Building boost on line??
06-13-2011, 07:37 PM
#1
Building boost on line?? A few weeks ago I did my first round of shakedown passes and things went well except that I was not able to build any boost on the line. My 60's suffered as I was only able to cut a 1.70 60'. I was under the impression that with a trans brake I would be able to build boost on the line coming off the brake but I guess I was wrong so what is the best way to build boost on the line? Thanks in advance.
06-13-2011, 07:52 PM
#4
I am assuming you are talking engine timing? I am not 100% as I did not tune the car, I do have HP tuners and the tune file but I am at work right now and can not look at it. Will lower timing or higher timing allow you to build more boost for launching?
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06-13-2011, 09:04 PM
#10
Well, that is not entirely true...
http://youtu.be/q8xOQpEMzWQ?hd=1
This launch was 7psi off the brake
http://youtu.be/cyqkIrTeo-0?hd=1
I agree that the best way is with a two step, but its not the only way. With that said, we will be using the two step the next time out.
Sean
http://youtu.be/q8xOQpEMzWQ?hd=1
This launch was 7psi off the brake
http://youtu.be/cyqkIrTeo-0?hd=1
I agree that the best way is with a two step, but its not the only way. With that said, we will be using the two step the next time out.
Sean
06-13-2011, 10:52 PM
#12
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I use my lpe 2step to build boost while staging with footbrake, but when the 2nd bulb lights up I hit the trans brake and the boost keeps climbing without the 2step. I wish I had a 3step but this works good enough
06-14-2011, 05:12 AM
#13
06-14-2011, 07:08 AM
#14
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i can build 15 psi on the brake without the two step with it i can adj boost from 7 to arround 12. by adding rpm adds boost. but if you cant dead head the converter and build gobs of boost then id think the wg is stayinig open or something the most load
gona get is dead on the converter the two step would be a load but at a lower rpm will also mean less pressure
gona get is dead on the converter the two step would be a load but at a lower rpm will also mean less pressure
06-14-2011, 11:58 AM
#16
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i have a MSD 2-step, super easy hook up, only 1 wire to hook to the hot wire going to trans brake noid, then plugs between the harness and coils.
been 2 years and i havent had any problems with it.
i was able to build boost on my t.brake without the 2-step, but the msd makes it alot easier. just double bulb, hit the button and floor it, makes a more consistent launch.
been 2 years and i havent had any problems with it.
i was able to build boost on my t.brake without the 2-step, but the msd makes it alot easier. just double bulb, hit the button and floor it, makes a more consistent launch.
06-14-2011, 12:21 PM
#17
Well it could be related to my exhaust housing being too small. My exhaust housing was too small and it was creating major back pressure which was opening the gate too early which is why I was only able to make 8 psi of boost. Going to a bigger housing this week which should remedy this and bring the backpressure down. Maybe then it will build boost off the brake as well.
06-14-2011, 12:29 PM
#18
i have a MSD 2-step, super easy hook up, only 1 wire to hook to the hot wire going to trans brake noid, then plugs between the harness and coils.
been 2 years and i havent had any problems with it.
i was able to build boost on my t.brake without the 2-step, but the msd makes it alot easier. just double bulb, hit the button and floor it, makes a more consistent launch.
been 2 years and i havent had any problems with it.
i was able to build boost on my t.brake without the 2-step, but the msd makes it alot easier. just double bulb, hit the button and floor it, makes a more consistent launch.
You wouldnt happen to know the part number would you?
06-14-2011, 12:38 PM
#19
Well it could be related to my exhaust housing being too small. My exhaust housing was too small and it was creating major back pressure which was opening the gate too early which is why I was only able to make 8 psi of boost. Going to a bigger housing this week which should remedy this and bring the backpressure down. Maybe then it will build boost off the brake as well.
What RPM are you trying to leave @?
Are you flat on the floor when staging?
Do you have dual rear brakes?
Motor is a 390...what size turbine/turbine housing?
You need a box with a 2-3 step. 2 limiters down low.
06-14-2011, 12:43 PM
#20
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lots of bad info in here...
two step/three step for an auto car only control rpm/total boost...not the ability to build boost
if you can't build on the brake against the converter, you aren't building any on a 2-step either
potential problems:
wrong cam
exhaust leak
boost leak
wrong converter
wrong turbo size
too much fuel
not enough timing
not enough compression
etc
two step/three step for an auto car only control rpm/total boost...not the ability to build boost
if you can't build on the brake against the converter, you aren't building any on a 2-step either
potential problems:
wrong cam
exhaust leak
boost leak
wrong converter
wrong turbo size
too much fuel
not enough timing
not enough compression
etc