LS3 Magnuson Heartbeat Throttle Flare

[greg666]

I wonder if any one can help me with throttle flare when i change from 4th to 5th and 5th to 6th between 1000 and 2000 rpm, attached is log file at 9.22.06 when i push the clutch in 4th gear it flares 500 rpm. SD Tune

[Alvin]

It's likely too much airflow in Base Runing Airflow, Airflow final minimum

[greg666]

Ok i will try lowering it, its at factory settings now and cam is an LS9

[GHuggins]

See how this one works out for you. Adjusted a few things for the throttle hang and to help with engine braking.

[greg666]

Tried that file thanks, still doing it but not as bad, as soon as you push the clutch in anywhere between 1000 and 2000 rpm it flares under high load, 1st to 3rd gear hardly noticeable, hills make it worse, it seems like the throttle butterfly has a delay in returning even though you have taken your foot off the accelerator, i also set cfco timing to 0 degrees this help reduce it but probably only masking the real problem, please see attached log file

[GHuggins]

Is the blower the only mod on this car?

[GHuggins]

See if this doesn't have your problem close to taken care of.

[greg666]

Magnuson Heartbeat 2300, 90mm pulley, LS9 Cam, Lsa Injectors, VCM OTR, 1 3/4 extractors, 2 1/2 Exhaust, see attached photo

[Alvin]

Ok i will try lowering it, its at factory settings now and cam is an LS9

Did you copy anything else over from a LS9?

This is generally not a good idea. Just a heads up.

You can also clean this up fast using the idle adaptive spark tables and base timing tables.

[greg666]

I only put the ls9 camshaft in the car, i didnt copy the software, i just copied lsa injector data, it was the same problem with the standard ls3 cam, i have already tried the adaptive idle by halving the timing and halving again still the same, car is running perfect except for this. Might be something to do with the throttle body as it is upside down now compared to the standard installation or its faulty

Just saw that Second file with give it a try

[Alvin]

Go the other way on the adaptive idle stuff

[GHuggins]

That second file should have it fixed. It's been a while since I tuned just a 2300 install - mainly because magnuson was supposed to have discontinued them with the better 2600's taking their place and most people always want to do more than just the blower anymore. I still had all of the standard maggie installs under my older filing system, so how to go through some customers names to find one. Granted they were pretty much all vette's, but those changes should have you sorted out.

You can also do like Alvin mentioned and mess with the adaptive timing, but I can tell you that in the corresponding file I had lowered it to help smooth things out, but it didn't have any hanging idle issues. Idle was also addressed on the main adaptive proportional and integral side of things - I made those changes in the last file I posted too... I always find it best to dial in the controllers whether it be the trans or engine side then to just change the "controlled"...

If it's still got issues after those changes it may just need a light bit more massaging, but should be really close.

[greg666]

Still doing it but improving, as soon as the clutch goes in and the clutch switch operates thats when it happens, i might change the throttle body to rule it out, watching the tps from the log files it seems to be returning too slow. 11.05.24 onwards log file

[GHuggins]

The second it sees neutral it's closing at least from what I can see - have you done the usual three pedal pumps to learn the clutch position after each reflash? You can try another TB - it is possible it's getting weak - the upside down flip is harder on them, so could be an issue. I always found it better to modify the housing of the body where possible to install them the "normal" way, but this won't be possible on yours - it's pretty tight...

[greg666]

No i didnt know about the clutch pumps will try, 102mm dbw throttle body's are cheap on ebay here $178 or $137 for 92mm standard size, chinese but should work, not shore how good though, but enough to rule out the throttle body

[GHuggins]

Stay away from the chinese stuff with a blower - especially a pull through. Takes a pretty stought motor to work one with that kind of vacuum. I already have your min air lowered a lot from what it was not to mention settings to close it better, but you can try expanding on it more.

[greg666]

Apparently LS2 throttle body rotates the opposite to ls3, but on mine the ls2 one would rotate the correct way

[greg666]

Pulled the throttle body apart nothing wrong with it, so it sits in a neutral position at rest partially open with no spring tension, so to open it the motor drives against spring tension and to close it completely the motor again drives against spring tension the opposite way, so the problem is in the software somewhere when its driving it closed

[Alvin]

Have you put the adaptive spark control back yet? maybe even make it more aggressive?

Stay far away from the chinese throttle bodies..

[greg666]

I am using lsa adaptive spark which is more aggressive than original, i have also changed to lsa throttle follower and cfco spark of 0 degrees all these have reduced the flare quiet considerably, it will do for now. I have a 2005 LS1 same as LS6 in USA with electronic throttle it has none of these issues.