Building boost off the line
07-22-2014, 03:45 PM
#1
Building boost off the line OK,
My converter stalls at around 2900-3000. My s475 doesnt zero out the boost gauge till 3400 driving around. Does this mean foot braking aint going to happen?? Should I get a restall to ~3400?
I tried the 2 step, no boost off the line with the foot brake. Best I can do is to get the gauge to zero-out at about 3000 but then the tires break loose. Tried retarding the timing, nothing. Tried leaner/richer afr - nothing either - all on the footbrake.
What else can I do? Thinking transbrake but footbrake would be nice.
Converter is a Trans Spec "low stall" 10" 2900-3300 unit. Not ready to put it in the trash just yet.
My converter stalls at around 2900-3000. My s475 doesnt zero out the boost gauge till 3400 driving around. Does this mean foot braking aint going to happen?? Should I get a restall to ~3400?
I tried the 2 step, no boost off the line with the foot brake. Best I can do is to get the gauge to zero-out at about 3000 but then the tires break loose. Tried retarding the timing, nothing. Tried leaner/richer afr - nothing either - all on the footbrake.
What else can I do? Thinking transbrake but footbrake would be nice.
Converter is a Trans Spec "low stall" 10" 2900-3300 unit. Not ready to put it in the trash just yet.
07-25-2014, 07:05 AM
#3
I have a PTC converter in my car and it only stalls to about 2k on the footbrake. I have the Holley Dominator EFI in my car for the boost controller. I wasn't able to build any boost on the footbrake either until we went into the boost builder function and had it pull out all of the timing (0*) and set up the fix fuel table to 150 lbs/hr. When we set it up like that with the two step was engaged I was able to build 4#'s on dusty concrete shop floor.
Here's what I was told by others:
"You will need to wire up the two and 3 step functions. Here is what I would HIGHLY recommend. Set up one rev limiter on a WOT switch connected to your foot brake. This will allow you to hold the engine at a set RPM on the footbrake and begin to build boost.
Then set up the other rev limiter to come on when your trans brake solenoid is active.
What you will do is pull up and light the first beam. Pump your brakes really good. Hold that brake pedal down like it owes you money and go WOT. When you hit that rev limiter on the footbrake you can then slowly creep in and light the second bulb.
Once you light the second bulb grab the trans brake. You'll want the limiter on the trans brake to be 400-1000rpm higher than the one on the foot brake.
THIS is where boost builder comes in. Wire in the boost builder to only be active on the trans brake. What I do is use normal N/A timing on the foot brake to help start getting boost built. Since there is no load, even with N/A timing at 4-5-6psi of boost you will not detonate. Once you get 4-5-6psi built on the foot brake, you can transition to the trans brake. Once you grab the trans brake and the boost builder comes active, in the boost builder table in the tune up you will pull 10-15 degrees of timing from whatever timing you had on the foot brake. You'll also add fuel. This will move the combustion to the exhaust and start popping and banging.
If you can't get enough boost built this way, there is no hope!
If you don't care about cutting a good reaction time and don't plan on ever racing anyone at the track and just going for fun you can skip the foot brake portion and you can pull in and light both lights, grab the trans brake and have boost builder active on the trans brake and sit there until you get enough boost to launch with.
If you don't have a trans brake, you can set up the boost builder to work on the foot brake with a WOT switch. Have it pull timing and dump fuel on the foot brake only. You should still get good boost built this way. "
Good luck
Here's what I was told by others:
"You will need to wire up the two and 3 step functions. Here is what I would HIGHLY recommend. Set up one rev limiter on a WOT switch connected to your foot brake. This will allow you to hold the engine at a set RPM on the footbrake and begin to build boost.
Then set up the other rev limiter to come on when your trans brake solenoid is active.
What you will do is pull up and light the first beam. Pump your brakes really good. Hold that brake pedal down like it owes you money and go WOT. When you hit that rev limiter on the footbrake you can then slowly creep in and light the second bulb.
Once you light the second bulb grab the trans brake. You'll want the limiter on the trans brake to be 400-1000rpm higher than the one on the foot brake.
THIS is where boost builder comes in. Wire in the boost builder to only be active on the trans brake. What I do is use normal N/A timing on the foot brake to help start getting boost built. Since there is no load, even with N/A timing at 4-5-6psi of boost you will not detonate. Once you get 4-5-6psi built on the foot brake, you can transition to the trans brake. Once you grab the trans brake and the boost builder comes active, in the boost builder table in the tune up you will pull 10-15 degrees of timing from whatever timing you had on the foot brake. You'll also add fuel. This will move the combustion to the exhaust and start popping and banging.
If you can't get enough boost built this way, there is no hope!
If you don't care about cutting a good reaction time and don't plan on ever racing anyone at the track and just going for fun you can skip the foot brake portion and you can pull in and light both lights, grab the trans brake and have boost builder active on the trans brake and sit there until you get enough boost to launch with.
If you don't have a trans brake, you can set up the boost builder to work on the foot brake with a WOT switch. Have it pull timing and dump fuel on the foot brake only. You should still get good boost built this way. "
Good luck
07-25-2014, 08:24 AM
#4
Ive had three of the $450 PTC turbo converters.
1st was perfect but I didnt know it. It was the snowmobile one. I thought no way is that right but it was fastest with it and felt fastest on the street because as soon as you gave it half throttle it would flare way up and build boost right away. It was super tight while cruising, not sure how they do it. I highly recommend this converter, super loose with any throttle, tight when crusing. Could build as much boost as you wanted on the footbrake.
2nd, I thought the 1st was too loose, it wasnt, but I thought it was. I had them build me a tight turbo converter. I insisted on tight tight tight. Wouldnt build any boost on the footbrake. 2500 stall, terrible, I just had to have it my way. Sucked, built boost slowly driving around. The 1st converter was like a light switch because it would flare to 4800 or so with any throttle. It was felt so much faster with the 1st.
3rd, I realized my mistake with the 2nd one. I had them build me one in between. It goes to about 3700 on the foot brake and will build 7psi or so pretty easily right away.
Hindsight is 20/20 of course. The 1st "snowmobile" converter was 100% correct for a turbo car.
1st was perfect but I didnt know it. It was the snowmobile one. I thought no way is that right but it was fastest with it and felt fastest on the street because as soon as you gave it half throttle it would flare way up and build boost right away. It was super tight while cruising, not sure how they do it. I highly recommend this converter, super loose with any throttle, tight when crusing. Could build as much boost as you wanted on the footbrake.
2nd, I thought the 1st was too loose, it wasnt, but I thought it was. I had them build me a tight turbo converter. I insisted on tight tight tight. Wouldnt build any boost on the footbrake. 2500 stall, terrible, I just had to have it my way. Sucked, built boost slowly driving around. The 1st converter was like a light switch because it would flare to 4800 or so with any throttle. It was felt so much faster with the 1st.
3rd, I realized my mistake with the 2nd one. I had them build me one in between. It goes to about 3700 on the foot brake and will build 7psi or so pretty easily right away.
Hindsight is 20/20 of course. The 1st "snowmobile" converter was 100% correct for a turbo car.
07-25-2014, 11:20 AM
#5
I have a PTC converter in my car and it only stalls to about 2k on the footbrake. I have the Holley Dominator EFI in my car for the boost controller. I wasn't able to build any boost on the footbrake either until we went into the boost builder function and had it pull out all of the timing (0*) and set up the fix fuel table to 150 lbs/hr. When we set it up like that with the two step was engaged I was able to build 4#'s on dusty concrete shop floor.
Here's what I was told by others:
"You will need to wire up the two and 3 step functions. Here is what I would HIGHLY recommend. Set up one rev limiter on a WOT switch connected to your foot brake. This will allow you to hold the engine at a set RPM on the footbrake and begin to build boost.
Then set up the other rev limiter to come on when your trans brake solenoid is active.
What you will do is pull up and light the first beam. Pump your brakes really good. Hold that brake pedal down like it owes you money and go WOT. When you hit that rev limiter on the footbrake you can then slowly creep in and light the second bulb.
Once you light the second bulb grab the trans brake. You'll want the limiter on the trans brake to be 400-1000rpm higher than the one on the foot brake.
THIS is where boost builder comes in. Wire in the boost builder to only be active on the trans brake. What I do is use normal N/A timing on the foot brake to help start getting boost built. Since there is no load, even with N/A timing at 4-5-6psi of boost you will not detonate. Once you get 4-5-6psi built on the foot brake, you can transition to the trans brake. Once you grab the trans brake and the boost builder comes active, in the boost builder table in the tune up you will pull 10-15 degrees of timing from whatever timing you had on the foot brake. You'll also add fuel. This will move the combustion to the exhaust and start popping and banging.
If you can't get enough boost built this way, there is no hope!
If you don't care about cutting a good reaction time and don't plan on ever racing anyone at the track and just going for fun you can skip the foot brake portion and you can pull in and light both lights, grab the trans brake and have boost builder active on the trans brake and sit there until you get enough boost to launch with.
If you don't have a trans brake, you can set up the boost builder to work on the foot brake with a WOT switch. Have it pull timing and dump fuel on the foot brake only. You should still get good boost built this way. "
Good luck
Here's what I was told by others:
"You will need to wire up the two and 3 step functions. Here is what I would HIGHLY recommend. Set up one rev limiter on a WOT switch connected to your foot brake. This will allow you to hold the engine at a set RPM on the footbrake and begin to build boost.
Then set up the other rev limiter to come on when your trans brake solenoid is active.
What you will do is pull up and light the first beam. Pump your brakes really good. Hold that brake pedal down like it owes you money and go WOT. When you hit that rev limiter on the footbrake you can then slowly creep in and light the second bulb.
Once you light the second bulb grab the trans brake. You'll want the limiter on the trans brake to be 400-1000rpm higher than the one on the foot brake.
THIS is where boost builder comes in. Wire in the boost builder to only be active on the trans brake. What I do is use normal N/A timing on the foot brake to help start getting boost built. Since there is no load, even with N/A timing at 4-5-6psi of boost you will not detonate. Once you get 4-5-6psi built on the foot brake, you can transition to the trans brake. Once you grab the trans brake and the boost builder comes active, in the boost builder table in the tune up you will pull 10-15 degrees of timing from whatever timing you had on the foot brake. You'll also add fuel. This will move the combustion to the exhaust and start popping and banging.
If you can't get enough boost built this way, there is no hope!
If you don't care about cutting a good reaction time and don't plan on ever racing anyone at the track and just going for fun you can skip the foot brake portion and you can pull in and light both lights, grab the trans brake and have boost builder active on the trans brake and sit there until you get enough boost to launch with.
If you don't have a trans brake, you can set up the boost builder to work on the foot brake with a WOT switch. Have it pull timing and dump fuel on the foot brake only. You should still get good boost built this way. "
Good luck
So you transition from a footbrake to a t-brake? Do you think your engine would build boost on a transbrake alone? Maybe I should dive in and get the boost controller working...be much easier than changing converters or adding a t-brake.
07-25-2014, 11:24 AM
#6
Ive had three of the $450 PTC turbo converters.
1st was perfect but I didnt know it. It was the snowmobile one. I thought no way is that right but it was fastest with it and felt fastest on the street because as soon as you gave it half throttle it would flare way up and build boost right away. It was super tight while cruising, not sure how they do it. I highly recommend this converter, super loose with any throttle, tight when crusing. Could build as much boost as you wanted on the footbrake.
2nd, I thought the 1st was too loose, it wasnt, but I thought it was. I had them build me a tight turbo converter. I insisted on tight tight tight. Wouldnt build any boost on the footbrake. 2500 stall, terrible, I just had to have it my way. Sucked, built boost slowly driving around. The 1st converter was like a light switch because it would flare to 4800 or so with any throttle. It was felt so much faster with the 1st.
3rd, I realized my mistake with the 2nd one. I had them build me one in between. It goes to about 3700 on the foot brake and will build 7psi or so pretty easily right away.
Hindsight is 20/20 of course. The 1st "snowmobile" converter was 100% correct for a turbo car.
1st was perfect but I didnt know it. It was the snowmobile one. I thought no way is that right but it was fastest with it and felt fastest on the street because as soon as you gave it half throttle it would flare way up and build boost right away. It was super tight while cruising, not sure how they do it. I highly recommend this converter, super loose with any throttle, tight when crusing. Could build as much boost as you wanted on the footbrake.
2nd, I thought the 1st was too loose, it wasnt, but I thought it was. I had them build me a tight turbo converter. I insisted on tight tight tight. Wouldnt build any boost on the footbrake. 2500 stall, terrible, I just had to have it my way. Sucked, built boost slowly driving around. The 1st converter was like a light switch because it would flare to 4800 or so with any throttle. It was felt so much faster with the 1st.
3rd, I realized my mistake with the 2nd one. I had them build me one in between. It goes to about 3700 on the foot brake and will build 7psi or so pretty easily right away.
Hindsight is 20/20 of course. The 1st "snowmobile" converter was 100% correct for a turbo car.
Trending Topics
07-25-2014, 03:57 PM
#9
You have to play with the tune also, Just like tires, some like a 5 sec 5000 rpm burn and others might be a 3 sec 3000 rpm burn, Some cars like rich A/F, low timing, others high timing lean A/F. Mine being an LT, makes boost off the line with a lean A/F and moderate timing, If I richen it up, it falls on its face off the line..
07-26-2014, 02:40 PM
#10
You have to play with the tune also, Just like tires, some like a 5 sec 5000 rpm burn and others might be a 3 sec 3000 rpm burn, Some cars like rich A/F, low timing, others high timing lean A/F. Mine being an LT, makes boost off the line with a lean A/F and moderate timing, If I richen it up, it falls on its face off the line..
07-27-2014, 04:26 PM
#13
Crazy idea would a 6.0L do better off the line with boost I figure it would make the converter looser and it would bring boost in sooner because it's a bigger motor. Ultimately it would actually be cheaper for me to put a 6.0 in there I rather than buy a torque converter or having aTransbrake installed after I sell the 5.3
