Okay.... So it would seem that mine has had the thermostat mod and is SUPPOSED to be 161 degrees. Seems pretty cold to me, but I guess this is supposed to help performance. Just wondering because the car "feels" cold with how choppy it runs at times. As for the PCV thing, man!! Not really sure of the best way to address that issue, but the smoke in the cabin has got to go to be sure. This is too nice of a car not to have a better fix, so I'll keep researching a bit. My mechanic doesn't like catch cans either, so that kinda eliminates that I guess. I had an aftermarket system on it and thinking of having him put that back on at the risk of shoving oil down the intake for no reason. Sounds like that can cause a lot of carbon buildup over time. As for the car in general, it has started having problems with the transmission build (yeah, can you believe it after a $2000+ performance rebuild less than 1500 miles ago??) as it seems to be slipping. So, I'm taking it back to the tranny guy tomorrow to address that, then back to my mechanic to figure out the engine stuff. With any luck I'll have this car running well while I'm still young enough to enjoy it!! Thanks for all of the advice and if anyone has anything else to add, feel free. I'll update when the car is "fixed" again. Cheers...

 

Took the car back to my engine tuner and it still runs like crap in the morning, even though "cold" has only been 48 degrees or so. It still runs rough the rest of the time too. I'm told by others that this is a pretty bad "cam surge" and a poor tuning or may reflect a poor choice in the cam. My mileage average per the onboard computer is now down to 11.3mpg, driving the same way I did before my cam change getting anywhere from 22 to 28. The tuner did some tweaks, but otherwise made it sound like the car is "fine" and he "can't feel what I'm talking about". Trust me guys, something is definitely not right. Could some of you guys PLEASE CONFIRM what I'm thinking.... I've got a car with headers, cam, Texas Speed heads, 42lb injectors, DTE 3.73 gears, 2800 stall converter with fresh tranny, getting 409hp with 381 or 388 ft/lbs of torque, but it runs like crap when I'm just driving normally (putting around) like you would drive a Kia Rio and averaging 11.3mpg...... Is this normal and the best I can do? Could some of you guys share your setups and results on here for comparison.....? I really need to know where I'm at on this thing per my OP..... Was I expecting too much?? All inputs will we greatly appreciated. Merry Christmas......

 

Maybe the tuner did not adjust the tune with the correct values for the new injectors?

Take it to a different tuner, get a second opinion. Ask them if they think they can tune it better.

Probably cost you an extra $500, but it might just be worth it.

 

Injectors were not changed, just a new cam. I went to another guy who says he can tune it better, but the first guy "said" he could tune it too.... $500 later (yes, charged me full price for the tune even though it was a cam change and other repairs)..it runs like this. Not really sure who to trust on this now....

 

You said it had 42lb injectors, those aren't stock.

So you have had it tuned by 2 different tuners??

 

No, not stock....but present on the original build before changing my cam, so they were not changed out since I've had the car. The guy that did my cam/tuning was the original builder of this engine as well.... Just happened to find him when looking for a tuner after purchasing the car. As for the tuning, he is the only one to have tuned it so far. I'm just not sure about taking it to someone else since this guy told me he was a great tuner. I had another guy look at it who also says he is a great tuner.....but it seems EVERYONE boasts that....but how do you know for sure?? Do I just take it to him in trust and just not pay him if it doesn't run any better? He swears he can make it better... Plus, I already paid this other guy to tune it, so I kinda feel like he owes it to me to make it right or give me a refund on the tune... Of course, with the Holidays, everyone is out for the next couple of weeks anyway. Should I ask this other guy for a list of references or something? Also a little gunshy because I've heard that a really bad tune can kill these engines in short order.... Who to trust?!?!?! I just want someone that can make it right....

 

FYI - The onboard computer will not be correct once you change injectors. There is another table in the PCM that needs to be adjusted so the display can make up for the bigger injectors. BUT it will never be factory accurate again.

What size is the cam? 410 HP is a pretty decent number, depending on the cam your experience may be normal. A big cam in an LS1 can make the car a nightmare if it isn't tuned perfectly, especially when cold.

 

I don't have the specs on the cam. It's the builder's custom grind I think. I definitely "sounds" aggressive. The car already had a "tsunami" cam in it and this one sounds and feels nastier. I'm hoping it's not too over the top that it can't be tamed a bit more with tuning. Another tuner looked at the current tune on his computer and said he could make it run a lot better. I'm just a little skeptical and was figuring if it could have been tuned better, the original guy who built the engine should be able to do it....but, who knows? It seems every tuner claims to be an "expert" and has his share of both fans and naysayers. It sucks that you have to pay $500 and take your chances until you manage to find a good one who can dial-in your particular combo. I really just need to learn how to do this myself. I'm a pretty intelligent guy and it's not rocket science. Hell, HP Tuners even has a free repository of tuning files to try out.... Chances are I could find one with my exact combo....??

 

HOLY CRAP! I have a 02 ZO6. Stock, it had excellent power and if I drove it easy, it would get 30 Highway.

I added Stainless Works 1 3/4" primary and a 3" mid pipe and exhaust system, a VARARAM and ported Throttle Body. The car ran really rich before the tune and my fuel mileage was 25-26 highway and 12-13 city Highway. Had it professionally tuned and it dynoed at 390 RWHP 375 Tq. The tuner did a quick street data-log and some fine tuning. Power was very good but fuel efficiency wasn't that much better...

2004 Tuner in CT Dyno and tune session



Had a couple of other people try to tweak the tune to get the fuel mileage closer to the 30 that it use to get. Best I could muster up was 26-27 highway and 14-15 city highway....

A few years later, I installed some Patriot Stage II heads, home ported FAST 90 and home ported 90mm TB, 42 lb injectors and a ENGLANDGEEN Whiplash cam. The cam specs are 240 ish duration 610 lift at 114+4 Had a friend of mine use my EFI Live and wide band and help me tune the PCM. He changed the injector tables, did an auto VE tune, adjusted the PE tables and MAF, some timing table corrections a couple of days before I was to leave for Bowling Green KY for the cruise in. On the way down to Bowling Green, I was getting 26 MPG. ENGLANDGREEN (Stephen) said he would help me tune out a couple of little bugs that I had and we couldn't solve with the tune (Car stalled at IDLE when the AC was turned on.) Stephen did some Power Enrichment (PE) table changes to get my WOT PE Table AFR down some. We did the Back Street Dyno at Bowling Green after the tweaks and she pumped out 450 RWHP. On the trip back, I saw 27-28 MPG a couple of times with two people and a fully loaded trunk!

Bowling Green KY at the museum on the backstreet dyno 88 degrees @ 80% humidity.





So,,,,, YEP,,, your tune still SUCKS!

Find someone with EFI Live or HP Tuners and do some data logging. See what your LONG TERM Fuel Trims are doing when you part throttle cruising. If there significantly POSITIVE, while cruising around at part throttle you are NEVER going to see decent fuel mileage. To correct that issue, your going to need to use a wide band and have someone data-log and correct your VE tables and MAF tables and get that LTFT close to zero. Unless you have a wide band meter, your not going to be able to see what your PE table are doing at WOT.

When you change the injectors, your instant and average fuel mileage readings will no longer be accurate. EFI Live have tables that allow you to readjust those equations so there correct again. Make sure that you do the old fashion miles per gallon math checks to get an accurate reading.


Bill

 

SEE...... I'M NOT CRAZY!! I knew this was possible... I have similar mods to yours and getting only 409hp and my mileage and driveability SUCK!!! Does your car buck and misbehave or drive like the family sedan? I know it's possible to have both, but obviously my tune sucks. Anyone else that can share similar experiences that can give me some hope?? I would appreciate any and all...

 

Any time you have a cam with a bunch of overlap, the low rpm drive-ability suffers. My cam is fairly aggressive and it has fairly good low speed in traffic manners. No it will not lope along at 600 rpm in 6th like the stock cam.

My buddy and ENGLANDGREEN have it tuned so that its very drivable in traffic and it performs fantastic. I live with in 150 miles of Chuck at Corvettes of Westchester. I'm going to let him take a crack at it and see if he can milk a few extra HP out of it. He's got a new DYNO that will be up and running soon. Its time to do some more FAST 90 porting and tuning tweaks and see what that yields.

YES,, you can have a big cam and driveability. You just need to find the right tuner who knows his stuff and fine tunes the tables that matter the most on the street by data logging and street tuning. Dyno tuning has it place but, fine tuning with the car actually on the road, matters a LOT for fuel economy and low RPM driveability.

BC

 

Your tune is "OFF" - you need to have another tuner take a look at it !

Put it on the street and the on the Dyno for WOT runs!

The tuning needs to be smoothed out and the MPG issue can be solved you just need to get it over to an LS1/Performance expert - many HUGE cams can be smoothed out and what you are putting down should be more from your set-up! Especially MPG

If I missed it I am sorry - but what are you running as a tranny MN6 or A4? Rear gears, if A4 which are you running? Any Stall converter?

Thanks,Matt

 

Is this "tuner's" initials "JP"? If so, your tune is probably locked so that only he can gain entry.

 

100% with this statement

I have a 2000 Coupe LS6 N/A 6spd it is making 455rwhp 429rwtq the motor has 4500 miles on it and it runs like a raped ape and is Cali smogable minus the Headers (have a friend) it drives as smooth as it did when I bought it with a LS1 it gets 26-31mpg on the freakway. I would take it back and tell the guy fix it please. If that dont work find another tuner and open the wallet to fix it.

Pops

 

I think you still have a basic mechanical issue with this engine. Do a cylinder leakdown test on it, or get someone to do it for you. I'll bet a few cylinders are low. Good luck/

 

Time for a whole new engine. May not be worth putting anymore into that one

 

The specs on your cam are 238-242/605-610/113+4 Are you letting your car warm up or are you just starting it and going? Your tune can be spot on and the cold weather we've been having is still going to affect it some. I just had the same guy install a cam bigger then the T-Rex cam in my car and i couldn't be any happier with the results. The rest of the tuners in this area are a joke so i dont think you're going to get better results.

 

Yes, I'm letting the car warm up to at least 110 degrees before moving.... much more than you would wait to pull out with the family sedan. I should note as well that "cold" on a couple of mornings was nearly 60 degrees, but it didn't matter. In fact, the car isn't just limited to running poorly first thing when cold though. She still bucks and hesitates after warming up and driving to or from work.... 15 miles and longer. I'm not sure what's going on with her except to say that "she just ain't right!" As for the cam, it's cool that you have the specs on my cam Dibble... I've had several people ask, but I wasn't given the spec sheet for it, so I didn't know. As for the tuner, he really seems to be a good guy and good at what he does, so I'm giving him the opportunity to make the car right after the holidays. Maybe mine's just being particularly difficult or something else is actually wrong with the engine. He said he took the entire engine apart while he had it out and that everything looked fine though...so, who knows. Could even be a bad grind on the cam. In any case, I'm confident that if he spends the time on it, he can figure out what's going on. As for the tuner's initials or name, I've intentionally held that to protect his reputation until he's had another chance at making the car right. My main reason for this post was to make sure that my expectations for the car were reasonable and that I wasn't expecting the impossible. I suspected that my expectations were perfectly reasonable and now that I've had the inputs here, I'm sure of it. The car needs to go back and needs to be made "right"....and now, thanks to all of you, I know what "right" should be. Thanks to all for the great inputs and Merry Christmas.

 

Good Luck with it and the tuner thanks you for keepin it quite until the facts are known

 

I think I've got bigger issues than originally thought, but maybe not.. Found this under my oil fill cap.... Sorry I couldn't post the pic direct (had to post to my photobucket stuff), but please look and tell me what you think??

http://i552.photobucket.com/albums/j...ownload068.jpg