This is correct for the rinkrat reference and should be followed. For the RussK idle config, this is the thread. http://www.hptuners.com/forum/showthread.php?30362-Russ-k-s-adaptive-idle-config&styleid=4

It's very simple and people over think it. It's just a config file for the VCM scanner. Load it up, start the car when it's cold, log the results without touching anything and copy+paste into the base running airflow in your tune file. Has to be done at least once each in park and drive.

 

I'm using the Deatschwerks 42 lb injectors & have compared them to stock GM for idle quality & cannot tell any difference. The dial in just as the GM injectors do.

Just a thought on your AC issue, is it possible your base idle timing is to high? If so when timing is being added the motor has no reserve idle torque.

 

I agree on the injectors, they cleaned up my tune over the 8.1 injectors I had before. Previously my idle was 950,disliked it with my current converter. After this injector swap and retune we dropped the idle speed to 850 ad added 50 rpm to AC on

 

Apologies for the slow reply. My LSXRT was new. Have 42 pound injectors.


Everything you said below sounds exactly like my experience with the LSXRT. Tuner worked with it at least five times including dyno tuning. Had another dyno tune with a different tuner. Still had issues. Both tuners were excellent and did their best with the LSXRT. The time was finally driveable but the car stalled a lot.

One of the techiques that helped some with the stalling was jacking the timing up to like 56 degreees (max) at 300-400 rpm to help catch a "stall" and save.

Making sure all physical connections are correct and sure can help too. Confirm PCV is hooked up correctly, confirm brake booster vacuum is pulled from the correct port. Confirm the intake is snug and all bolts torqued to spec. Confirm the TB blade is equi-distant on all sides with a feeler gauge. If TB blade is off center it may cause idle issues. Playing the idle decay can help, slow idle decay can help reduce stalls. All of this is band-aids but can help. Called FAST several times but never got thru...they should put a detailed trouble shooting guide on their website for this intake and it's tune issues.

Replaced LSXRT intake with a Peak Ported LS6 with TPiS 90mm snount - all driveability issues instantly fixed. I've very happy driving the car now

Tested a Fast 92 intake and TB - driveability issues instantly vanish.

The PP LS6 TPiS 90 stayed on the car. It had the best driveability. As in drove like stock. The car has stalled ONE time in two months and that was driver error on my part. Idles nice at 700 rpm

My RS with its 383 LS1 stroker and little 229 cam responded better toto the 90mm intakes. I hated to see the LSXRT not work out for my car...

So it's now a X-LSXRT and is sitting on a shelf in the garage.

 

99 Blackbird, your tuner(s) failed you.

I daily drive my LSXrT intake with that crappy FAST 102 tb and a 239/244 cam on a .060 over 6.0l (375cu"). Works fine for me. BUT, like I said before. You need to enlarge the IAC passage and I've now found that shifting the Desired IAC Steps vs. Desired Idle Effective Area to the right 8 cells or so fixes a lot of issues since the FAST IAC port just doesn't flow as much air. That along with a correct idle fuel and timing curve with lots of smoothness will work for just about every car. Along with small tweaks to the throttle cracker and follower, my car starts, drives smoothly and returns to idle without hanging or stalling at all times...except for some cold-start tuning I haven't nailed yet. Just switched from a MAF tune back to SD full-time and it still runs great.

 

1970camaroRS, I feel validated to know the LSXRT can work. I wanted so bad to have it work for my car but it didn't with the resources available.

How many hours did it take to get yours dialed in?
Would you consider writing a primer for how to tune an LSXRT?
I think that would make a fantastic sticky.

Btw Cold starts worked pretty by the time the LSXRT was replaced. Had some hot start issues but that's another story.

 

I have been to two different reputable tuners with no luck. I did dump the 102 FAST tb for a smaller BBK unit. I really think its the intake Like you I REALLY wanted it to work but..... I just got a TBSS intake to swap and see if all the weird issues go away. My motor should be mild enough to never notice much difference. Still dies randomly worse when AC on and using the timing to try to catch a stall it surges real bad in 5 mph range like stuck in traffic

 

You do understand that the idea of "reputable" tuners is a sick joke, right. While there are MANY good tuners, the problem is that the reputations come from tuning for people who don't know any better. The people who would actually know the difference tune for themselves. This leads to a profitable existence for a lot of hacks who can barely copy/paste someone else's work.

 

First time with the LSXrT and 102 TB, it took me about two days worth of tuning, so 12 to 16 hours, to get it reliably driveable in stop-and-go traffic. Then another day at the track for WOT tuning and a few days worth of long drives to work and back to fine-tune everything else. My new combo took considerably longer, but I was also fighting a really stupid issue with loose rocker bolts. But it runs better with the larger cam than it did with the smaller cam. I believe this is mostly due to the modification of the IAC passage the shifting the table in the tune.

A primer? Maybe I will. It's pretty much the same as any other large cam N/A tune except for the attention given the IAC passage. Idle fuel and idle timing, RAF, VE, timing, MAF, fine tuning throttle follower and cracker.

And what I mean by cold start is that my only issue at the moment is that sometimes from a cold start, before completely warming up, I will encounter a slight surge that sometimes goes over the tipping point and stalls the engine. Most likely a fueling problem, but I haven't really attacked it yet to see.

 

Are you saying that you had to do both of these to the FAST 102 TB:
- enlarge IAC passage in TB (if so, by how much)...?
- shift the IAC Steps vs Effective Area table to the right...?

Which IACV did you use.

Thanks.

 

I wouldn't say you have to do both, but I did and it's working great. I enlarged both the front and rear passages between the IAC valve on the TB using an air grinder and did my best to smooth the entry and exit transitions. Wish I'd taken pics of it before installing, but I didn't. Not sure how much bigger they are, but it's bigger than how it came, but not so big that a 3/8ths bit fits in it. If I had a drill press with a vice, I would have just drilled it out to 3/8ths.

Here's now my IAC steps table looks like after I shifted everything over.


And compared to stock.


It was trial and error and I did it 4 or 5 times until I had it shifted enough. The car experiences no surge, hang and anything like that. In fact, for the last few days that I've been tweaking on a OLSD tune, the car hasn't surged once. Of course, you MUST tune the RAF correctly as well...

 

3/8" drill out IAC passage, understood.

Trial and error on desired air/step table shift, understood.

RAF, understood.

Thanks, appreciated.

 

I have seen some FAST throttle bodies work OK and some that are junk, seems like none of them are exactly the same so don't be so quick to blame the tuner because some are just terrible. And I'm talking about swapping it with another on the shelf back to back and they were wildly different so it seems their quality control is in the toilet.

 

Yeah I see the same thing with alot of aftermarket TB, not only fast.

 

Yeah same here, just the FAST TBs seem to be the worst of them.

 

1970 Camaro RS, thank you for sharing this information.

Nova404, please post details of how the TBSS intake works compared to the LSXRT.