G5X1 114 on C6 LS2

[ingsteve]

Hi,
i'm going to install a g5x1 cam 114LSA on a C6 LS2.
Actually the car has K&N CAI, Fast102, 1-3/4 LT Headers, Borla Touring and tune with wideband on 91octane.

Anybody with similar setup that want to share opinions?
What do you normally do for idle tuning?
I have stock throttle body, there are some install guides over internet that suggest to enlarge the hole on the TB...do you recommend it?
I think it might be controlled with tuning only without any modification on TB...also min IDLE rpm with similar setup seems to be 850-900.

Suggestions,opinions?

[MikeOD]

Don't modify the throttle body. What's the cam lift/duration?

[ingsteve]

As per lg spec
G5X1 int/ex dur 228 232 int/ex lift .588 .574
I purchased the complete kit on 114LSA to have a smooth idle.
So do you think the tune is enough? Me too...but of course i'm not an expert on cams like you guys

[Badassbird]

Yes the tune will be enough. This will be very easy to get to idle.

[ingsteve]

Thanks for the reply.
Honestly 900rpm seems higher as idle rpm...i hope to get a lower idle...i have e40.
What do you think it would be good for spark at idle?
Also the rev. limiter some people say +100rpm than stock (6700rpm), some other ones say more (7000rpm)...i don't want to get any single hp out but only to maintain something reliable, i'm not going to change the springs every year...

[Badassbird]

Should be able to get that to idle at 750 to 800 no problem. 6700 should work fine also for a limit.

[ingsteve]

I don't understand what setup some people have to raise the rev to 7000....maybe it is only an additional risk...

[Badassbird]

There are many combos that we do that will make peak power beyond 6800 rpm and in order to take advantage of that type of curve you must shift beyond that by a few hundred rpm. These are extreme and very high hp applications not mild daily friendly vehicles.

[ingsteve]

Very clear...what afr do you suggest at wot? 12.5 flat? Safety for me comes first than a couple of hp lost...

[MikeOD]

Target lambda 0.85 for safe fueling in an NA setup.

[ingsteve]

Lamba 0.85 = 12.5 AFR of course for gasoline (i use 91)

[MikeOD]

Yeah, I don't know if you can buy normal gasoline in Italy, where I live, I can only buy 10% alcohol now and 12.5 would be lean...but 0.85 lambda is still 0.85 lambda.

[ingsteve]

except diesel, we can only buy 91 gasoline 1.85€/liter or 93 gasoline 2€/liter as per last price on the pump.
I was thinking about lambda on Champagne...but it is still lamba as you said...
I will try with flat 0.85 lambda, as i'm tuning on the street...

[ingsteve]

update.

Car is running well, the starting tune provided by LG was quite ok.
I have tuned the car in maf only cruise/part throttle and wot (@12.5 wideband).
Then i have done some tuning with WB on open loop SD (failing the maf) and after i re-enable the maf only above 3600rpm as per factory settings.
Idle (thanks to 5litereater guide) has been settled down to 750rpm by revising airflow baserunning table.

Now the problems to be solved are :
1) surge-bucking @1200-1300rpm in 2nd,3rd or 4th gear...it seems like to be at 400rpm with the stock cam with the car that seems to stall till i push the clutch...for instance you can go at 1000rpm in 6th gear with having no problem of bucking-surging but in that range it is really shaking back and forward...
I attach a log with previous tune (log4), see frames 572-605,673-690,4450-4500,5391-5410
I have made some adjustment on tune log5 but i didn't have time to check if it is better or not due also to bad weather

Suggestions?

Improvements :
1) i would try to increase the timing at wot, specially on 3800-5400rpm as i feel the car push very hard only after 4500-5000rpm. I have done 3-4 logs to match the maf at 12.5aft with my wideband. No knocks found (min level increased from stock 50mV to 75mV). After 5000rpm the timing seems ok for a 90-91 octane setup. I don't have the possibility to tune on a dyno but only on the street or track.
2) it seems lg completly disabled TPS trip check, i may come back later and increase by a percentage some tables
3) similar of point 2 for misfire
4) perform some more sd ol tuning

What do you think of my current tune?

Thanks.

[SultanHassanMasTuning]

make adjustments to the coast down cruise timing

[ingsteve]

not sure what you mean...do you mean the idle adaptive spark control?
Should i have to set the coast tables (both over and underspeed) the same as in gear?
Or you mean Idle spark advance table coast to be set the same as base? I might try removing 2-3degrees in the area where it is bucking...i think also the HO spark table should be modified in the same field but i'm not sure...HO table should have some more spark if i'm not wrong but maybe too much difference from the coast down table can create surging...
I can try but disabling with vcm control the adaptive spark (by on) didn't solve the issue.
Should i increase also proportional and integral rpm by a few points?
Thanks for the support