SFI 25.2 Mustang/LSx build "The Renegade"
06-27-2008, 03:14 PM
#824
NO good testing from the track today, the first pass off the trailer the car went 6.0 @ 125 on 5# of boost since we forgot to turn the BC on. Every pass after that it blew the tires. Temps were in the upper 90s with track surface @ 145. It was slick.
06-28-2008, 03:16 AM
#828
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nice meeting you today phil. you should have stayed for the race. 1st rd of qualifying the track came around and was incredible. another new record by vrettos. 7.37, he took us out in the semis. i was to gun shy. after 6 wasted passes during the rental i was way to soft on the car. the track was there but i didn't get crazy with it for fear of another wasted pass. we still did go 7.87 at 178 soft as ****. only had a 1.35 60' a far cry from normal but it's my fault. i shouldve thrown some power to it. then again nothing i couldv'e done would have let the backup motor run with vrettos.
06-28-2008, 04:38 AM
#830
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Co2 Boost Control: In order to understand why Co2 boost control is needed in some applications, basic knowledge of how a wastegate and boost controller works is needed.
An external wastegate has a diaphragm which creates a seal, and a spring which holds the wastegate closed. Spring rates vary depending on the amount of boost you want to run. Typically they are given in a "bar" value. For example, 1 bar would be 14.7psi. This would mean that in order to open the wastegate you would need to exert a greater pressure than the 14.7 psi spring holding the wastegate closed. In order for the wastegate to work you must have the boost reference port hooked up to the compressor side of the turbo or intake manifold. If you don't have this vacuum line attached then the boost pressure will not be limited to the set spring pressure; it will build unlimited boost pressure until your engine is destroyed (“bottom” wastegate port). Normally, exhaust manifold pressure pushes against the valve and diaphragm (through the vacuum line attached to the compressor reference port) which in turn pushes against the wastegate spring. When the exhaust manifold pressure exceeds the spring pressure the wastegate’s plunger opens releasing the excess pressure through the wastegate outlet (typically via a dumptube).
The top port on the wastegate is normally open to the atmosphere. This provides no additional resistance to the wastegate “spring”, and the wastegate will operate at the desired spring pressure. In order to increase the amount of boost over the spring pressure inside the wastegate, two methods can be used.
The first method is using a manual boost controller. A manual boost controller works using a spring and check ball. By screwing the adjusting screw into the boost controller you put more pressure on the spring which reduces the amount of airflow through the boost controller and into the boost controller port (“bottom” wastegate port). Less airflow means less pressure will be assisting the spring to keep the wastegate plunger shut. The “top” port is left open to the atmosphere with a manual boost controller.
The second method is using an “electronic” type boost controller. An electronic boost controller uses a solenoid inline of the boost pressure source to the top port on the wastegate. The solenoid is “pulsed” by a PWM (pulse width modulated) output from the boost controller or engine management system. With more opening and closing of the solenoid more pressure is applied to the wastegate. With less opening and closing, less manifold pressure is applied and less boost is achieved. When more boost pressure is applied to the top port of the wastegate, it directly applies more force to the wastegate valve, keeping the valve shut until enough exhaust pressure is applied to open the wastegate. This is essentially like adding a higher rated wastegate spring (stiffer). The bottom port of the wastegate is connected directly to the pressure source (compressor cover or intake manifold), with nothing installed inline.
Exhaust pressure increases as boost pressure increases. The amount of exhaust pressure in the exhaust manifold is affected by the turbo exhaust wheel size, exhaust housing size, exhaust manifold type (equal length or log), displacement, cam profiles, etc. In most situations using a manual boost controller you are not able to increase boost much more than a 2:1 ratio, meaning if you are running a 10psi wastegate spring you are not able to increase the boost much more than 20psi. With an equal length manifold, and large turbo sometimes a 3:1 ratio can be achieved. When using an electronic boost solenoid on the top port of the wastegate, as much as 6:1 ratio can be achieved if an equal length manifold and large turbo are used. For high boost applications, using a small wastegate spring for lower gear traction an electronic boost controller is what is necessary. For most turbo set-ups (probably 95% of what is on the market) achieving a 6:1 ratio is not possible. This is where running a compressed gas that can apply greater than manifold pressure is necessary. For example, a 3psi wastegate spring can be used, and flowing 90psi of co2 pressure to the top port of the wastegate will allow for greater than a 6:1 ratio. This gives the ability to get the boost low enough to aid in traction, and increase boost to pressures in excess of 50psi if needed. The boost solenoid vents the excess Co2 pressure so that target pressure can be reached. This also allows for more boost consistency with elevation change, as you are not relying on less available atmospheric pressure for the turbo compressor to work with. Boost controllers such as the AMS-1000 or AMS-500, and the AEM boost controller solenoid being used with the AEM EMS or Hondata systems are compatible with Co2. It should be noted that Co2 as a pressure source is not practical for a daily driver, and should really only be used for drag racing applications.
so basically it allows you to run LOWER boost with a big spring to aid in traction? and then ramp in the boost.
Chad
06-28-2008, 12:03 PM
#831
nice meeting you today phil. you should have stayed for the race. 1st rd of qualifying the track came around and was incredible. another new record by vrettos. 7.37, he took us out in the semis. i was to gun shy. after 6 wasted passes during the rental i was way to soft on the car. the track was there but i didn't get crazy with it for fear of another wasted pass. we still did go 7.87 at 178 soft as ****. only had a 1.35 60' a far cry from normal but it's my fault. i shouldve thrown some power to it. then again nothing i couldv'e done would have let the backup motor run with vrettos.
We're going to make a converter change, correct the rear suspension issues and check out the brakes, they would push through and the line lock didnt seem to hold the car. We will break down the car sunday and fix everything. Great news is the converter is a 15 minute process to change.
Phil
06-28-2008, 01:54 PM
#832
We didn't end up racing last night and its a good reason. We found a couple of changes that need to be made to the car, one of which is a pretty big change. We ended up working with the car for 3 hours to get it to scale correctly but created a bigger issue so that needs to be fixed. My chassis guy said if we had made a clean it we probably would have put the car into the wall.
Anyways we made 5 hits yesterday and got one clean pass. With 4.5psi the car went 6.0 @ 125 in the 1/8. With 4.5psi the car makes roughly 650hp at the tires. We managed a 1.58 60' leaving soft. Once we can get the car to leave on boost we should see some 5.60s @ 4.5psi.
If the track was in better shape we would have leaned on it. We've got over 1200 more hp once we can get the car to 60'. We're shooting for low 1.30s high 1.20s in the 60'.
Things we need to address:
We think last week we glazed the pads, we tried to stop the car after a 165mph pass and at the top end you could really tell the brakes were hating life. We noticed that the linelock would not hold the brakes enough to do a burnout so we had to do a rolling burnout all day. I'll pull the pads sunday and check them, if glazed we'll fix and reinstall.
The Neal Chance Converter is set too tight. We need to pull the converter and adjust it so its alittle looser, hopefully letting us leave at a higher RPM/boost but hitting the tires alittle softer.
We also need to address the rear suspension/preload. We've got the changes that need to be made but need the time to put them into play.
Anyways we made 5 hits yesterday and got one clean pass. With 4.5psi the car went 6.0 @ 125 in the 1/8. With 4.5psi the car makes roughly 650hp at the tires. We managed a 1.58 60' leaving soft. Once we can get the car to leave on boost we should see some 5.60s @ 4.5psi.
If the track was in better shape we would have leaned on it. We've got over 1200 more hp once we can get the car to 60'. We're shooting for low 1.30s high 1.20s in the 60'.
Things we need to address:
We think last week we glazed the pads, we tried to stop the car after a 165mph pass and at the top end you could really tell the brakes were hating life. We noticed that the linelock would not hold the brakes enough to do a burnout so we had to do a rolling burnout all day. I'll pull the pads sunday and check them, if glazed we'll fix and reinstall.
The Neal Chance Converter is set too tight. We need to pull the converter and adjust it so its alittle looser, hopefully letting us leave at a higher RPM/boost but hitting the tires alittle softer.
We also need to address the rear suspension/preload. We've got the changes that need to be made but need the time to put them into play.
06-28-2008, 05:23 PM
#833
We didn't end up racing last night and its a good reason. We found a couple of changes that need to be made to the car, one of which is a pretty big change. We ended up working with the car for 3 hours to get it to scale correctly but created a bigger issue so that needs to be fixed. My chassis guy said if we had made a clean it we probably would have put the car into the wall.
Anyways we made 5 hits yesterday and got one clean pass. With 4.5psi the car went 6.0 @ 125 in the 1/8. With 4.5psi the car makes roughly 650hp at the tires. We managed a 1.58 60' leaving soft. Once we can get the car to leave on boost we should see some 5.60s @ 4.5psi.
If the track was in better shape we would have leaned on it. We've got over 1200 more hp once we can get the car to 60'. We're shooting for low 1.30s high 1.20s in the 60'.
Things we need to address:
We think last week we glazed the pads, we tried to stop the car after a 165mph pass and at the top end you could really tell the brakes were hating life. We noticed that the linelock would not hold the brakes enough to do a burnout so we had to do a rolling burnout all day. I'll pull the pads sunday and check them, if glazed we'll fix and reinstall.
The Neal Chance Converter is set too tight. We need to pull the converter and adjust it so its alittle looser, hopefully letting us leave at a higher RPM/boost but hitting the tires alittle softer.
We also need to address the rear suspension/preload. We've got the changes that need to be made but need the time to put them into play.
Anyways we made 5 hits yesterday and got one clean pass. With 4.5psi the car went 6.0 @ 125 in the 1/8. With 4.5psi the car makes roughly 650hp at the tires. We managed a 1.58 60' leaving soft. Once we can get the car to leave on boost we should see some 5.60s @ 4.5psi.
If the track was in better shape we would have leaned on it. We've got over 1200 more hp once we can get the car to 60'. We're shooting for low 1.30s high 1.20s in the 60'.
Things we need to address:
We think last week we glazed the pads, we tried to stop the car after a 165mph pass and at the top end you could really tell the brakes were hating life. We noticed that the linelock would not hold the brakes enough to do a burnout so we had to do a rolling burnout all day. I'll pull the pads sunday and check them, if glazed we'll fix and reinstall.
The Neal Chance Converter is set too tight. We need to pull the converter and adjust it so its alittle looser, hopefully letting us leave at a higher RPM/boost but hitting the tires alittle softer.
We also need to address the rear suspension/preload. We've got the changes that need to be made but need the time to put them into play.
06-28-2008, 07:34 PM
#834
How are you adjusting the pre-load? Just some fyi if you didn't know, you can't do it with the upper control arms. You'll have to do it with the anti-roll bar. I had a car on a set of scales for an entire day one time trying to sort things out. All the uppers will do is put the rear suspension in a bind, and move the rearend from side to side. If the upper bars weren't at an angle, it would be a different story.
We know now that you can't. We're going to center it back up and set pinion angle to straighten that out. Once we get the rear back to square one we will try again at setting preload.... Did hear a couple of different ways to set preload without scales over the weekend.
06-29-2008, 11:21 AM
#835
With you IN the car, loosen the upper control arm bolts, so you can turn the bolts, use the lowers to set the wheel base, then adjust the pinion and center the rear end, if there is no preload you'll be able to turn the bolts up top, set it up with you in the car.
With you IN the car have the right side of the anti roll bar link loose, then adjust the right side link until the bolt slides in and out easy on the right side, that would be zero preload. Then I would lengthen the link 1/2 turn which will give you some preload. I think that would be a good first guess starting point. Without scales it's a little tricky. Some cars need a lot of preload, I only had like 1/4 - 1/2 turn in my last car and it was within 10 pounds from left to right weight with me in the car.
With you IN the car have the right side of the anti roll bar link loose, then adjust the right side link until the bolt slides in and out easy on the right side, that would be zero preload. Then I would lengthen the link 1/2 turn which will give you some preload. I think that would be a good first guess starting point. Without scales it's a little tricky. Some cars need a lot of preload, I only had like 1/4 - 1/2 turn in my last car and it was within 10 pounds from left to right weight with me in the car.
06-29-2008, 09:51 PM
#837
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If the track was in better shape we would have leaned on it. We've got over 1200 more hp once we can get the car to 60'. We're shooting for low 1.30s high 1.20s in the 60'.
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06-29-2008, 10:23 PM
#839
06-29-2008, 10:55 PM
#840
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Your 100% correct. Before we talked to Alex we thought it needed to be loosened up. He has the same converter down to the stator, his is full loose while mine is full tight. Couple things why we think its too tight, one we can't really build boost, any launch RPM over 3500rpm it blows the tires off. Brian said your car should be done soon and will be the car to beat!