SD2 tuning

[Scoobum]

Jason - pop the wastegate arm off and wire the gate open, then take it for a run. That should take some drive pressure off the turbo and determine if it's back pressure.


Check all the stupid stuff.

Jeremy, I know you keep up with Sloppy Mechanics. This same issue cropped up with the 6L Sonoma. Yeah, it was something stupid. The erratic WB might be a tip off. I'd look there first. It'd be a simple fix.

[nocooler]

Yeah it's always a good idea to calibrate them often, if they have that feature.

[good2win22]

Exhaust plug somewhere? Do you run a cat converter? Can you open a dump?

No cat. 2.5 pypes with pro race muffler. They are a straight thru muffler. I do have a dump in place of the cat.

Jeremy, I know you keep up with Sloppy Mechanics. This same issue cropped up with the 6L Sonoma. Yeah, it was something stupid. The erratic WB might be a tip off. I'd look there first. It'd be a simple fix.



No erratic WB readings. Set the AFR at 10.7 and it's pretty consistent. Log at the house. Can upload on Thursday. I have a spare WB O2 sensor setting in the box. I could change it but don't believe there's a reason to yet

[TexasT]

Link to this sloppy mechanix problem. I'd like to be able to keep up. I searched and came across a nifty turbo regal with a 6L that was sadly stolen and stripped. Didn't see a problem noted other than the theft so I'm thinking that ain't it.

[nocooler]

The error brad is talking about: Matt (sloppy mechanics on YouTube) setup his new Holley ecu and the wrong wideband configuration was set. It was set for a ntk sensor instead of a Bosch- and it caused all sorts of fueling issues.

Can you turn wbo2 correction off? Is the map sensor reporting right? Sorry I don't have the powerlogger software to view the logs.

Usually when a turbo ls doesn't rev they check valvespring, spark and backpressure

[TexasT]

http://www.turbotweak.com/forum/index.php?threads/powerlogger-software-and-installation-docs.1687/

You can unload the powerlogger above. Works good for looking at logs. I have it on the desktop at home.
 

[good2win22]

Made a run with the waste gate wired open and had the same results. Still won't rev past 5200. It doesn't fall off a cliff when it happens. It just kind of stops going.


Anyway, I think I have identified the problem. Have to confirm first

[good2win22]

Anybody on here running a cam from Comp in the XFI family of lobes? If so, which lifters did you use?

[good2win22]

I guess I'm the only guy on here running XFI lobes.


Lots of reading/researching this weekend and spent a few hours on the phone with Comp cams, Mike from full throttle, Joe from Johnsons lifters, Tim from TA performance, that old fart Nick won't answer his phone and lastly jack Laswell.  Supposed to get a call back tomorrow from Webers and I was supposed to call Dave Husek but time got away from me. 


I didn't realize there was a sub culture of folks that like to spec out cams...  And although some facts remain consistent, each person has a different theory and approach.  Some think my spring pressure is enough on the seat and over the nose and then there are some that believe I don't have enough spring.  Some feel a short travel lifter will fix my problem and some think my lifters are fine. Some feel that a limited travel lifter would work.  Some have methods of setting lash that I have not heard of or seen but that's not hard to believe. 


A few things are for sure, I'm convinced that I do not have an ignition or an exhaust pressure issue but I am more confused than ever about aggressive cam lobe rates, lifters and spring pressures.


More reading and research is required on my end as well figuring out who's information I will choose to trust.

[daveismissing]

Paul Miller's approach is quite different again

[TexasT]

First question: What qualifies as an xfi lobe? I'm guessing it is a comp brand cam(you called em). Did they have recommendation s for a lifter and spring pressures to shoot for? They ground it I guess, one would think they might have a good idea what would work .

I'd definitely get on the horn with d husek, if for nothing else than to say hi from Texas. He probably has two cents to add as well.

Is it a difficult thing to add some spring pressure, swap in some different springs to add some and see where it goes. Is this a roller cam?

Glad you are making some head way.

[nocooler]

Did you buy everything together from one place? My LS has some pretty angry lobes and the springs were supposed to be setup for 155# seat. But I'm running a stock ls1 lifter.


I'd check lash first. Pushrods the right length?

[good2win22]

First question: What qualifies as an xfi lobe? I'm guessing it is a comp brand cam(you called em). Did they have recommendation s for a lifter and spring pressures to shoot for? They ground it I guess, one would think they might have a good idea what would work .

I'd definitely get on the horn with d husek, if for nothing else than to say hi from Texas. He probably has two cents to add as well.

Is it a difficult thing to add some spring pressure, swap in some different springs to add some and see where it goes. Is this a roller cam?

Glad you are making some head way.

If you look at Comp's master cam book, they have names for different lobe profiles. XFI stands for extreme fuel injection. It's lobe has an aggressive ramp rate and was designed for the newest LS engines and specifically a beehive spring that comp designed. This cam that I got off of Charlie was a custom grind using loves from that XFI family of lobes. Allegedly, that lobe is harder on springs.  The folks on the phone at comp don't appear to have the greatest knowledge about their products. This cams profile, duration and lift is not something crazy or oddball just a bit aggressive on the ramp rate.


As long as there is room to not run into spring bind, I could add shims under the spring locaters for an increase in seat and over the nose pressure with the current springs. Changing to Beehive springs for me would require different keepers and locks.  Yes this is a roller cam.

Did you buy everything together from one place? My LS has some pretty angry lobes and the springs were supposed to be setup for 155# seat. But I'm running a stock ls1 lifter.

I'd check lash first. Pushrods the right length?

I did not purchase the valve train from one place. I believe the lash to be set correctly and the push rods to be the correct length. I believe my problem lies with the lifter but that has yet to be confirmed

[TexasT]

I've seen behive springs for our heads. I will have to look at the comp site and see what the deal is. These roller lifters you are using at least similar to the lsx lifters? I'm not a big fan of cams that "test" the reliability of the valve train. I understand why you want to, just personally would rather have reliabilty and longevity over those last three or even thirty horsepower.

I'm betting you get to buy keepers and such and need those beehive springs. Maybe you can figure out a workaround.

So, I'm perusing the comp cams site and unloaded a PDF of their wares. Came across this in the hydraulic roller units. They seem to think you need the beehives. The ovate ones according to the description.


upload pic

[good2win22]

Rich,


From the pic you uploaded, you can see the two lobes that are on my cam.  3013 on the intake and 3012 on the exhaust. Not so certian on there beehive springs working for me. I can get a negative cut retainer and retain the same locks. Also, I can add more shims under the locater. One worry spot is the retainer clearing the top of the valve stem seal.


I also heard new theories today from Dave Husek and Brian Weber. Their ideas of setting valve springs close to coil bind amongst other things. Brian also thinks that I don't have enough turbo. Heck I can't even get past 5200 rpm much less put the turbo all in. Crawl, walk, run method for me