My LGM built 402 still on stock fuel pump (see sig)
on stock pump (z06) im at 612rwhp and no meth with some more still go once i open restrictor plate some on inlet of s/c
Sorry for the confusion, same sound different terminology
What's the difference between an ls1 and an ls6 fuel pump if anything ??
I mentioned ealier that my fuel pressure is dropping significantly under full load ( wot ) so the pump is tired/going bad or something. Anyways she does drive well as long as I keep my foot out of it and shift very early. Only issues are some surging and stalling. Also when the a/c is turned on the idle jumps to 3000 rpms. Not cool. Just a few examples of incomplete / bad tuning.
The Best V8 Stories One Small Block at Time
Get a programmer (hptuners or efi live), get a wideband O2 sensor, and start to data log what exactly is going on.
The days of me paying someone else to diagnose and fix my car are over. So LG screwed you this time, who was it before LG? I hope it's not VR after they do this build.
Knowledge is power, and when you put up all of these posts, it only hurts your knowledge base with everyone speculating on what's wrong with your setup. If you were able to data log your car, you could see what cycle duty your injectors are at, and what AFR you're running and not be worried about the sounds.
Please don't take this as a bash, but more as a helping hand. Do you know what your AFR is? How about your injector cycle duty? How about how much timing your seeing at WOT? Those are all critical peices to your puzzle that you are relying on others to tell you. Who's to say they will be honest. Maybe they'll tell you that you need a new fuel pump and injectors and fuel lines when you really don't, but unfortunately, you have no idea.
KNOWLEDGE IS POWER, how powerful are you?
Going to vengeance it sounds like you are changing the set up drastically which will compare nothing at all
https://ls1tech.com/forums/11674281-post44.html
Data was logged, fuel pressure drops quite a bit above 3800 rpms when throttle is open 100%. If you hold the throttle at an angle of just less then 1/2 the rpms will build safely without any strange noises that I have eluded too previously. Please don't take this as a smart *** response. Just make sure you read the posts before you tell me to do things that I've already done. My information will be checked and re verified once I go to Vengeance. As far as self tuning, not really interested. On the cost side, the sale fo my parts and the costs of the new parts were very "doable". More power for a small investment. BTW did you miss the part where Ron posted that he is giving me free street tuning, and free wot tuning on the dyno for the effort of coming to the shop from Michigan? Quite a nice gesture on his part.... Thanks again but all those bases had already been covered. Thats why I know its safe to drive on the bottom 1/2 of the tach. I shift at 3500 rpms now and keep in mind that its only temporary. Just glad its not hot yet, or I couldn't drive it at all. A/C on ='s 3000 rpm idle !!!
Going to vengeance it sounds like you are changing the set up drastically which will compare nothing at all
On the Vengeance swaps. The car will be baselined first and then individual swaps will be made so it will be a perfect real world a-b comparison. What are you smoking? Same day, same car, same dyno, what more could you ask for ??
To repeat myself, the car has been datalogged as far as Inj DC, fuel pressure etc. I am not going into anymore details. They will be released in a few weeks.
* As Doug said above, the diagnosis has been made.. Fuel pressure is dropping off above 3800rpm. This has been verified by a fuel pressure gauge off the rail and a GM Tech II Scan Tool. Doug and I have PMd quite a bit since he sent his car to LG and purchased our ported FAST manifold. Doug has had questions from time to time that he either didnt ask LG or they simply didnt answer. I have always tried to be helpful as anyone can see Doug is a true enthusiast and he loves his car and this forum... Doug described the issues he was having and I suggested he take his car to a local shop or a GM dealer and run a few diagnostics, which he did......
* A stock C5 pump in a 99 Corvette is NOT the same pump you will find in an 01 and up C5 Z06...Its obvious Doug is having fuel pressure issues at his current power levels. That being said, I have never seen or worked on this car. It all could be related to a simple clogged fuel filter and the car could have been perfect when it left LG.. I dont know yet. I do know we do not build 600HP combos on stock fuel pumps at Vengeance Im a bit surprised LG didnt want to atleast throw a Walbro 255 in the tank for insurance since Doug is so far away. Im not questioning their build Im just a bit surprised.
*I explained this before, but Ill do it again. When Doug aproached Vengeance about swapping heads on his combo I gave him a full quote and told him I would do the tuning for free. I did this because having paid LG for a complete tune I figured the car would be pretty close already and there wouldnt be alot of tuning required. I did not feel it was fair to charge him another 600.00 to make some minor tweaks if he was already happy with the way LG tuned the combo.
* As far as "useless comparisons" we have quite a week planned for Dougs combo when he comes in with quite a few A/B changes including:
Baseline customer vehicle upon delivery
Installation of Racetronix fuel pump/harness
Back on dyno/street for comparison of data logs
Remove LG 1 3/4 longtubes and install ARH 1 7/8 Longtubes.
Back to the dyno for A/B comparison
Remove AFR 205cc Cylinder Heads. Install TrickFlow 215cc Cylinder Heads
Back to the dyno for A/B comparison
Remove G6X3 camshaft
Install Vengeance custom camshaft
Back to dyno for A/B comparison
Complete Vengeance Tuning
This is ALOT more work than it needs to be, BUT we want to make the comparisons useful/valid/and most importantly imformative!!!! Doing things step by step should make for some useful information.
* In regard to tuning, FWIW, Doug will be driving his car while Mike is in the passenger comparment logging/tuning. Not only can Doug look at the logs/changes being made but he will also get a complete spreadsheet with the majority of the changes made in his PCM. We do not "lie" to our customers nor do we sell them stuff they dont need. We didnt build our reputation off of antics like that and we dont intend on changing.
I gotta get back to work.. I hope I cleared the air on atleast a few things. Remember, not every enthusiast likes to turn his own wrenches.. If he did there would be no speed shops
Fact is, you're still relying on everyone else to figure out what's wrong with you car.
It certainly sounds like Ron is going to help you out and take care of the issues. I've had nothing but limited positive interactions with Ron and am not bashing him or you at all. Just trying to help you help yourself, but I guess you're not interested.
EDIT: Ron I wasn't bashing you or Doug. I actually feel bad for Doug or any enthusist who gets treated like this. It's the reason why I try to be as informed as possible prior to any discussions so that I'm an educated consumer with as much data as possible. I guess that's just the scientist in me.
Best of luck Doug. Hopefully you'll be enjoying your car, more than half throttle and more than 3800 rpms.
Last edited by The Alchemist; Jun 2, 2009 at 12:56 PM. Reason: Just commenting.
Just thinking through this and theorizing, that's all.
RON ! Holy **** do you have a great ability to communicate in print. I unfortunately don't. thanks for stepping up and clearing a few issues.
Specifics will be shared after its all said and done. Please be patient.






