..........

Peaks there and then falls off.

2bridges

I would focus on the issues and not get too hung up on the number.
From my experience the LS6 at 10psi with manifolds making 600RWHP is a stretch or at least an "optimistic" dyno

My low mile (<30K mile) LS6 on 9psi dynos 550rwhp WITH ARH headers, X and corsa catback. No way in hell a stock manifold LS6 at 10psi is going to make a 600 on this same dyno.



One thing that comes to mind:

What is the static CR of the iron shortblock?
Most boost builds have CR in the 8.0:1- 9.5:1 range, a fair bit lower than the stock LS6 10.5:1

Lower CR allows higher boost to be run, but will loose HP at the same given boost level with all factors being equal (timing,fueling,etc)


Good luck getting it sorted

HP_Addict

You got to find a good tuner. I use Lamar Walden Automotive located outside Atlanta. I would get a good recommendation from the forum and get several opinions. I suggest only listen to people who have actually worked with a shop and not second hand info or what someone read on the net.

You would have needed the rails anyway, so no loss there. Did you add a regulator and set it up as a return style fuel system? Once you get your bugs worked out, fuel might become an issue again.

Good Luck!

road pilot

Looking through this thread thinking..........
Are your injectors good and what do you have???
No long tubes major issue if you want big power.
What pulley are you running?? Smaller with tune
more boost and power.
Chaseing numbers so that you have bragging rights...
Big deal.
When your engine starts to run right tell everybody
you have 1000hp better yet rwhp.

d0nkeypuncher08

I could care less about what the numbers it puts up. I'm looking at the numbers seeing a problem.

Running a 3.6 pulley
Getting tubes soon
Has a racetronix pump, harness and a boost a pump. Stock rails. The fuel is fine now and we are in complete control of it.