Controling Turbo Boost--protecting Turbos

[Jonny Hotnuts]

One of the neat features of the AMS unit is its adjustable ramp rates between boost levels. You can set it to change from between boost increases at shifts over (X) number of seconds. Example: 1st gear set at 10psi and 2nd gear at 20psi....but after you shift into second, ramp of 6 seconds (*or any amount set) ramps the boost over the 6 seconds before reaching the next level. This keeps the sudden boost increase from blowing the tires away.

ALSO....

It has a trigger input that if applied will decrease boost to any set level. While I dont know if anyone has ever used this feature in the manor I am speaking of, it would be very easy to have EGT or AFR 'redline' limits set that trigger the 'reduce' boost trigger. It could be a very cool way to save an engine.

~JH

[SPARKY]

JH,  As I study all this stuff that "trigger" to reduce bost is what I am thinking about activating by a gearchange "trigger" signal

[Grant Borman]

Its not really common to run a wastegate or bov just to control turbine speed for the sake of the turbo.  If your turbo is properly sized for your application you will be in the turbo's efficiency island and turbo speed won't be an issue.  Once you get way out of the island your compressor temps get very high and you are at more of a risk of detonating IMO.  What kind of boost are you aiming for, whats your engine size and turbo?

To control the boost that the engine gets you will use a wastegate with a signal from the intake manifold.  You can adjust the wastegate preload to control the boost or you can run some sort of a manual or electronic boost controller to "fool" the wastegagte by augmenting the signal. I work for a road racing team thats sponsored by turbosmart and we didn't like their electronic boost controller so we use an hks setup instead.  Just make sure the solenoid is protected form heat!

Have you ever used one of those boat winches with the hand crank?  You turning the crank is almost like the exhaust turning the turbine wheel and pulling the cable is like the compressor compressing air.  When the throttle closes the exhaust velocity goes way down and its like letting go of the handle and it unwinding.  If you can grab it without hurting yourself thats like you cracking the throttle back open. Now imagine the turbo doing this dance at 100,000 rpm while riding on a thin film of oil.  Over 10,000's of shifts this will degrade the bearing journals or the shaft depending on what kind of resonance is going on.  A bov is almost like that little one way catch that prevents this from happening.  On a race car i would install one close to the compressor outlet but i would not loose sleep if it wasn't there. You might want to experiment with different spring pressures to see how it affects your boost delivery. 

[SPARKY]

I have a pair of BW S400S010 part # 169012

 from what I THINK I have been able to find out they have
64 ind and 91 exd in the compressor side
84 ind and 74 exd in the turbine side

509 BBC target hp 1450 + or - 100 should take around 22 PSI at B'ville on a hot day

[Grant Borman]

Borgwarner does have a "matchbot" on their website that you can use to validate the size of your turbos.  Twin 74mm inducers will leave you with alot of room to grow and i would not worry about over spinning them but thats just me.  The match bot should show you this. 

I bet it will sound great!

[SPARKY]

Grant----WOW  this is the site I have been needing---I am sure my head is going to SPIN and HURT  but I will have a much better feel for what we need to start with..

[TNTHEMIENGINES]

Sparky, I thought the purpose behind a turbo, supercharger, blower etc. was to make boost, not bleed or vent it! There is a lot of good info in the proceeding 3 pages, but if you switch fuels you will not need any of it. It's called Diesel. The D record is open and the E record is only 4 MPH faster than my E/DT record.

[SPARKY]

oh no you don't----don't try that with me---lol

Grant---thanks again for that site heads up

Caution!!!  Put "BorgWarner MatchBot" in your search eng.
I will put your head to spinning aand hurting---I spent about 4.0 hrs last night on it to watch the tutorials and work the the TEDIOUS adjustments---I will watch the turorials again and see if I can duplicte what I came up with last night!  This SITE will give you a much greater understanding of the trade offs---WOW 

Thanks again Grant for the heads up!  This agin points our the incredible value of this WEBSITE!! 

Thanks Jon A and SSS

[Stainless1]

There is a lot of good info in the proceeding 3 pages, but if you switch fuels you will not need any of it. It's called Diesel. The D record is open and the E record is only 4 MPH faster than my E/DT record.

still looking for a diesel lakester class 
where it would run has records in all classes.
or are you thinking he should cover the wheels 
 

[SPARKY]

Well,  READ the introduction to Borg Warners Model system.

 hardly anyone understands it--- smaller numbers can actually be larger turbos  because----part of it is a % of  the  cold side Exducer  ---ie the inner wheel 
According to B/W's  Turbodriven.com MatchBot, it look like that what fits my eng real well is a part number 177287

It has a 80 MM inducer with a 110 exducer on the cold side
and a 96 inducer with a 88 exducer within a 1.32 A/R exhaust housing--these turbos will work well for where we are looking this year and will allow some room to grow.

This is close to the surge on the left but stays with in the right hand side and does not get choked or overspeed.  Of course the "price of tea in china" just went up---lol

[Richard 2]

Garret also has a good web site. Use the turbo tech pull down tab.

http://www.turbobygarrett.com/turbobygarrett/

[SPARKY]

We went with a pair  B/W 171702s --- they have 75mm ind--100mm exd.  and 96mm Ind--87mmEx wheels in the Turbine with a 1.32 AR housing---these should be very flexiable in the 1200-1800 hp range with eng size range from 365 to 522

Next up,  wastegates:
 does anyone have experience with any of the el cheapo chi comm stuff that is working pretty good??

[LandSpeed-DSM]

I have heard its hit and miss with ebay/china gates.

But of all the places to have a questionable part.. failure leading to overboost seems to be enough incentive for me to spring for a pair of the v-band TiAl units.

Your mileage may vary!

[Tman]

Its not really common to run a wastegate or bov just to control turbine speed for the sake of the turbo.  If your turbo is properly sized for your application you will be in the turbo's efficiency island and turbo speed won't be an issue.  Once you get way out of the island your compressor temps get very high and you are at more of a risk of detonating IMO.  What kind of boost are you aiming for, whats your engine size and turbo?

To control the boost that the engine gets you will use a wastegate with a signal from the intake manifold.  You can adjust the wastegate preload to control the boost or you can run some sort of a manual or electronic boost controller to "fool" the wastegagte by augmenting the signal. I work for a road racing team thats sponsored by turbosmart and we didn't like their electronic boost controller so we use an hks setup instead.  Just make sure the solenoid is protected form heat!Have you ever used one of those boat winches with the hand crank?  You turning the crank is almost like the exhaust turning the turbine wheel and pulling the cable is like the compressor compressing air.  When the throttle closes the exhaust velocity goes way down and its like letting go of the handle and it unwinding.  If you can grab it without hurting yourself thats like you cracking the throttle back open. Now imagine the turbo doing this dance at 100,000 rpm while riding on a thin film of oil.  Over 10,000's of shifts this will degrade the bearing journals or the shaft depending on what kind of resonance is going on.  A bov is almost like that little one way catch that prevents this from happening.  On a race car i would install one close to the compressor outlet but i would not loose sleep if it wasn't there. You might want to experiment with different spring pressures to see how it affects your boost delivery. 

Thanks! The part I hilighted in orange answered one of my questions I posted yesterday!

[aut0m4tic]

Sparky:
  I have been using an el cheapo chi comm wastegate from fleabay with great success.  A friend also has had great success.  They are "jdm sport" and seem to hold up just fine.  Keep in,mind this is a 4cyl honda and 4cyl vw not 1200 hp big cid v8 so ymmv.    Many stock recirc valves will work as a blow off valve also.
  Sorry, edited because of a mistype.
  Cory