Limiting 1st gear wheel spin - ideas?

[tekdeus]

I have an APEX'I AVCR boost controller that can control the amount of boost in each gear. When I was running a 10psi wastegate spring, I could successfully limit my 1st gear boost to 10psi, and get great traction at full-throttle. I recently had to increase my wastegate spring to 14psi and now I'm getting nothing but wheelspin in 1st gear, especially in the colder weather.

I'm running the stock ECU with an SAFC, so I'd rather not do part-throttle 1st gear launches, since it will go lean (14.7) if the throttle is less than 70%. Maybe it is actually safe at 14psi and 14.7 AFR because my meth kit sprays fully by then?

I was wondering if there was a way to mechanically limit the throttle in 1st gear to 70-80%, so I could use full throttle and get traction in 1st? Some kind of active throttle stop? Any other ideas? I know a standalone with traction control would be ideal but I'm wondering if there is another short-term option.

 

[gofastgeorge]

Softer rear springs.
Wider, stickier tires.
A boost controller that you can set up with a lower setting in first gear.

 

[IJ.]

What WG Brad?

Even if you limit the throttle to 70% the ECU still see's that as 70% via the TPS.

Don't know if you remember how much trouble I went to trying to sort this issue on the 3540r...

 

[lowtaco]

Or even easier, just lift your right foot......

 

[kwnate]

motec + traction control :dunno:

 

[InFrnt0fU]

Whats the width of your rears on the car? Looking like at least 9.5" right?

Sidekickin ur thread: Knowing that I will not have a standalone with traction control capabilities, I was thinking of switching to a 5x120.7 bolt pattern to take advantage of all the oem corvette zr1 wheels available in the 17x9.5/11 fashion. I'm thinking this could be a cheaper option than going with custom volks or something along those lines? Thoughts?

 

[kwnate]

Sidekickin ur thread: Knowing that I will not have a standalone with traction control capabilities, I was thinking of switching to a 5x120.7 bolt pattern to take advantage of all the oem corvette zr1 wheels available in the 17x9.5/11 fashion. I'm thinking this could be a cheaper option than going with custom volks or something along those lines? Thoughts?

Thoughts? GTFO of this thread.

 

[grimreaper]

With a wideband you should be able to watch things as you feather the throttle... I get normal 11-12's afr at part throttle above 4-5 psi. This is with less then 70% throttle. Watch your afr's as you slowly increase boost. Even with a stock ecu it should switch to open loop before psi gets to high unless you totally jacked up the afm signal with the safc. I can hold right at 2-4 psi and stay in closed loop for a few seconds but any more psi and vf's hit zero and afr's drop.

 

[CajunKenny]

Hey Brad! Why did you up wastegate pressure to 14psi?

Unless you’re headed north of 25psi, I’d put the wastegate back to 10psi and let your boost controller do the work. If that’s not an option, try 12psi. Maybe your limiter can manage that better than 14.

 

[tissimo]

Just spin and dance down the road, lol.

But really if you're that worried, look into a standalone with traction control or an aftermarket traction control system. Or just drive when the roads aren't freezing with decent tires.

 

[supra90turbo]

LOL I like how everyone's saying get wider tires.
Not like that is a solution, as we can see, since he's already running 295/30R18's out back, according to his info thread.

May want to look into some drag radials perhaps.

Unfortunately, it seems that this would require a rather large band-aid to make work, I'm thinking hobbs switch, coupled with a 1st gear switch, and something more to retard ignition when boost is over 10psi and it is in 1st gear, making a sort of home-brew Trac system.

Me? I'd just hold it to the floor till the speed catches up. lol

 

[becauseican]

The joys of a 500HP car !!! You wanted a quick spooling responsive car, now thats what you got. Unless you run with lower boost you are SOL. Without a standalone with traction control you are very limited what you can do.....Maybe just drive your DD when its cold and wet out.

 

[gofastgeorge]

Why not just put a weaker spring in the waste gate, so that the AVC-R can do it's job?
(or did I miss something?)

 

[tekdeus]

It's a Tial 44mm. Well, I can go back to the 10psi spring, but then the boost is considerably less stable at the 21-22psi that I run normally, and won't hold 25psi when I spike it with race gas. With the Tial springs available, it was either 10psi or 13psi, but mine seems to go up to 14psi with the 13psi springs.

Me? I'd just hold it to the floor till the speed catches up. lol

This doesn't work so well when trying to beat an AWD Subaru off the line at a stop light

 

[figgie]

tekdeus

without some form of ACTIVE traction control, it is just not going to happen.

 

[tissimo]

tekdeus

without some form of ACTIVE traction control, it is just not going to happen.

Even with active traction control, I dont think beating a AWD car off a stoplight is going to happen.

 

[IJ.]

It's a Tial 44mm. Well, I can go back to the 10psi spring, but then the boost is considerably less stable at the 21-22psi that I run normally, and won't hold 25psi when I spike it with race gas. With the Tial springs available, it was either 10psi or 13psi, but mine seems to go up to 14psi with the 13psi springs.


This doesn't work so well when trying to beat an AWD Subaru off the line at a stop light

Something wrong in the plumbing or pipe work then Brad, I ran a 5psi spring in my V44 and was 100% stable to 24psi.

Most of the things you can try engine wise are counter productive while trying to get traction, pulling timing and cutting cylinders (unless you can cut bot Inj/Ign) just blows unburnt fuel into the header which ignites and spools up the turbo harder and you get more spin.

Close the throttle down some you get the engine into a meatier part of it's powerband and .... you get more spin...

I use TRAC in the MoTeC on the DBW throttle, I cut boost, pull timing and cut cylinders and it's the only way I could get 500rwhp drivable in ALL conditions (it trims the car's power output to suit the available conditions)

 

[Enraged]

what about something like the racelogic systems?

 

[gofastgeorge]

Something wrong in the plumbing or pipe work then Brad, I ran a 5psi spring in my V44 and was 100% stable to 24psi.

+1 on that Ian.
Spongy lines, or too much length can lead to boost instability.

 

[GrimJack]

Brad, do you have both ports on your wastegate hooked up?