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[RESOLVED] BW s256 boost issues!

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keltalon

Supporting VIP
3,476
966
Jun 29, 2003
Luthersville Ga, Atlanta, Georgia
Well guys as you know in a recent post entitle “My new dyno number” I put down some very nice hp and tq curves and this was done using a home made td05 20g turbo. I was so excited about those numbers I was convinced that a turbo upgrade would get me into the 400hp club for sure. So I purchased a Borg Warner s256 extended tip 49lbs/min turbo for this seemed, out of all my research to be the best choice for me. I installed it on the car and now I am having issues. First issue is the turbo spools very slow full boost about 5000 rpm. Second when it boosts it spike to 26 psi and drops very quickly to 20 psi according to boost gauge. Third the turbo is rated at 49lbs/min I am only seeing about 34 to 35lbs/min. here are some things that I have noticed. First gear pull boosts no more than 20psi. Second gear pull boost no more than 20 psi. Third gear pull boost gets to around 26 psi and quickly drops to 20 psi. Fourth gear pull boost gets to 26 psi and drops slowly to 20 psi. Another thing to note is that my karmen readings seems to flatten out about 2100hz. Here are some things I have tried already.

· Boost leak test and fixed them all. The system was pressure tested and holds 35psi very steady.
· Adjusted the wastgate rod as far as it will go. I can barely pull the actuator with pliers, after the adjustment, to get it back on the waste gate. So it has ton of tension on it. Infact when I pressure test the system and watch the waste gate is start to move about 40 psi.
· I even ran the car with the actuator disconnected and nothing changed.
· I even created a boost leak in the system, drove it down the road to see if the kHz reading would increase considering that the turbo now has to spin faster therefore sucking in more air from the mas. The kHz or karman reading did not increase which leads me to believe that the problem is that the turbo refuse to spin faster.
· I disconnected my down pipe to see if it made a difference nothing still the same.
· Next move is to rip the turbo off and send it back to bullseye power for inspection because something is definitely wrong. Before I do this please offer you suggestions as to what else can be done on my part. Thanks

My mod list
Hks 264 in 264 ex
EvoIII ex manifold
EvoIII 02 housing
Dsmlink v2
Aem uego wideband
Ross pistons/eagle rods
3” turbo back exhaust
Lightly ported head
Lightweight flywheel
Custom fmic short route piping
Stock intake manifold.

I will post a log when I figure out how to get it off my laptop!
 
If I'm not mistaken, the S256 is rated for 56 lbs/min. You can't really expect to see those numbers at 20 PSI or wherever your boost seems to settle at.

Boost spike is to be expected with the internal gate, mine does the same thing as well as creep a little in the upper RPMs. The price you have to pay for the convenience, I suppose. Are you sure you're not putting so much tension on it that its response is a little delayed? Basically you just want it to keep the flapper closed, it doesn't have to gorilla-grip it closed. I'm more inclined to blame your MBC for not allowing you to boost past 26 PSI than anything else.

I'm not sure what to say about your spool times, except maybe exhaust leaks. Mine consistently spikes past full boost a bit after 4000 RPM. Anyway, get that log out ASAP.
 
If I'm not mistaken, the S256 is rated for 56 lbs/min. You can't really expect to see those numbers at 20 PSI or wherever your boost seems to settle at.

Boost spike is to be expected with the internal gate, mine does the same thing as well as creep a little in the upper RPMs. The price you have to pay for the convenience, I suppose. Are you sure you're not putting so much tension on it that its response is a little delayed? Basically you just want it to keep the flapper closed, it doesn't have to gorilla-grip it closed. I'm more inclined to blame your MBC for not allowing you to boost past 26 PSI than anything else.

I'm not sure what to say about your spool times, except maybe exhaust leaks. Mine consistently spikes past full boost a bit after 4000 RPM. Anyway, get that log out ASAP.

thanks guy. what i was doing with the wastegate is to ensure that it indeed was not opening. trust me i am not new to turbo performance, i have been doing this for a long time and this is the most puzzling thing i have ever ran across. i will get those logs up asap!:thumb:
 
any pre-turbo exhaust leaks? also what vac source is going to the actuator? anything T'd from that source?

but I would consider an external wastegate, I refuse to use an internal wastegate for this size of turbo.
 
problem fixed thanks to fellow dsmer;) stock rubber turbo intake pipe was the !@#$$% culprit. I am not going into a lot of detail but it would let the turbo bring in the air. now the turbo shines like it suppose to. so next i need to do some tuning. we cut to rubber section and put it closer to the turbo with a custom made pipe and the car seem 29lbs boost and drops to 25 by redline. so i just ordered the 4" pipe from FP. thanks again everybody who offered a suggestion:cool:
 
My buddy has this turbo in his 1g with a stock motor, sheetmetal, fp2s and 20 psi off the tial spring (no boost controller). He just raped a c6 z06 with intake, exhaust and maybe cam(s) by 3 cars 2 weeks in a row. I also witnessed him hang with a gsxr750 out of the hole and all the way to 130-140 ish.

This turbo KICKS ass, definitely impressed with it. Glad you got yours fixed, enjoy.
 
My buddy has this turbo in his 1g with a stock motor, sheetmetal, fp2s and 20 psi off the tial spring (no boost controller). He just raped a c6 z06 with intake, exhaust and maybe cam(s) by 3 cars 2 weeks in a row. I also witnessed him hang with a gsxr750 out of the hole and all the way to 130-140 ish.

This turbo KICKS ass, definitely impressed with it. Glad you got yours fixed, enjoy.

Yeah I did a lot of research on various turbos before puchasing one, the s256 impressed me the most. Its good to here the potential of the turbo. when the fp pipe comes in next week the tuning can begin.
 
problem fixed thanks to fellow dsmer;) :


You should buy that guy over from dsmtalk a beer ^ LOL

The extended tip s256 is the turbo I plan on running when I upgrade from my e316g. Im really interested in your results once you start really pushing it.
Everything else looks good so far! What was your previous turbos before the BW, I know you had a 20g and 16g; what is your impressions/ comparisons on this turbo between those two. Like the power band, the way it hits, spool, driving characteristics on the streets ?
 
You should buy that guy over from dsmtalk a beer ^ LOL

The extended tip s256 is the turbo I plan on running when I upgrade from my e316g. Im really interested in your results once you start really pushing it.
Everything else looks good so far! What was your previous turbos before the BW, I know you had a 20g and 16g; what is your impressions/ comparisons on this turbo between those two. Like the power band, the way it hits, spool, driving characteristics on the streets ?

No problem!! I have owned mostly stock turbos 13g, 14b ect.. But the two upgrades that I went with the evo III 16g was a very hard hitting, tire spinning monster. It just did not give me what I needed in the upper rpm, considering I am front wheel drive and running hks 264 intake and exhaust cams. I kick a lot of butt on the street with the evo III mostly stock srt 4s and stock wrx sti, stock evo's and a ton of Hondas! I was neck and neck with a lot of svt cobras and c5 corvettes. I knew I need something with a little more heat! So I upgraded the evo III 16g to a td05 20g. Spool was almost the same maybe 200rpm but in the upper rpm the thing hit like a monster! Trust me the turbo was scary! As far as the borge Warner s256 in concerned I have not been able to really push it yet therefore I will give you my take on it next week;)

dyno with

evoIII 317hp
20g 356hp
bw s256 ?
 
All this hype. I cant wait till mine gets here!!!!ROFLROFLROFL im like a little kid waiting on ups like he was santa

kind of funny you say this. I could not wait for ups to deliver mine either! So I made arrangents to pick the turbo up from the driver that morning at the ups loading center. I told them that it:sneaky: was urgent that i get the package.
 
No problem!! I have owned mostly stock turbos 13g, 14b ect.. But the two upgrades that I went with the evo III 16g was a very hard hitting, tire spinning monster. It just did not give me what I needed in the upper rpm, considering I am front wheel drive and running hks 264 intake and exhaust cams. I kick a lot of butt on the street with the evo III mostly stock srt 4s and stock wrx sti, stock evo's and a ton of Hondas! I was neck and neck with a lot of svt cobras and c5 corvettes. I knew I need something with a little more heat! So I upgraded the evo III 16g to a td05 20g. Spool was almost the same maybe 200rpm but in the upper rpm the thing hit like a monster! Trust me the turbo was scary! As far as the borge Warner s256 in concerned I have not been able to really push it yet therefore I will give you my take on it next week;)

dyno with

evoIII 317hp
20g 356hp
bw s256 ?

Let me know how it goes with the new bw s256. When you tune. Looking foward to compare your results and mine. Im going to run e-85 soon though Going to see how far i can push my 1000cc . i have been running a 80-20 mix with it so far on my fp red was running 28psi 0 knock 11-1 afr on the wideband. IDCs were at 76% so there was alot left in the car. My Red took a dump about 3weeks ago so ive been searching for a good street/strip turbo. The red was great but just to laggy for me man when it hit though it hit hard. Everything ive read on the s256 is been great. When i first read your thread i was a little discourage cause it would have been the first thread i have read about the turbo being bad, glad you figured it out:thumb: My friend has a green on his car and we going to go head to head at same boost level. green vs s256 we shall see. The ett should give me the upper hand. I will post up results of that.
 
Let me know how it goes with the new bw s256. When you tune. Looking foward to compare your results and mine. Im going to run e-85 soon though Going to see how far i can push my 1000cc . i have been running a 80-20 mix with it so far on my fp red was running 28psi 0 knock 11-1 afr on the wideband. IDCs were at 76% so there was alot left in the car. My Red took a dump about 3weeks ago so ive been searching for a good street/strip turbo. The red was great but just to laggy for me man when it hit though it hit hard. Everything ive read on the s256 is been great. When i first read your thread i was a little discourage cause it would have been the first thread i have read about the turbo being bad, glad you figured it out:thumb: My friend has a green on his car and we going to go head to head at same boost level. green vs s256 we shall see. The ett should give me the upper hand. I will post up results of that.

I will keep you posted!!! I will say this a fellow dsmer and myself when trying to figure out what the problem was took the turbo pipe off to see if the turbo was really spinning freely the thing spun like a ball bearing unit what I mean is we watched it spin for 30 seconds or more after the engine was turned off. My buddy is the one that brought it to my attention and I quote "that thing is still spinning are you sure its not a ball bearing unit" after he said this I just laugh!
 
No problem!! I have owned mostly stock turbos 13g, 14b ect.. But the two upgrades that I went with the evo III 16g was a very hard hitting, tire spinning monster. It just did not give me what I needed in the upper rpm, considering I am front wheel drive and running hks 264 intake and exhaust cams. I kick a lot of butt on the street with the evo III mostly stock srt 4s and stock wrx sti, stock evo's and a ton of Hondas! I was neck and neck with a lot of svt cobras and c5 corvettes. I knew I need something with a little more heat! So I upgraded the evo III 16g to a td05 20g. Spool was almost the same maybe 200rpm but in the upper rpm the thing hit like a monster! Trust me the turbo was scary! As far as the borge Warner s256 in concerned I have not been able to really push it yet therefore I will give you my take on it next week;)

dyno with

evoIII 317hp
20g 356hp
bw s256 ?

That awesome. I like your 20g numbers and from what you say about the spool, sounds like a perfect street turbo.
And ill give you my address so you kno were to send the beer :p

Anyways keep us updated, if you end this thread saying you blew both your tires off from all the torque steer then I will definitly be getting this turbo :sneaky:
 
That awesome. I like your 20g numbers and from what you say about the spool, sounds like a perfect street turbo.
And ill give you my address so you kno were to send the beer :p

Anyways keep us updated, if you end this thread saying you blew both your tires off from all the torque steer then I will definitly be getting this turbo :sneaky:[/QUOTE

well i am sceduled to go to the dyno friday. I am just as excited as everybody else about what the turbo will actually lay down hp wise. i did a log today, after removing my fmic, taking it to the welding shop and welding a massive break at one of the welds on the endtank. when my wideband, at WOT, kept dropping to 10.1 afr i knew i had a boost leak somewhere. so it is fixed now. i just did a log @ 16psi and everything look perfect. i wanted to turn the boost up but i couldn't because i left my mbc on top of the car and lost it somewhere on the road. so i guess i will be ordering another one of them sometime tonight. but on a good note i logged the best untuned run i have ever seen on my setup or any setup i have ever had to this day! i had to connect a vacuum line from the bov to the wastegate because the boost guage went to 35+ psi very quickly. so i think at this point all my boost issues has been settled. dsmlionk recorded 308 hp @ 15psi of boost and right at 2000hz of air. i will post the log tonight sometime. so right now we are waiting on the mbc and fp 4" turbo intake pipe and off to the dyno we go.:sneaky: i will keep this thread updated as new infomation comes in!;)
 
By what rpm are you seeing that 15psi? How does it feel? Does the turbo whistle alot louder? I have heard that bw turbos are alot louder:thumb:

turbo is not that bad when it comes to the sound. honestly the rpm move so fast i really cant tell where i am seeing those psi. but it seems as if the car is making full boost around 4000 rpm. I will post the log so you guys can see really what is going on as far as boost, speed, ect! just keep in mind that the log i will post is a log that is not tuned what so ever:)
 
turbo is not that bad when it comes to the sound. honestly the rpm move so fast i really cant tell where i am seeing those psi. but it seems as if the car is making full boost around 4000 rpm. I will post the log so you guys can see really what is going on as far as boost, speed, ect! just keep in mind that the log i will post is a log that is not tuned what so ever:)

Do a spool test in 4th and then 5th gear and start at about 2k and just floor it.
It will accelerate so slow at that point that you will be able to get within 200rpms visually of were you achieve full boost.
Doing it in 1st, 2nd, and for you, 3rd gear will be much too difficult to measure that.
Try that and get back to me. Whenever your running 25psi plus id definitly like to see spool times then even more.... Im hitting 25psi at 3300 rpm w/ my evo3 16g in 5th gear; id like to make a comparison to how quick this thing gets going.
 
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