Even more ST80 2 Step testing, with good info for 6speed users too
09-24-2008, 11:37 PM
#1
Even more ST80 2 Step testing, with good info for 6speed users too So I took the undead sled out again tonight to do some more 2 step testing on it. I figures some things out, but it's brought up some questions.
I started off testing the car in neutral. Lingenfelter launch control set for 3300 rpm limiter with retard enabled. My total timing on the 2 step in neutral is 5 degrees.
1st observation... holy **** that is loud
2nd observation... holy **** those are cool fire *****
3rd observation... holy ****, i just made 4-5 psi at 3300 rpms on a rear mounted ST80 turbo with a 1.00 a/r turbine housing in Neutral!
This looked promising, but unfortunately, it was short lived. When I loaded it on the converter it would not ignite the fuel in the exhaust and build boost. I didn't try retarding the timing any further than 5 degrees though. So my question is why can't I cause the fuel to ignite in the exhaust when the car is under load. If I could get it to work like it does in neutral, I could leave at a lower RPM and spool faster.
6 speed rearmount guys curious about 2 step tuning, here is your info. 5 degrees of total timing at 3300 rpms, builds 4 psi in about 2.5 seconds.
I guess I could get a looser stall which would allow me to use the 2 step to make boost before loading the converter. The other thing I could do is try to retard the timing even more while on the 2 step to cause ignition. I don't know if that will hurt any thing though.
Thoughts?
PS. adding more timing on the brake/2step hasn't seemed to help, but I'll probably try more testing tomorrow and try 50 degrees of timing to see if it makes a difference.
P.S. I also found out (what I already knew) a 600cc bike is no match for 13psi on 91 octane and 14 degrees of timing. About a bus length from 75-120.
I started off testing the car in neutral. Lingenfelter launch control set for 3300 rpm limiter with retard enabled. My total timing on the 2 step in neutral is 5 degrees.
1st observation... holy **** that is loud
2nd observation... holy **** those are cool fire *****
3rd observation... holy ****, i just made 4-5 psi at 3300 rpms on a rear mounted ST80 turbo with a 1.00 a/r turbine housing in Neutral!
This looked promising, but unfortunately, it was short lived. When I loaded it on the converter it would not ignite the fuel in the exhaust and build boost. I didn't try retarding the timing any further than 5 degrees though. So my question is why can't I cause the fuel to ignite in the exhaust when the car is under load. If I could get it to work like it does in neutral, I could leave at a lower RPM and spool faster.
6 speed rearmount guys curious about 2 step tuning, here is your info. 5 degrees of total timing at 3300 rpms, builds 4 psi in about 2.5 seconds.
I guess I could get a looser stall which would allow me to use the 2 step to make boost before loading the converter. The other thing I could do is try to retard the timing even more while on the 2 step to cause ignition. I don't know if that will hurt any thing though.
Thoughts?
PS. adding more timing on the brake/2step hasn't seemed to help, but I'll probably try more testing tomorrow and try 50 degrees of timing to see if it makes a difference.
P.S. I also found out (what I already knew) a 600cc bike is no match for 13psi on 91 octane and 14 degrees of timing. About a bus length from 75-120.
Last edited by Zombie; 09-25-2008 at 12:39 AM.
09-25-2008, 08:15 AM
#2
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I'd be interested to see what dropping the timing a bit more would do. Easier than swapping converters, but I see your concern.
I'd like to do launch control in the future...getting this M12 GTO going takes some effort.
I'd like to do launch control in the future...getting this M12 GTO going takes some effort.
09-25-2008, 09:40 AM
#3
We have found that on auto cars you actually want to advance timing on the 2 step, and manual cars you want to retard timing.
The auto cars need to make more power when on the converter to get it up on the stall, if you pull timing you will make less power and hence the engine RPM and the boost will go down. (We can get a 91mm 289 Ford to launch at 38 psi using this method).
On manual cars we anti-lag the hell out of then, pulling like 14 degrees of timing. On manual cars you need to build momentum in the turbo, and not really make any power because when you drop the clutch the timing will go back to normal and your boost will still be high.
The auto cars need to make more power when on the converter to get it up on the stall, if you pull timing you will make less power and hence the engine RPM and the boost will go down. (We can get a 91mm 289 Ford to launch at 38 psi using this method).
On manual cars we anti-lag the hell out of then, pulling like 14 degrees of timing. On manual cars you need to build momentum in the turbo, and not really make any power because when you drop the clutch the timing will go back to normal and your boost will still be high.
09-25-2008, 09:57 AM
#4
I'm just posting the results of my testing for everyone. I've had some fast auto guys tell me they retard and other that they advance the hell out of it. I think what you do depends a lot on the converter setup with an auto. If the stall is loose and you can build boost by retarding it before the getting against the converter, it will work great.
09-25-2008, 10:59 AM
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I've used a TCI, Vig and Chance.
I'm sure every combo is combo specific.
I've used 54's, 60's and 76's twin turbos.
I've used a 2step on all of the combos.
Even put a 2step on a buddies LPE 650 TT and retuned the car.
Evey time with the automatics, TB + 2step + 31-38 degrees of advance at the hit worked better....but the key was ALWAYS a proper converter. I've fought converters that are not right for the combo and thought I was losing my mind...major tuning changes had very little effect at the strip...got the correct converter and the car started responding to the tuning changes.....the correct converter is 90% in lauching a turbo car...the tune is 10% IMHO.
I'm sure every combo is combo specific.
I've used 54's, 60's and 76's twin turbos.
I've used a 2step on all of the combos.
Even put a 2step on a buddies LPE 650 TT and retuned the car.
Evey time with the automatics, TB + 2step + 31-38 degrees of advance at the hit worked better....but the key was ALWAYS a proper converter. I've fought converters that are not right for the combo and thought I was losing my mind...major tuning changes had very little effect at the strip...got the correct converter and the car started responding to the tuning changes.....the correct converter is 90% in lauching a turbo car...the tune is 10% IMHO.
