bigturboz28

For a Manual Car:
1. What do you retard the timing too with the 2 step engaged?
2. What AFR do you target with the 2 step engaged?

98Z28CobraKiller

iTrader: (17)

Typically you would advance timing on a stick to build boost on a 2 step and retard it with an auto. I target the same AFR regardless of 11.5-11.9:1 and dont mess with timing yet.

ddnspider

iTrader: (26)

INCORRECT. You RETARD timing with a manual and ADVANCE timing with an auto. Retarding timing on the stick helps cause unburnt fuel to spool the turbo off the line.

bigturboz28

Thanks, but does anyone know how much timing to retard too?
Also, is the consensus approx. 11.5:1 AFR?

ddnspider

iTrader: (26)

Are you using like a LPE 2 step for example? most try the 2 step out with no timing retarded and see how well it works then slowly retard more and more timing until the desired result is achieved.

chuntington101

bit off topic but the WRC cars used to retard the timing SO much that even at WOT and with 15psi boost with no load (out of gear) they would still hold the rpm back to about 5-6Krpm! pretty bonkers! lol

98Z28CobraKiller

iTrader: (17)

Whoops. That's what I thought but it came out backwards.

bigturboz28

Thanks for all the feedback (no sarcasm intended) but does anyone have an answer to the two original questions?

For a Manual Car:
1. What do you retard the timing too with the 2 step engaged (or what have you found to work well)?
2. What AFR do you target with the 2 step engaged (is approximately 11.5:1 what others target)?

tomz28

iTrader: (20)

with mine i found that the car liked it set at 4500 or higher and no retard and it would make 7.5 psi i cut a 1.67 60 foot at 4500rpm lunch and a 3.42 gear still working on it

for the AFR i would not worry about it because its going to go rich as hell do to the spark being cut out

but you need to start low and work your way up and see what works best for you man go have fun with it thats my 2cents

98Z28CobraKiller

iTrader: (17)

Mine makes about 7 psi at 4K RPM with the base 13* that I am running. I 60' in the low to mid 1.4's. I tuned the car to run 11.5 target and have it setup to error towards the 11.9 mark. I did no special tuning specific to the 2 step.

tomz28

iTrader: (20)

is that a auto car and what gear ?
your car looks like it runs sweet!

blacksi

iTrader: (3)

So you only run 13* of timing? Just wondering, I'm running 17 18*.

tomz28

iTrader: (20)

im only running 12

blacksi

iTrader: (3)

Any reason for so low? Do you get knock above 12 or just being extra safe?

tomz28

iTrader: (20)

just safe its up to 14 now but its just a stock bottom end and i run 12psi sometimes

Super Slow SS

iTrader: (9)

Sick, I dont trust that but I agree with the timing. I dont think I would run 18 on a stock bottom .. even at the cost of power

blacksi

iTrader: (3)

That makes it a little more understandable, I wasn't thinking of being stock.

98Z28CobraKiller

iTrader: (17)

Yeah, I run a RMVB TH350 with tbrake and about a 4500 stall from FTI. It currently has a 3.73 gear but due to the lowering of my rev limiter to 6500, I'm out of gear by about the 1200'-1250' mark. I have done pretty much all the suspension mods. The chassis had a 408ci + 380 shot and has been 9.33 @ 146. I didn't (still don't) have the money to forge the bottom end and throw my heads on it after blowing up my old setup. I decided to throw in a cheap stock iron LQ9 long block and get the turbo kit all fabbed up so I could get back on the road.

As far as timing is concerned, I figured that it might last a little longer at 13* seeing as though I am hitting it with 15-16#'s on 93 octane.