TVS 1900 / LS3 makes NO POWER!!

[Hambone!]

Hi everyone, have one of those "Perpetual Projects" that always seems a week away but never gets completed. While the history of this build is fraught with delays, missing items, dis-interested customer service reps, incompetent dealership "Master Techs" and weather, it all boils down to this.. I have an L92 with the VVT removed and replaced with a Comp blower cam. I don't have the specs with me, can get them if it makes a big difference. Patriot dual-springs, long tube headers and a TVS 1900 are the rest of the engine combo. Trans is a 4L80E, rear is 3:73 with 265/75/16 rubber. It is a 4WD vehicle, running on the dyno (2wd) it only made 316 HP / 342 LB FT. Boost comes right up to 6, occasionally to 7. But it feels slower than with the last engine. There's no urgency, no snap, just a mild pull in the upper register. Magnacharger says its the tune, tuner thinks its a mech problem. Compression is good, varies from 175 to 210, with 210 being the anomaly. All the other cyls are 175, 179, 185, 180, etc. Pretty close to each other. How can ANY V8 with 6 pounds on it be such a slug? A bone stock Tahoe with the L92 makes 322 to 377 at the wheels. Anyone had this issue? Suggestions?? Thanks, would be nice to finish this thing. Has been since APRIL! That's 6 (SIX) months of being jerked around.

[tooblue]

Post the dyno sheet if you are able. Also are you getting any engine knock ?

[Bmf5150]

Weird problem

[Hambone!]

Post the dyno sheet if you are able. Also are you getting any engine knock ?

Waiting to receive it in an e-mail. Curve was pretty flat, just super low. Hopefully will have it to post today.

[CarlC]

What does the timing look like?

[Hambone!]

AF is 12-1, Timing is 15deg. from talking to the tuner, still waiting on the sheets / logs though.

[Nessumsar]

First off, I know very little about boosted tuning; but 15* sounds very low, IIRC ~20-25 is where you usaully tune a FI engine?

[tooblue]

What Cam is installed (Specs). Was this done with convertor locked? Hopefully Trans is not slipping? What gears and how tall are the tires? Has the Tuner performed tuning on supercharged vehicles in the past?

[anthonys 69]

are you still running a catalytic converter if so you should remove one of the o2 sensors the one before the cat and check exhaust back pressure with a pressure gauge. you should not have more than 1 to 1.5 psi at 2000 rpm if you have more it can kill your power. good luck

[anthonys 69]

Timing and boost can be tricky I’m putting together a supercharged sbc. I’m going to run a crank trigger set at 30 degrees. Low compression motor around 8.2-1 so starting wont be a problem and my msd box will take out 1deg of timing for every lb of boost. So 10 lbs of boost 20 deg max timing. So your timing might be a little on the safe side but better safe than sorry. Good luck

[Hambone!]

Well I finally have the HPT file, but not the dyno sheet. Of course, I have nothing at the moment that can READ the HPT file, but I can send it if anyone wants to have a look. I am waiting to see the dyno sheet with RPM / AFR info.... waiting..... dammit.

[Hambone!]

are you still running a catalytic converter if so you should remove one of the o2 sensors the one before the cat and check exhaust back pressure with a pressure gauge. you should not have more than 1 to 1.5 psi at 2000 rpm if you have more it can kill your power. good luck

I put 2 new Magnaflow bullet style cats on it (3").

[Hambone!]

What Cam is installed (Specs). Was this done with convertor locked? Hopefully Trans is not slipping? What gears and how tall are the tires? Has the Tuner performed tuning on supercharged vehicles in the past?

Cam is from Comp, but purchased through a Frederick shop that kind of screwed me over. I should've gone with a sponsor.....next time I will. Anyhow, Adv Dur is 277/285 @.050 227/235 LSA 114 Lift 613/620 It was my mistake to believe the shop, I thought I was paying for expertise, not advice. Comp tells me its not ideal for what I have, but they still expect to see at least high 400's at the wheels. And I'm making less than a STOCK motor at the wheels. Sooooo next step?

[tooblue]

Well I finally have the HPT file, but not the dyno sheet. Of course, I have nothing at the moment that can READ the HPT file, but I can send it if anyone wants to have a look. I am waiting to see the dyno sheet with RPM / AFR info.... waiting..... dammit.

Can u attach the file to your thread? I have HPT and should be able to read the file.. If not send it in a PM if that works better..

[SicMonte]

Cam is from Comp, but purchased through a Frederick shop that kind of screwed me over. I should've gone with a sponsor.....next time I will. Anyhow, Adv Dur is 277/285 @.050 227/235 LSA 114 Lift 613/620 It was my mistake to believe the shop, I thought I was paying for expertise, not advice. Comp tells me its not ideal for what I have, but they still expect to see at least high 400's at the wheels. And I'm making less than a STOCK motor at the wheels. Sooooo next step?

wow...so comp said the cam was wrong but our "favorite lil speed shop" said it was ok? That's a smack in the face....but we are both getting quite used to that aren't we?? If you want you can email it to me and we can look at the charts tonight on my iphone. Im pretty sure it can open any kind of file.

[Hambone!]

wow...so comp said the cam was wrong but our "favorite lil speed shop" said it was ok? That's a smack in the face....but we are both getting quite used to that aren't we?? If you want you can email it to me and we can look at the charts tonight on my iphone. Im pretty sure it can open any kind of file.

More like a punch in the d i c k. I found out the cam they sold me was actually from another customer's build. Was for a Trailblazer SS project and it must've been left on the shelf. Yay. How do you attach files to here anyhow? I'll just mail it to anyone that wants to see.

[Hambone!]

Can u attach the file to your thread? I have HPT and should be able to read the file.. If not send it in a PM if that works better..

Well another wrinkle....I can see the file the tuner sent is 472KB, I can see it ends in .hpt, but it won't download. Keeps saying server is not responding. File coming soon......stay "tuned". Ha, that's not funny, I'm sorry. I hate this project now.

[Mike Norris]

If you want e-mail the file to me at [email protected] and I will see what it has. It would also be nice to see a data log during the dyno run which would end with .hpl if at all possible.

As far as the cam, it may not be perfect for what you have, but it takes a big screwup on specs for an LS engine to be missing that much power. I generally use a 224/236 114 in any SC'd LS3 and in M6 cars get 575-625 RWHP at 9-10 PSI.

I am still thinking cam timing may be off.

Let me know on the tune and hopefully the log.

Mike Norris

[Hambone!]

If you want e-mail the file to me at [email protected] and I will see what it has. It would also be nice to see a data log during the dyno run which would end with .hpl if at all possible.

As far as the cam, it may not be perfect for what you have, but it takes a big screwup on specs for an LS engine to be missing that much power. I generally use a 224/236 114 in any SC'd LS3 and in M6 cars get 575-625 RWHP at 9-10 PSI.

I am still thinking cam timing may be off.

Let me know on the tune and hopefully the log.

Mike Norris

Tune sent. Thx.

[Mike Norris]

I got the tune and have a few concerns for sure. I am going to reply in the e-mail and I would really like to see an HP Tuner log of the best dyno run as well as a look at the dyno sheet with air/fuel reading.

One other thing I forgot to mention is about the 4L80E in that it will show about 35-40 HP less at the tires then a 4L65E. Not saying that this thing should not do 450+ at the tires even with a 4L80E, just saying. And on top of that if you have a less efficient converter that will not hold with the lockup commanded on, there could be another 25 or so HP loss at the tires.

What brand converter do you have and what stall??

Mike Norris

[SicMonte]

I got the tune and have a few concerns for sure. I am going to reply in the e-mail and I would really like to see an HP Tuner log of the best dyno run as well as a look at the dyno sheet with air/fuel reading.

One other thing I forgot to mention is about the 4L80E in that it will show about 35-40 HP less at the tires then a 4L65E. Not saying that this thing should not do 450+ at the tires even with a 4L80E, just saying. And on top of that if you have a less efficient converter that will not hold with the lockup commanded on, there could be another 25 or so HP loss at the tires.

What brand converter do you have and what stall??

Mike Norris

I vote Mike Norris for President!!

please help this man Mike!! I am tired of hearing about this truck...lol. Just kidding Walter hahaha. This thing will decimate all once it is figured out.......my monte is waiting....

It does seem that if something is going to go wrong...it is going to happen to us!!

[Hambone!]

I got the tune and have a few concerns for sure. I am going to reply in the e-mail and I would really like to see an HP Tuner log of the best dyno run as well as a look at the dyno sheet with air/fuel reading.

One other thing I forgot to mention is about the 4L80E in that it will show about 35-40 HP less at the tires then a 4L65E. Not saying that this thing should not do 450+ at the tires even with a 4L80E, just saying. And on top of that if you have a less efficient converter that will not hold with the lockup commanded on, there could be another 25 or so HP loss at the tires.

What brand converter do you have and what stall??

Mike Norris

Ok, here's the latest....for some reason, when I asked for the Logs and Dyno info, I once again got just the .HPT file. I didn't realize this until I got the flash drive home of course. So far nothing has been right, and never thought I'd have to stay on top of someone so much and watch everything they do. The converter is an ATM 2600-2800 stall, I hate it at the moment, it's way too loose. Maybe the motor isn't putting out any torque, so it acts looser than it should....but either way, my trans temps are 90deg higher than before, just putting around in traffic. I have the tow package with 2 coolers BTW. I'm at the point I might as well just buy EFI Live's FlashScan and do it my damn self. Evidently nobody in MD knows a damn thing about tuning. Guess I may as well be the first. AFR jumps to 10.2-1 when I blip the pedal, the rpm's pick up as I'm trying to slow down, have to put it in Neutral to stop without riding the brakes. Stumbles on cold start, when coming off idle, when idling, on a warm restart......yeah, all of it. Most of the time AFR is 11 to 11.5-1 when accelerating, 14.5 to 15.2-1 when cruising. Engine slams into the rev limiter before it shifts, then when it finally shifts, its sooooo slllloooooowwww. They couldn't enable pin 42 on my ECM to run E-Fans.... just a whole page of things wrong. Oh, and I guess its my fault for not giving them more than 3 times to fix the exhaust leak on the pipes they bent and installed. It still leaks, had to be leaking on the dyno, no ideal how it wasn't fixed. Also, the first day I picked it up because it was "ready", not only was the exhaust leaking but had a dead miss. Why does Maryland suck so much?

[Mike Norris]

Just sounds like a bad situation. I have never heard of an ATM converter, but that does not mean I know it all. I typically only use Precision Industries, Yank and FTI as they are all very efficient and work well. A 26-2800 stall should not feel loose at all and be damn near stock feeling if done right.

The fact that the trans temps are quite a bit higher could be that the converter is not locking or is slipping when locked. I have seen this in cheap converters before. I have seen a lot of folks buy a $4-500 converter because they do not want to spend the typical $700-850 on a real nice piece, and then have serious issues with the budget converter. Could be some of the issue.

A/F sounds okay, but the stumbles sre not fir sure. The hitting the limiter issue could be wrong shift points or the converter is junk. They should be able to tell you that though one way or the other.

EFI Live is a great tool and lots of support, but I use HP Tuners and if you would like me to help you out it would be best to get HPT. Not saying that you have to go through me, just letting you know where I am coming from. Both systems work well.

Hope this helps and let me know.

Mike Norris

[camcojb]

Just sounds like a bad situation. I have never heard of an ATM converter, but that does not mean I know it all. I typically only use Precision Industries, Yank and FTI as they are all very efficient and work well. A 26-2800 stall should not feel loose at all and be damn near stock feeling if done right.

The fact that the trans temps are quite a bit higher could be that the converter is not locking or is slipping when locked. I have seen this in cheap converters before. I have seen a lot of folks buy a $4-500 converter because they do not want to spend the typical $700-850 on a real nice piece, and then have serious issues with the budget converter. Could be some of the issue.

A/F sounds okay, but the stumbles sre not fir sure. The hitting the limiter issue could be wrong shift points or the converter is junk. They should be able to tell you that though one way or the other.

EFI Live is a great tool and lots of support, but I use HP Tuners and if you would like me to help you out it would be best to get HPT. Not saying that you have to go through me, just letting you know where I am coming from. Both systems work well.

Hope this helps and let me know.

Mike Norris

I've seen a bad converter dynoed before, and a car that dynoed 575 rwhp with the cheap converter made over 900 rwhp with a good converter; it killed the numbers and performance of the car.

I've tuned with HP Tuners and EFI Live; I prefer the HP Tuners for gas stuff, and EFI Live for diesels.

I highly recommend Mike, he is a great tuner. My two cents......... :smoke:

[Hambone!]

Thanks Mike, I've never heard of ATM either, it was spec'd by the 1st speed shop I used here in MD. Even now, I can't find much info on them. I was crazy to rely on the shop, even though they had such a good reputation. Being blinded by that, I was amazed to find out after the fact that lots of folks had issues with them. Moving forward, I picked EFIlive since the people on their forum seemed more mature. I realize that's not a definitive indicator of a product's quality, but I'm concerned about technical assistance in the future. Just do a brief search on EFILive VS HPT on both forums and see what they say about each other. I'm sure either suite would work in the hands of a competent tuner, but I am certainly not one. I've gone through the EFILive tutorials and find them very helpful and the software very intuitive. To be fair, I haven't evaluated HPT yet, perhaps during the week I'll do it. Now that they have a free download/trial period, I suppose I'd better be sure before committing this much time and effort to 1 platform. Just wondering...if you were trying to fix something like this...would you try and repair the tune in it, or start over from stock?

[Mike Norris]

I think EFI Live is a very good tool and both it and HPT will work essentially the same. If I had to do over again I may go EFI Live, but I have no issues at all with HPT. I am with you as far as the HPT board goes, but that can be true about anything and you will always need to decipher between good and bad info.

In the end, pick what you feel comfortable with. I can only really help you with HPT with sending tunes back and forth. I do have EFI Live software and can view logs and tunes, I just can not build a program and send it.

Mike Norris

[MonzaRacer]

Im seriously not impressed with 12 to 1AFR under boost either, seems little lean, not lot but all it takes is a little to hurt something. If its an LS it has a knock sensor, so add timing till it starts rattling, then just before it rattles under boost start pulling timing per pound of boost. peak cylinder pressure makes peak torque. Heck I have heard LSx engine rattle there head off and make super passes at track, but you wouldnt believe what they would do after we tuned them (no dyno, just butt and 1/8th mile)

[SicMonte]

Hey buddy got any updates?

I havent touched the old engine yet...just saying.