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Discussion Starter · #1 ·
What hurdles can I expect with fitting the famed Disco Potato? Here is what I am figuring so far...

modify oil lines (water lines should be ok?)
custom MAF to turbo inlet piping
software

With the downpipe, what is the best route to go? Will any of the 3" DP's bolt right on (JT, BSR)? If not, would I be better off welding a new flange to one of these or having a whole new DP fabricated? I'd prefer to stick with an internal WG to save $$$. Is anyone on this forum running this turbo in a 9-5 Aero or in a Viggen?

Thanks!
 

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I'm running this turbo but on a 9-3 SE. Downpipe bolted right up no problems. Oil lines were a PITA.

May I ask why you are upgrading the turbo if you still have not upgraded the exhaust? I might be missing lots but this upgrade should come after intake, exhaust, IC ...........

Either way best of luck and keep us posted.
 

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Discussion Starter · #3 ·
I am gathering the necessary hardware one piece at a time (many already in my possesion) to install all at once when I can figure out how I am going to get custom software.
Stage X programs are designed to squeeze the maximum amount of power with the minimum amount of hardware modifications (Hirsch excluded) so I don't want to go this route. My goal is to have conservative software around 320hp, hopefully with the stock pistons surviving, but with hardware capable of 350hp or so. If I can keep the engine from knocking, the pistons will survive. Corky Bell said it best...thermal management is the key to any successful turbo system. I figure I will need larger injectors, 3" turbo back exhaust, race intercooler, turbo inlet pipe, throttle body delivery pipe, open intake, GT28RS turbo (possibly GT30), as well as the standard corresponding upgrades to clutch/brakes/suspension. Porting the head and more aggressive cams are in the back of my mind but I'm hoping I can get by without these along with the pistons. If there is anything else I should consider please comment. CO-Saab, which downpipe are you using?
 

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there was a thread on b235 pistons here ...

nasty over 300 as I remember and some debate whether it was detonation causing the prob or just an inherent flaw...

maptun's stage 3 includes upgraded pistons I believe...

I have the gttb30 and the lines to the turbo are flexy braided jobs..easy to fit and I would guess easy to have made up with the appropriate fittings and length
 

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Discussion Starter · #5 ·
Ylee...thanks for the input on the fittings! You have to go all the way up to a Maptun stage 5 for piston upgrading (340hp) while the stage 4 retains stock pistons (305hp). You could be right about the pistons failing even without knock. Compressive loads have to be very high at power levels over 300hp and if these compressive loads are carried into the upper rpm's and combined with high inertial loads, this could be where the failures occur. In other words, while the pistons can handle the (compressive) force of 450nm at low rpm's, when these high torque loads are carried up into the RPM's (giving high hp values) and combined with the inherently high inertial loads caused by the speed of the piston pushing and pulling itself at 6500rpm the piston reaches a point where it can no longer hold together regardless of whether there is knock or not.
 

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The B235R is just more sensitive to detonation for a couple relatively simple reasons.

1. The '99 models had exceptionally weak pistons. MY2000 and later had reinforced pistons which can be identified by the connecting rods which are trapezoidal shaped on the small ends.

2. All of the B235 engines use shorter pistons with smaller ring lands. This makes the engine run smoother (better rod ratio) and reduces emmissions. Unfortunately it makes it easier to break the pistons.

3. The B235R uses a non-forged Eutectic alloy. It's just as strong as a forged piston when cool (in some cases stronger), but it gets hot easily and loses strength. The reason for use of this alloy is that it reduces cold emmissions, and keeps combustion temperatures warm when cruising because it does not conduct as much heat to the coolant through the cyllinder walls.

The trouble with some upgrades is that they drastically increase the heat discharged into the piston. Then when it does detonate, like all Saabs do on occasion, it will break the now much weaker piston.

I would suggest water injection to combat the problem, but it's more expensive than upgraded pistons when done correctly.

The best advice is to try to make power different ways with a B235R. For instance upgraded camshafts, tubular exhaust manifolds, intercoolers, and upgraded intake manifolds can all boost power without heating up the piston much. They'd all need to be custom tuned into the ECU though.

A larger diameter, slower spooling exhaust turbine will reduce backpressure at high RPM and reduce the chance for piston failure.

In the end I'd just suggest picking up some forged pistons and getting them ceramic coated. It will keep them stronger, and keep your mileage intact by not allowing the very good conducting forged alloy to suck all the heat out of your combustion chamber when cruising.

Dubbya~
 

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Also, if you do put new pistons in a B235R make sure to get the sides moly coated or your mileage will suffer slightly. The stock pistons are moly coated on the sides, and hard anodized on the tops. They're good pistons, just not designed for 300+ hp.

Also do not attempt to ceramic coat a set of stock pistons. The ceramic coating will not hold on to the hard anodized upper surfaces.

Also, 9000 Aero pistons will not fit. However, you may be able to use Aero pistons if you also swap to 9000 Aero connecting rods. This may adversely affect the engine ballance though, and the engine will feel considerably less responsive.

Dubbya~
 

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The gathering knowledge at the moment indicates that you never get the gains you hope for from simply swapping out physical components- unless you can take your car, with all it's mods, to the software developers who can then specifically map it to your requirements.

IMO, if you want to upgrade the turbo, you would be best speaking to your intended tuner and taking their recommendation on which unit they would use. This way you also stand a good chance of getting the software right as well. Otherwise you can spend more money than you need to and not get as much gain as you hoped for.
 

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XAAMOTTOMAAX,

I am using the BSR Stainless downpipe. I might have read this wrong, but are you saying you are going to gather all the hardware and install when a custom software tune is available? From personal experience I would not recommend this route. You should install hardware in parts so you know if any single component has a problem. You can install exhaust, intake, intercooler, any other piping you deem necessary and the turbo prior to tune time. (Caution on the turbo, it might spool to fast if using BB) Then at tune time add the injectors and have the tuner "go to town." All I'm saying is you don't want to throw everything on the car at once, it makes troubleshooting a PITA.

Keep it shiny side up!
 

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I can concurr co-saab
I threw everything at my saab and its taken me about 8 months (so far) to sort it out
I think it will be a bit longer too...
 

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Discussion Starter · #11 ·
Good tip on doing things in steps! I will definately use your experience to my benefit in this regard as my original plan was to do exactly what you advise against. Adrian good info on the pistons. I agree with the method of tuning mentioned (cams, headers, water injection) but there are some pitfalls with the ever-finnicky T7 system. Water injection in this instance is something I plan to avoid. I have heard nasty stories of sorting out boost as the water mucks up the ion sensing. I have also heard tube headers can muck up boost control by creating a poor WG flow. "The exhaust pulses just pass the small WG port." I think with proper thermal management I can keep the temps down. This would include ceramic coating the turbo inlet pipe, throttle body delivery pipe, downpipe, exhaust, possibly the outside of the stock exhaust manifold. Of course the intercooler is a key part of the equation as well as opening the intake by removing the stock air box and installing a cone filter. The turbo selected is also a very effecient design. Spooling too fast is an interesting problem I had not considered. Mark you are spot on with the need for proper software. I am still trying to sort out how to get the software however. I would be glad to have any of the repuatble tuners tweek the software for me but I do not wish to work with one tuner for the entire project or to purchase all of the hardware from one place. I would prefer to organize and do as much of installation as possible while leaving the programming to the specialists. A good effecient design strategy with the proper software should make for a very entertaining yet reliable car. I truley believe the Stage X programs sacrifice reliability and strive only for maximum power with minimum hardware changes. The goal in a stage program is how much power you can generate for the least amount of money. Customers shop based on hp per dollar (or euro) with little or no consideration for reliability.
 

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Have you considered a VNT GT28RS? Garrett offer VNT on many of their new turbos, though it hasn't reached the automotive market in excess.

VNT is nice because instead of using a WasteGate to just dump excess exhaust pressure it simply moves the vanes so they point nearly straight at the turbine.

When done correctly with equal length exhaust headers the exhaust backpressure (static pressure) can actually be below the intake static pressure.

It'd be more expensive, but worth considering.

When thinking of headers generally the rule is that when using equal length headers you increase the A/R ratio of your exhaust housing. That eliminates any boost creeping problems, and because the headers are more efficient it also maintains the same spool up as the smaller housing. Also because of the larger housing your Volumetric Efficiency will be higher at the upper parts of your rev band, which is nice for producing power.

Split pulse exhaust manifolds and turbines enhance the effect of headers.

Dubbya~
 

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Discussion Starter · #13 ·
Great stuff in concept but I think at this point my plate is pretty full just getting to 300hp! I'm going to stick with the stock exhaust manifold but the pistons I really can't decide what to do. I know I should just upgrade them...the 2.3NA cams are something that would probably be a good idea as well. Any potential drawbacks with these cams in the B235R engine?
 

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Nick T runs those cams successfully. He noted that the stock software didn't seem to mind them at all.

I would reccomend also upgrading the valve springs. This is because all of the T5 engines run more lift than their T7 counterparts.

The reccomended price per valve spring is $19. Part number for T5 valve springs is: 91 29 651

The cams can be found used and reground reused, or bought new.

Intake cam part number: 91 45 657 ($299)

Exhaust cam part number: 91 45 665 ($475)

Obviously that means it would be cheaper to get them custom ground from some place like Paeco.com. They regrind to custom specs for about $210 a cam. Just in case you can't find any N/A cams. Also the B234R cams are also pretty good, they'll show a little improvement over the B235R cams. They might be easier to find as well.

The specs for various Saab camshafts can be found here: http://www.sacsaabs.org/faq.htm#Cam%20Profiles

edit: The B234i and B234R cams will cause slightly slower spool up, you may want to try them out before making a finite decision on the headers. You might find that the headers help get spool up back to where it should be as well as accentuating the top end of the naturally aspirated camshafts.

Dubbya~
 

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Originally posted by ylee coyote:
[qb]I can concurr co-saab
I threw everything at my saab and its taken me about 8 months (so far) to sort it out  
I think it will be a bit longer too...    [/qb][/b]
You and me both, I'm over a year and still not in top shape, everyday. I’m guessing a few more months till I'm done as well. I have the luxury of a hand tune by Frank Stromqvist in the near future. If you don’t know, it’s a long story.

Originally posted by XAAMOTTOMAAX:
[qb]I think with proper thermal management I can keep the temps down.  This would include ceramic coating the turbo inlet pipe, throttle body delivery pipe, downpipe, exhaust, possibly the outside of the stock exhaust manifold. [/qb][/b]
XAAMOTTOMAAX, I'm not sure you want to hear this but I have done all of the above. Checkout my Site. I noticed the above put my EGT's through the roof. I've seen nearly 1100°C. The parts are contributing less radiant heat than otherwise, but it sure keeps those EGT’s high.

Depending on where you live getting one of the tuner to visit for a hand tune is possible.
 

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Discussion Starter · #16 ·
CO this is the kind of stuff I DEFINATELY want to hear! If I have something in mind and actuality would reveal something different, having your experience and willingness to share is invaluable. Maybe coating the manifold and exhaust should be skipped to allow some of the heat to escape, but the coating of the intake portions would be good to prevent heat soak. Thanks for the tip! I am hoping that I can have a hand tune setup at some point just as you mentioned. I live in the DC area but I would be willing to travel a good distance for this. The project can not be completed without this. How did you arrange the hand tune with SQR? I emailed Engstrom about this but never got a reply.
 

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Discussion Starter · #17 ·
Caution on the turbo, it might spool to fast if using BB  [/b]
CO, is your turbo not the BB variety? I thought all GTR series are BB turbos. When you bought yours, how did you specify the exhaust outlet to get the correct fit to the DP? I have only seen these for sale with the 5 bolt oval shape covering the WG.
 

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Originally posted by XAAMOTTOMAAX:
[qb]Maybe coating the manifold and exhaust should be skipped to allow some of the heat to escape, but the coating of the intake portions would be good to prevent heat soak.[/qb][/b]
I’m not sure I agree. I was only cautioning you on the results. The EGT’s will be higher than if you didn’t coat, but this is by design. The high EGT’s are healthy in this setup, keeps the exhaust flowing quickly. As long as they don’t creep back into the block your golden. You know why you’re having high temps as opposed to just having high temps and being concerned the turbo is working to hard. On that note my turbo remains ~ cool as the exhaust piping has not turned into a large heat sink radiating that heat back into the turbo. Let me get my car tuned & running properly and I’ll have better info to base my opinion.
Originally posted by XAAMOTTOMAAX:
[qb]I live in the DC area but I would be willing to travel a good distance for this.  The project can not be completed without this [/qb][/b]
Depending on your time frames, this can be arranged. SQR visits the U.S. a few times a year and you could coordinate with Frank’s schedule. He was in the Boston area a few months ago. Getting this coordinated is a royal PITA and will probably take ~ year. Stay in touch with Bo and he’ll keep you informed as to possible dates. It would probably help to order something from him, so he knows your business is serious. I also understand other tuners have made the voyage for various reasons.
Originally posted by XAAMOTTOMAAX:
[qb]CO, is your turbo not the BB variety?  I thought all GTR series are BB turbos. [/qb][/b]
Yes mine is BB, that’s how I know you’ll likely run into problems with the spool.
Originally posted by XAAMOTTOMAAX:
[qb]When you bought yours, how did you specify the exhaust outlet to get the correct fit to the DP?  [/qb][/b]
I got lucky with this as well. Turbo Engineering Corporation is right down the street from me. They were able to assist. Very knowledgeable but condescending, I wouldn’t use their services again. This might be the part you should order from Engstorm to save hassle?

A thought I had on your setup this morning, you might want to consider getting two ECU tunes. If your hardware will support 380 HP but you only want 320 HP for everyday driving, might be a good idea to get a tune for both. I plan on doing this as I feel ++300 HP for the winter here is a bit much.

More questions keep them coming. Someone else has to be using this turbo, are you out there????????
 

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Discussion Starter · #19 ·
CO what problems have you experienced with spooling too fast? What are some potential problems you might not have seen? Do you have to take it easy on the throttle because of this?
 

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Originally posted by XAAMOTTOMAAX:
[qb]CO what problems have you experienced with spooling too fast?  What are some potential problems you might not have seen?[/qb][/b]
Very few. I was using this turbo on the stock ECU for awhile (and bits in-between) and had the car buck violently a few times on WOT. Luckily the stock ECU still limits RPM's to ~6200 so it wouldn't easily over spin itself. In this regard I was not the guinea pig. Most tuners know of the problem and have properly addressed it in their program. My boost gauge jumps up and then settles and then jumps again and begins to slip back. Spool to fast in not really the problem. The problem is once you get up in the rev band. The turbo was spinning so fast down low that by the time you start to near/break 7000RPM, the turbo is hitting 200,000 RPM.

Originally posted by XAAMOTTOMAAX:
[qb]Do you have to take it easy on the throttle because of this?[/qb][/b]
Ha, you got the wrong man here. I never take it easy on the throttle! One of the benefits of living out west, wide open roads w/ a posted speed limit of 75 MPH. Just hash'n you bro. My car is so unreliable at this time that I don't drive it much. It's only seen ~4000 miles in the last year and 1800 of those were one weekend. I abuse every toy I touch. I'd rather break it and find a problem than not use full potential.


Similar discussion somewhere else on the net. I'm not sure if the 9-5 is the same way but getting this thing to fit is not easy. I have added some pictures to demonstrate this on page three of my site. Basically the intake is difficult on a 9-3.
 
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