Turbo systems for X1/9's

Discussion in 'Discussion Forum' started by Dr.Jeff, Jun 22, 2018.

  1. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    EDIT: This thread started out talking about air flow and a intercooler. But it has grown as there is a lot more really great turbo related information to be learned from our members. So I changed the title and want to open up the discussion to any/all things relating to a turbo on a X1/9.


    In another thread discussing "cold air intakes" the subject of reducing engine inlet air temps is being discussed:
    https://xwebforums.com/forum/index.php?threads/cold-air-intake.34637/

    This led to a few of us talking about intercoolers to cool the intake air on turbocharged engines. I want to continue that topic here so we don't divert so far from the original thread.

    Please refer back to page 4 of the referenced thread to see the background discussion up to this point. And please continue to contribute here.
     
    Last edited: Jun 26, 2018
    myronx19 likes this.
  2. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    I've read a couple articles on measuring the efficiency of a intercooler, what are good temperature goals for an IC, etc. There are a lot of factors to consider. Using the turbo from the UT we are looking at low boost systems, and a small turbo with not a lot of air volume. So the intake air temp (IAT) won't get as high as it would with larger systems and higher boost levels. But a general goal of trying to get the IAT as close to ambient temp seems good. Naturally that also depends on what levels of ambient temp you are dealing with. In a freezing climate it won't be necessary (nor really desirable) to get the IAT that low. But in a scorching desert it would be nice to go below ambient (impossible without external chilling).

    I guess like everything there are other considerations. Reducing flow restrictions throughout the entire system will decrease back-pressure and reduce temps significantly. Things like pipe diameter/length/routing, intake manifold design, head port/valve efficiency, etc. are all important. Im my opinion some of these items are beyond the cost limits of my project, and frankly even beyond the limitations of the engine's design. So I'm focusing on the items that I can easily improve. I'm using 2-1/2" (63mm) connecting pipes, a very large/low restriction air filter with 3" (76mm) inlet pipe, a larger intercooler core with tapered end tanks, a layout with as direct and short as possible routing, mild porting of both manifolds and the turbo, a fabricated turbo outlet manifold and downpipe, and a mildly upgraded cam. I also intend to do a little mild clean-up work on the head's ports, but I really do not have the proper facilities to correctly port it or the funds to go with big valves, etc.

    Also there are physical limitations to deal with making some compromises necessary. As mentioned I will use the trunk for added room, open up the engine bay as much as possible, add fans and air ducting, and rearrange things. But there will still be a few things that are less than ideal. Welcome to the real world.

    I'd like to hear what others have done or plan to do to help with temperature management. What have you found that works, or doesn't work? Some design ideas to work around the restrictions posed by the X? Solutions to turbo specific issues with this application?
     
  3. lookforjoe

    lookforjoe True Classic

    This is a pretty good article :

    http://www.gnttype.org/techarea/turbo/intercooler.html

    Getting the 'approach' as close to ambient is the ideal - as you mention above. IC construction (fin count / density / internal divertors, etc.) all play a big part in getting optimum performance out of the intercooler setup. Cheap eBay IC is not a viable option, IMO.

    eBay_________________________________Treadstone
    [​IMG]

    The modern factory intercoolers, even though they have plastic tanks, can be very efficient. At least, the manufacturer that Volvo uses from about 2014 on are. Good fin design & density, internal diverters, and used on 500WHP builds in EU.

    I used Treadstone Performance on my last Volvo, after dicking around with a range of cheap eBay (CXracing, etc) IC's.
    [​IMG]

    3" IC plumbing. Some articles discuss minimizing bends, etc. I never found it made one iota of difference. I went through at least 5-6 plumbing variants.

    [​IMG]

    For my current Volvo, I bit the bullet & had Bell make me one to spec.

    [​IMG]
     
    Last edited: Jun 23, 2018
    dllubin likes this.
  4. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Looks great.

    For the small displacement of the SOHC, and the tiny size of the UT turbo, I think it could be counter productive to use too large of intercooler and plumbing. As I understand performance will fall off if the volume is too big for the amount of air flowing through it. At the very least more lag would result. So I struggled a little when deciding what to get.

    But in my case I've limited my budget for the whole project, knowing there will be trade offs as a result. I believe the outcome will be improved over stock but not earth shaking. However my goals are to keep it very drivable, reliable, and not require a lot of major modifications to the engine. Basically something of a conservative design the factory might do. As it is there will be a lot of various modifications all around the engine bay just to fit everything. I can't imagine what would happen if it was a no holds barred super build.
     
  5. speedy fiat

    speedy fiat Daily Driver

    Location:
    United Kingdom
    I went down the route of a charge cooler (water cooled intercooler) plumbed into a small rad at the front of the car. Water pumped around by a bosch pump commonly found on car heater systems. I must admit that this was put together without much knowledge but it seems to work. It essential to have a temperature probe in the inlet system as otherwise its all guess work. The standard fan on the rad can just about slowly draw down the inlet temperature while stationery, but when I'm racing the temperature falls away very quickly to around 35-40c. Unfortunately I dont have a temp probe before the cooler but you can imagine the temp as it exits a turbo being worked hard, obviously ambient temperature has a say in this, i was in 20c. Restarting after a short break could easily see 60c air inlet temps. The cooler the better but I'm told above 50 degrees celsius is definitely to be avoided. One other potential advantage of a charge cooler is much shorter inlet pipework, drawback is all the water pipe plumbing.
     
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  6. Mxgrds

    Mxgrds True Classic

    Location:
    Netherlands
    05B62AA1-A959-43A8-BAA7-829468EE7801.jpeg D94DCF40-DCC6-4942-817D-B0330D4C25E4.jpeg

    This is my standard ut setup. Blue is the area were the inlet air comes from. That easily 20c cooler than under the hood.
    Yellow shows the standard ut ic. There is a cool box between side panel and ic. The air from the side scope is directed in there. On the otherside of the ic is the fan. The fan draws the cool air from the cool box through the ic. The fan is controlled with a sensor on the cool side of the ic. (Picture 2). Placed outside. When crossing 40c the fan is turned on. To late probably, but the best i could do.
    The wires you see, are temp sensors to measure the cooling capacity of the ic.

    A first test on a normal drive (fan not switched on) the temperature is cooled 7c.
     
    Dr.Jeff likes this.
  7. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Thanks for sharing your results, sounds good. Have we seen pictures of your set up?

    When I started researching things for my project I was left with the impression a water to air intercooler was not the way to go for a street car. The reason had to do with heat soak; they are more efficient (reduce temps more) initially but with extended driving that falls off dramatically. However since then I've seen a lot of info to contradict that. So I guess either method can be good, I'm sure there are a lot of factors involved; the water pump's circulation capacity, the size/location of the air cooler, the plumbing, etc. Ultimately I went with a air to air for simplicity, but I won't know how well it works until everything is built.
     
  8. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Thanks for the extra details. You are way ahead of me, I did not realize you have already done everything I suggested previously. Nicely done.

    I keep seeing lots of various info on what are safe levels for temps, what systems to run, what not to do, etc. I guess what's important is if it works for you. In the bigger picture street turbo systems are still somewhat new and continuously developing. Yes, they've been around forever but not to the the extent we've seen in recent years. And with that growth comes experience and learning. That's what makes this a fun project for me. Several years ago I considered building a turbo project (non-Fiat car). But after doing some research I decided it simply wasn't safe or reliable for a street car. More recently that seems to be changing.
     
  9. speedy fiat

    speedy fiat Daily Driver

    Location:
    United Kingdom
    I'll post some pictures once the car comes back from the garage - the more you expect from an engine the more systems it needs to keep it together . I've never had any problem with extended street driving and the inlet temps creeping up. Charge cooler systems that can not keep the temps down I would suggest are not designed right (although I caveat that statement by saying I'm a complete amateur at this) after all engine manufactures decided many years ago that water cooling is generally better at controlling temperatures.
    One point to note on the inlet pipework is that silicone hoses are very good insulators compared to aluminium ducting. Also if you are trying squeze the very last bit of performance then silicone hoses will bulge under pressure adding to the turbo lag
     
  10. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    I'd agree. Same for air to air coolers for that matter.
    Looking forward to some pics and details of your set-up. The next major task for my project will be to choose the engine management ECU. Lots of good choices on the market these days, each having its benefits and deficits.
     
  11. Mxgrds

    Mxgrds True Classic

    Location:
    Netherlands
    77E1E234-BB6A-40EB-B11D-E7D69D174A05.jpeg As i have on the left side a box in which the side scoop is venting, i was suprised that even in that box the temperature rises. My theory is, although i can not proof it, is that under the hood the warm air is held up raising the air pressure a bit. The raised air pressure prevent free flow of cool air through the side scoops into the engine compartment. For that reason i now think that letting the warm air escape is probably more efficient than getting cool air in. So, today i opened up the hood by placing some busses between the two layers to get wider air vents.
     
  12. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    There have been a number of members that completely removed the inner layer of the engine cover ("rain tray"), allowing the vent slats to be fully open. I don't know if that is practical with the weather conditions in the Netherlands? For my build I will be removing the engine cover completely and replacing it with a mesh grill (open weave screen). That will be partially necessary to allow room for the top mounted intercooler (making the cover taller), but will also provide maximum ventilation of the hot air as you described. However the climate in this part of the world isn't a factor; no rain/snow to deal with.

    In a couple other threads we have discussed the general flow of air through the engine bay. Air coming from under the car, in through the side scoops, through the engine cover, etc. In those discussions there have been some reports of various temp measurements and simple air flow observations that seem to indicate there really isn't a lot of flow around the engine bay. Relatively little passes through the side scoops. The air from under the car isn't as cool as we might think. And the engine cover does not vent that much (like you said). So basically the engine bay has little air flow and gets really hot.

    Based on all this I think I'll try several modifications to see how much it can be improved. In addition to the grill replacing the engine cover, I want to enlarge the side scoops and associated openings to the bay, and open the rear panels between the engine bay and the rear trunk as well as the rear trunk and the rear taillight panel (another grill there). The vertical panel below the rear trunk (across the rear suspension crossmember, in front of the exhaust) has already been removed to clear the turbo's custom downpipe/exhaust system. I haven't decided about the trunk floor; being horizontal I don't think removing it will improve rear exiting of the engine bay's hot air much. But it is the only panel on the car that has a little rust so it might come out anyway.
    Some ducting/shielding plus insulation materials will also be added within the bay to help separate the hot and cool air regions. And a couple electric fans placed at critical locations. I am also relocating the air filter/intake outside of the engine compartment in hopes of finding a little cooler air.
    Not sure what more can be done, but certainly open to ideas.
     
  13. Mxgrds

    Mxgrds True Classic

    Location:
    Netherlands
    I have to admit that allthough I try to figur out what the best setup is for keeping it cool, I have actually not a cooling problem. And i don’t want to sacrifies the useability by removing the rain tray (yes in the Netherlands there is plenty of rain) or using the trunk for something else than bagage. The biggest risk for overheating is to get trapped in a traffic jam on hot weather after a firm highway drive. There will be no cooling from air passing through the engine compartment.
     
  14. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    That makes sense. The climate there is much cooler overall, and wetter than where I am.

    For my project I only consider this as a car for occasional fun drives. I won't be taking it on any trips or driving it regularly. So it does not bother me to sacrifice some useability. However it won't be a track car either. The boost levels will be kept quite low and everything conservative for reliability. So I'm keeping a full interior and even air conditioning. I know that sounds odd to put a turbo on a car with air conditioning. But the weather here is very severe heat and AC is mandatory. The turbo is intended to help overcome the loss from the AC, and hopefully make it more enjoyable to drive (stock it seems very anemic to me). It was that or a engine swap, but that was too ambitious for me. :)
     
  15. Mxgrds

    Mxgrds True Classic

    Location:
    Netherlands
    The stock ut already gives a major boost as compared to a 1500 injection. With a simple bleed valve even more.

    Oh. You want to put the ic horizontally under the engine lid without rain tray. For the outgoing air, that sounds good. But from where comes the cool air to cool it? If you use the trunk, you can move the cooling overflow tank to it. That will make some space for a fan and an air tunnel.
     
  16. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    That's basically the layout; the coolant overflow and a couple other things going into the trunk to open up space in the engine bay, the IC flat over the area between the rear wall of the cabin/intake manifold/left strut tower/fuel filler area (i.e. above the trans), no AFM (aftermarket ECU) and air filter in the trunk (direct to turbo inlet). The IC is too big to fit down into the space by the trans (where yours is) so it will be by the items listed, putting it a little above the height of the stock engine lid. Some ducting and a strong electric fan (Spal) on the IC to get cool air across it, like you said with the space opened below. Another fan in the trunk to draw hot air out the opened panels and through the back (open taillight panel). Hopefully that takes turbo heat away from the rest of the engine. A bit more to it but that should give the idea. Eventually I can take some pictures but for now I'm still fabricating things.

    Fortunately my smaller workshop is air conditioned so I can do some work during the summer months. Unfortunately however, it is too small to put the car inside it. I use it for fabrication projects, small parts rebuilding, etc. So last night I put together a new exhaust flange for the turbo's exit (replaces the stock UT cast housing). This bolts to the turbo where the exhaust turbine dumps out and the internal wastegate opens (first pic below). On the stock cast part (UT) these are basically combined into one open chamber, then routed straight down. For my 1500 application I wanted it to aim about 45 degrees rearward so the downpipe can be a direct straight path through the gap between the rear-suspension cross-member and the trunk floor (where the stock exhaust pipe passes on some versions of X). That panel has been opened up so lots of room for the downpipe/exhaust. I also wanted to try and separate the two ports from the turbo's turbine and wastegate to improve flow. Then merge them gradually a little further down the pipe. I was limited at how much that could be accomplished but I think it is a bit better than stock.

    Turbo exhaust turbine exit and wastegate (still need to do a little porting to these):
    001.JPG

    Started with a pattern from the turbo and a piece of steel plate (not using stainless to make it easier to do, more on that later):
    002.JPG

    A few cuts to the plate:
    003.JPG

    Then started attaching the tubes (some welding/clean up left to do yet):
    004.JPG
    007.JPG

    Ideally I'd like to have used a more gradual bend starting a little further away from the flange but the AC compressor is right there, so had to compromise. This is still a smoother radius than the stock one. Also these tubes are considerably larger diameter than the stock ones. According to what I've learned, separating the two exhaust paths (turbine and wastegate) at their exit points will significantly improve flow rates...kind of a mini-header I guess.
    It's difficult to tell from this, but the tube is positioned to aim back toward the rear of the car, just under the trunk floor. The "downpipe" from here will connect directly to a flex joint, small muffler, and the tip (have a neat stainless tip that should look great coming out the center of the rear panel). The turbo should muffle things enough that a straight-through muffler will be good. This way everything is a direct shot from the turbo flange all the way to the tip at the back. Should be decent exhaust flow, just hope it isn't too loud.
     
    Last edited: Jun 25, 2018
  17. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Regarding choice of materials for the exhaust flange. Originally I planned to use all stainless steel for all exhaust components. But the exhaust expert I buy my supplies from said that isn't preferred, that it's better to use mild steel for the flange and stainless for the pipes, muffler, etc. Has to do with temps and warpage I guess. According to him the only reasons to use SS are for longevity (if ceramic coating is not to be used), and for looks. He has decades of experience and builds the systems for many high-end shops, so I trust his opinion. Plus that made it possible for me to do all the work myself without having to send things out for cutting, etc. (ever try to cut a thick SS plate like this?). The 90 degree tubes shown in the above photos are also mild steel. Honestly I wasn't 100% sure of the design so this was intended to only be a mock-up test piece. But frankly I'm very pleased with how it came out so I might just use it and not remake it in SS...we'll see if I can sleep tonight. The flex joint, muffler, remaining tubes, and tip are all SS. I will be ceramic coating everything (inside and out) after it is all done. Additional insulation, heat shields, etc are also on the list. Unfortunately the only part that will show is the polished tip.

    By using larger tubing on the entire exhaust, some mild porting of the exhaust manifold (stock UT cast-iron unit) and turbo housings, much larger intake tube and air filter, and larger IC and tubes, combined with aftermarket wastegate actuator (adjustable and ECU controlled) and BOV (also adjustable), the system should work well for the relatively low boost levels intended. I want it to spool quickly, offer plenty of torque, and not generate a ton of backpressure heat rather than give maximum top end; strictly a street car/normal road use so drivability is the goal.
     
  18. mkmini

    mkmini True Classic

    Location:
    Latvia
    Looks very clean :)
     
  19. Mxgrds

    Mxgrds True Classic

    Location:
    Netherlands
    Looks very good. The opposite of my project. I use stock components and try to optimize them, you produce optimized parts yourself. Great hobby, isn’t it?
     
    Dr.Jeff likes this.
  20. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Originally I intended to use all stock UT components for simplicity and reliability. Frankly that would have been much easier. But I found that some UT items I don't have are very difficult to get here (some are even difficult to find in Europe). And some items just would not work well adapting the UT system to my 1500 X engine (they are similar but not identical). So I realized to keep everything stock would not be practical nor realistic. Once the decision was made to go aftermarket with some key components, a lot of the plan changed. And it has kind of snowballed. But this is my first experience with a turbo build and I'm enjoying learning as I go. It will be interesting to see how it all works when done (if I ever get there).

    After finishing up the welds on that turbo outlet flange/downpipe I did a quick mock up of the exhaust system to double check how everything is fitting. It's looking good but it will be very tight lengthwise; the muffler and tip will just fit in a straight configuration between the turbo and the rear grill, but I won't be able to add the flex joint as I'd hoped. Therefore I'll have to come up with a good method of hanging the exhaust so it is well supported but still has room to move with the engine.
     
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