question LTX-8
 

my LTX8, came WITHOUT any installed intake air temp, AIT, provision.
it was ordered as a race only , vendor said ait, not needed if i lived in hot climate, TX. FL. PR.
would be fine on street, using coolant sensor!

OK! it does work well for most everything,, starts hot or cold noproblems,, had it dynoed for streetability thats OK too. AEM wideband

But 2 things not satisfied. #2 has me worried
#1 when hot in traffic it wants to stall at idle?? 80-85C, idle rpm 900,, OK if not fully hot.

#2 ,( most important) after making a fast street run, 130-140mph, 18-20psi,, AEM reads 10.5-10.8,, slow down to around 65-70mph AEM reads lean, like 16.5-17, holding steady cruise, so i let off quick, everyone else leaves me behind , most annoying!! and its right around staging 3000rpm, and boost still reads 6-7psi. if i accelerate slowly reads mid 12s

what do you think, aint hurt anything , YET!!!!
THX Ron

nothing to do with your air temp sensor

your tune is shit.

Sounds like staging is all over the shop and sounds like your idle is too lean.

THX, rx72c,,, i will richen idle at that point, been in hi 12s but seems it likes low 12s!!
where would i start on stage? should i richen up at manifold press. at that point or rich up at rpm, or change stage rpm on-off????

Ok. Lets start by telling me what injectors you have,

when you have the secondaries coming on, Both rpm and map.



get your idle around 12-12.2:1 and it should be stable.

HI, rx72c,, injectors,, primary 850s,,, secondarys 1600 blue


map stge, 02"


rev stge 3120 rpm
stge +83%


ignition 4 crane LX-92


2 crane HI-6+2

plugs 6725 leading,, NGK 9 factory trailing


idle wanders around at 11.9- 12.3, on AEM wideband, but no stalling(good)

THX Ron

also rx72c,, you say that in one of your posts you run all ignition timing ATDC,,( after top dead center)

could that be a missprint ???
10-14 psi,, 12 atdc
16-18psi,,,8 atdc
20-22psi,, 6 atdc
30psi,, 2 atdc

that seems like its advanciing timing,, not retard on hi-boost,, what dont i understand?

Thats retarding alright.

2 degrees of timing on 30psi of boost has retarded around 23 degrees of timing:)


If you want i can give you a load map for your injectors that will work alot better.

I can see your problem already.

Staging 1700cc injectors at 3000rpm is your problem.

Bring them on at 2000rpm

Show me your load map

rx72c
 

Hi, back again,, load map as copied from hand held, 40psi base fuel press.

min. ms. .95
24"hg,, .95ms

18",, 1.05ms

12", 1.38ms.

06", 2.14ms.

00", 2.71ms.

2psi,, 3.10ms.

4psi,, 3.62ms.

8psi,, 4.05ms

10psi,, 4.62ms

14psi,, 5.24ms.

16psi,, 5.76ms.

20psi,, 6.67ms

24psi,, 7.24,s

28psi,, 8.19ms


thats it watcha think

THX for your help

Load map looks fine.

Just dial the Staging rpm to 1320 rpm.


Should make it alot better.

dropped stge rpm down to 2000rpm, just about perfect now.
cant feel transistion , just afr richen up on gage, pulls like crazy.
its a street car so mpg is a factor , cruse is 15.2=15.6, at light throttle.
idle 12.0-12.5.

YUP!! smooth as SILK.

THX for your help, RON