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Anyone tried Turbo conversion of the 360..?

Discussion in '360/430' started by Moby Dick, May 2, 2004.

  1. Moby Dick

    Moby Dick Rookie

    Jan 12, 2004
    41
    Anyone tried to convert their 360 to into a turbo-car?
    All you need to do, is strip the engine down and replace the pistons with new Mahle forged low-compression pistons.They are also lighter than the originals. You then need a couple of slightly modified T04's and a custom exhaust-system.Maybe with a pop-off valve.

    You should get about 600bhp@7200rpm. 3,3 sec. 0-60 and a top speed of 210mph.

    Ok, not a job for the average garage-weekend.

    ("Ahh...finally, finished waxing the car, maybe i'll just drop in some new pistons and a couple of turbo's while it dries"):D:D:D
     
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  3. Andrewgavi

    Andrewgavi Guest

    I thought for a turbo conv' one would need more that just turbos and changing the pistons, and maybe just more than a pop-off valve, also who makes a turbo system?
     
  4. Moby Dick

    Moby Dick Rookie

    Jan 12, 2004
    41
    I know that Koenig makes one, the one i mentioned....
    You can see the result here....:)
     
  5. PWehmer

    PWehmer Formula 3

    Oct 15, 2002
    1,733
    Surrounded by Water
    A recent Forza article reviewed a german company who does a supercharged 360.

    They stated the heat problems in the 360 engine compartment were compounded with turbos. The turbo itself does put off some good heat.

    If you used a water cooled intercooler like Norwood uses on the 348 conversions that would keep a lot of heat out of the bay.
    The supercharged convesion used water cooled intercoolers also.
     
  6. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,832
    The twilight zone
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    The Butcher
    Agreed. Definitely an aftermarket ECU, bigger fuel injectors and fuel pump. I think the stock cams have an awful lot of duration for a street turbo, it will be very hard (read impossible) to make any boost below about 4500 rpm without changing them. New or modified headers are probably a must, a water/air intercooler (with it's own water pump and a heat exchanger mounted up front), rearrange or replace the air filter/air inlet plumbing, plumbing from the turbos into the intake manifolds to include a blowoff valve. Now your done. Norwood would be the place to call, would expect the job to run north of $30K.

    I’d figure about the same for a good supercharger as well. I think superchargers are nicer on a street car than a turbo because most of the boost is available right from idle and lag does not exist. You wouldn’t need to change the cams either, so the engine would feel exactly like it does now, only with a lot more hp. A screw type compressor would be the way to go. That is what I have on my 308 and it really makes nice smooth power. I run it at 22 pis boost and I think it’s about 600 hp, I should have it on a dyno in a couple week. Ford just put the same supercharger I am using on the GT, I think they are running it around 15 psi. I don’t like centrifugal superchargers like Novitec (sp?) – the German company- uses, like a turbo they do not make boost in the bottom ½ of the rpm band.
     
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  8. 348 Turbo

    348 Turbo Formula 3

    Jul 17, 2002
    1,837
    good post. BTW- Norwoods hasn't yet turbo'd a 360. I'd guess they'd want to do a good study on it first to work out as many bugs as possible. I asked about it last time I was there, and James said he'd really like to do one, but no one had put their car up to be the experiment.
     
  9. Moby Dick

    Moby Dick Rookie

    Jan 12, 2004
    41
    Informative answer, thanks...:)

    What about going for the bi-turbo configuration, to get a broader rpm-band..?
    Bi-turbo is a small turbo feeding a larger one, like on the RX-7. I already have a mildly tuned supercharged car (230SLK). It's not more than 245hp (from it's original 197). The carachteristics of the s.charger is nice on the street, but you will get smoked on a track.And you can't adjust the charging-pressure on the s.charger.
     
  10. boondocksts

    boondocksts Rookie

    Apr 30, 2004
    26
    SW USA
  11. astjr

    astjr Karting

    Feb 13, 2004
    97
    Does anyone know how much a 360 gearbox can take???
     
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  13. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,832
    The twilight zone
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    Sequentail turbos doesn't really help much and complicates the system and adds weight. The absolute best you can do wifth a turbo is to start making a little boost at about 1/3 of redline and full boost by 1/2 redline, but that would be a very low boost system, like 5 psi. At 15 psi full boost is about 3/5 redline. It's just how it works out, turbines/centifugal compressors don't have a very big turn down ratio, no where near a positive displacement system (like a piston engine).

    Screw type superchargers can be tuned to pretty high boost. I run mine at 22 psi, so the stock 235 hp goes up to about 600. The boost is adjusted by changing the pulley on the blower or crank, it takes about 15 minutes. But the truth is that I never adjust it, it's alway on high :) The old logic that you need a turbo at the track died when screw type compressors were invented. Turbos still can't be beaten on a road race track, but a screw type superchaerger comes very very close. Autocrossing like I prefer, ther is simple no way a turbo car will compete with a supercharged car.

    Centrifugal compressors, very bad in my opinion. The give you all the worst features of turbocharging and supercharging all in one package.

    It's at least as strong as a 308/328 box which handles 800 hp without any problem according to Jim at Norwood. It's the clutch that alway is the first to go, plan on replacing that.
     
  14. FrostCS

    FrostCS Karting

    Mar 3, 2004
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    Christopher
    This is a very common misconception. The Turbo system you are describing is a "Compound" turbo system primarily used in high pressure situations (mainly diesels).

    The term bi-turbo simply means that, bi, or "twin"; it has little to do with the design of the induction system.

    The RX-7 actually uses a "sequential" turbo system, and not a compound turbo system as stated, a sequential system directs exhaust gases to spool one turbo at a time, and the intake of the first turbo is not fed into the other turbo (that would be a compound system). I am including a little passage of rx7 turbo information as to what the sequential system does.
    "The Sequential Twin Turbo system optimizes the forced induction effect throughout the speed range by operating one turbo at low revs and both turbo's at high speed. Only the primary turbo is activated at low speed, enabling it to respond more quickly and effectively, while at high speed, both turbo's function, resulting in a smooth delivery of power.
    At low speed, the exhaust passage that leads to the secondary turbo is closed by a valve, thus, only the primary turbo is operating. As the engine speed and load rise and the exhaust gas volume increases, a portion of the gas is directed towards the secondary turbo via a pre-spinning control valve to prepare it for full operation. Various parameters such as engine load, throttle opening and atmospheric pressure are calculated by a computer, which then determines the optimum moment to open the switching valve, thus allowing the secondary turbo to start providing full boost."

    There is much to go over and study before implimenting a forced induction system on a normally aspirated car. You already discussed the ignition, fuel already so I will not bore you with that. But the main discussion everyone goes through is "Turbo or Supercharger". Now, I have done a 'little' research in the past on both.

    You can argue that a Turbo was known for producing a lot of heat, but with newer turbochargers heat isn't as much an issue, as it used to be. Sure you will want to use an intercooler, but most superchargers you will need to do the same also. You can argue about lag, control, response, pretty much all day long; but with today's technologies neither really matter. If you were wanted to use turbo(s) on the 360, the biggest concern would probably be losing the glass top, or at worst getting a vented top (such as the F40 uses).

    Superchargers also produce heat, and can be much harder to choose one than your generic turbo. Centrifugal type superchargers produce as much, if not more heat then modern turbo's since they don't have the amount of cooling, and lubrication. Thus, these are not the best choice for a rear engined car with cooling difficulties. Roots/Screw type superchargers are a bit cooler running, but it would be difficult to cool these if you wanted anyways, since they use the plenum as a means of a surge chamber.
    Yet, one of the best designs of a supercharger (compressor) ever designed was done by Wankel. You never hear too much about these sc's, but you see them more then you think. Mercedes uses a Wankel type SC, as well as volvo, and Toyota used them on the old mr2's. All of those superchargers(Wankel type) are built and sold through a Japanese company, "Ogura Clutch Co.". With these superchargers, you have the choice of placing them where you want, they are compact, and they don't need intercooling for low boost, but of course it would be recommended if they are placed in a high heat area.
    I'm not here to advertise for them though, I just figured I'd toss it into the list. You can however control boost much easier on the turbo's but the supercharger is also able to alter boost over a small range using a by-pass valve.

    Your choices for adding FI to the 360 will probably limit you to either well matched turbo's with coolant lines (though no hybrid turbos!) or either a roots/Ogura SC. With low boost, you shouldn't need to replace the pistons; though I am unsure about the strength of the rods. Fuel and Ignition and Intake cam tuning being the main time consumers.

    Then there is intercooling, while water might be good for the track for a run or two at the drag strip, it is extremely inefficient today. Only used to save space for cars not often used, not raced, or not run. Anyone who tries to sell you a water-cooling setup for a street and track car is selling you a load of bull. A typical air-water intercooler will run around 60% efficency, where as a air-air will be closer to 75%. Yes the air does take up more space, but they are closer then you think when you get done with the added weight, tanks, and plumbing from the air-water system. Your best bet for constant temperatures and cooling will be the air to air intercooler. "Heat Soak" problems with air-air intercoolers are a result of improper end-tank construction or lack of ventilation (a thin fan will help greatly with mid-engined cars).

    "Low End" torque is never a problem with a proper turbos, or an good supercharger (ie roots/screw/rotary(wankle)). Your only concern in the 360 might be the intake cam, it isn't designed for use in an FI'ed engine, thus the valve overlap might be a bit harsh.

    I'm not sure about the transmission, you will be going through clutches a lot faster on F1 gearboxes, but other then that I can't comment.

    At the end of the day when all is said and done, you will have to do a lot of work, and spend a lot of money on the conversion, for a good bit of hp increase. Was it worth it? Well, that's up to you.
    Just remember, while a Centrifugal Supercharger, and a Turbocharger might look a lot a like, they are extremely different in more ways then one. But Supercharger or Turbocharger, they both are indisputably the best power suppliers ever.
    Never Say Never,
    CS
    I said too much.
     
  15. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    The heat issue with turbos is as real todady as ever. It is caused by the amount of surface area exposed to both the hot exhaust and the engine bay. There are some good isulation solution, but a turbo engine bay will alway be quite a bit hotter than a naturally aspirated or supercharged car.

    Again, heat in the engine bay is primarily form the exhaust so this is mostly untrue. Heat going into the intake charge if a function of boost pressure and compressor efficiency. A turbo or a centrifugal supercharger have the highest efficiencies , about 65%, and there the lowest temperature rise of the intake charge. A screw type compressor is close behind at 60% with a root trailing at 40%. Intercooling any of them is similar of difficulty and depends on the type of cooler you want to use and the way the parts are mounted.

    Sizing a positive displacement type supercharger (screw or root type) is a very straight forward operation. Most maker have about 4 sizes, you tell them how much hp you want and they tell which blower you need. Superchargers are much much more forgiving about being mis-sized. If it is too small, it will work great, but not deliver your target hp. If it is over size, you will have a little less flat boost curve, so instead of 2/3 boost at idle, you may be as low as 1/2 boost. Nothing you can't live with and may never notice.

    Cooling efficiency is a function of cooler size and the number stages. An air/air cooler is the simplest and only 1 stage, so it is the best choice if there is a supply of cool air available. 75-85% efficiency is about where a good well sized system will be. Higher efficiency is possible, but requires an impractically large cooler. In a midengine car, there is normally no supply of cool air, so it starts to make sense to look at water/air systems even though they are more complicated. A water/air system has 2 stages where each stage should be about 85-95% efficient, making the system at worst .85x.85 = 72% or as high as 90%, so they are work just as well, but are heavier and harder to make. The advantages are you can mount the heat exchangers up front where threre is plenty of cool air available and there is less volume in the intake system which improves throttle response and reduces lag.

    several principles of thermodynamics make it impossible to make "low end" torque with a turbo, a positive displacement supercharger is the only way that can be accomplished.
     
  16. Moby Dick

    Moby Dick Rookie

    Jan 12, 2004
    41
    Some very informative info here, but i'm a bit confused...:(

    I'll guess that the Wankel-type SC, is the same as a twin-screw positive displacement SC. Because that is the same type i have in my Mercedes. I know it as a Eaton/Lysholm-type. On my MB the pulley is changed for a bigger one on the crank-wheel. The air filter and exhaust are modified as well.
    But the total gain in hp, is not more than 38.

    I think that what is refered to as a sequential turbo configuration sounds good. But also rather complex. But you get a good gain in hp and torque across a wide rpm-range. But i can see the problems with keeping it all cool.

    But how much power can the F1 gearbox handle..? If the 360 is super or turbocharged to the 600hp+ region, maybe a Quaife or a Xtrac gearbox is a good investment..?
     
  17. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,832
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    I have never seen aWankle-type SC, although I guess one could be built. Ogura builds roots type blowers
    http://www.oguraclutch.co.jp/english/e_products/sc/sc_gaiyou.htm
    MB, as you said is using lysholm, which is a screw type blower. It is athe same type blower I am running on my car and I can assure you that they can produce well over 20 psi of boost. I don't know why MB would be running it as low as they are, but it could be turned up quite a bit if it is not already at redline. The blower is good to 13000 rpm without oil lines or 15000 with oil lines. So measure the diameters of you pulley and max blower rpm is Engine redline x Crank pulley diameter / blower pulley diameter.

    It adds some, but not a lot to the width of the power band...say 500 or just maybe 800 rpm. After that you run into physics again, there just isn't much energy is a slow moving exhaust.

    I wouldn't worry a bit about the trans, it's the clutch that will fail. I use a tilton carbon-carbon in my car.
     
  18. FrostCS

    FrostCS Karting

    Mar 3, 2004
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    Christopher
    The Ogura SC line is surely NOT a roots blower nor a twin-screw. http://www.wankel-ag.de/amd_e.html
    AMG and Carlsson (Mercedes Tuners) both have Ogura SC's in their line up, while not completely Mercedes, they both take in a lot of sales, and work with Mercedes. (Search the MB forum if needed)

    Intercooling efficiency has nothing to do with stages, it's surface area, how much heat can be absorbed, and core design. Water can only absorb so much heat before it's saturated. Since you have a much greater volume of air available to you, it's much easier to get rid of the heat. While water, in theory is cooler then ambient air, the water temps soon rise, and then that theory is useless.
    I am leaving some links for those interested in intercooler tech/information, both links have very good FAQ and information resources:
    http://www.bellintercoolers.com/
    http://www.are.com.au/index.htm

    The heat arguement never was referred to as engine bay temps, since there is dozens of ways to remove air quickly from the engine bay anyway. It referred to the core intake charge temperatures, they used to argue turbochargers raised intake charge temperatures much higher then superchargers, this is no longer the case; as I stated earlier.

    A quaife, or xtrac transmission would of course quickly double the costs of adding FI to the 360. I don't beleive anyone is aware of the 360 transmission limit yet, so it would be something that requires experimenting.

    References to physics and thermodynamics are limited in this discussion, I suggest more research, there is more to exhaust pressure, and exhaust pulses then just engine rpm. When sizing and using turbo's much more comes into account then just a bunch of hot air. Even a short read on diesel tech is fundamental to why turbochargers are used, yet can be much more helpful then a common hotrod-forum.
    I hope I didn't miss anything, if I did, let me know.
    CS
     
  19. mk e

    mk e F1 World Champ

    Oct 31, 2003
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    You should send an email to Ogura and and let them know there websight is wrong, it labels their SC as a root type...and it looks like a very nice one. They seem to have done a good job dealing with the leak issues that normaly plague the roots design. It looks like a very nice piece

    Carlsson does use a Ogura
    http://www.oguraclutch.co.jp/english/e_products/sc/sc_carlsson.htm
    As does Volvo
    http://www.oguraclutch.co.jp/english/e_products/sc/sc_volvo.htm
    which sells this very nice roots type supercharger.
    http://www.oguraclutch.co.jp/english/e_products/sc/sc_gaiyou.htm

    Where to begin....intercoolers are simple heat exchangers, in normal operation they are not intended to absorb heat, they exchange it form one flow stream to another. During start up they do absorb heat, but some reach steady state and exchange heat between the streams. The amount of heat that is exchanged compared to how much is possible is the effectiveness of the heat exchanger, sometime refer to as efficiency, although this is not really correct. Any heat exchanger approaches 100% effectiveness as the surface area approaches infinity…An air/air intercooler is exchanging heat between the intake charge (heated by compression and the inefficiency of the compression) and the ambient air. In order for that to work there needs to be a supply of ambient air. There is a lot of air in the front of the car, but very little in the middle unless some type of scoop is added. As an air/air intercooler in not a very good choice unless you are willing to add scoops to the car and most ferrari owner are not. It is not practical to send the intake charge to the front of the car where there is air. So, the solution is to use 2 water/air heat exchangers, a small electric water pump and some water hose. One heat exchanger (the intercooler) is mounted in the intake charge path and passes the heat to the water. The water is pumped to the front of the car and though a second heat exchanger which passes the heat to the ambient air stream. More complicated, but much more effective than tying to cool the intake charge with the limited and heated air available in the engine bay. The system does not lose it’s effectiveness due to heat soak any more than an air/air system does.

    The heat problem with turbocharging a midengine car is the engine bay. The engine bay get heat hot even without a turbo, it can get out of control with one unless a lot of care is taken. There is simply no good way to create air flow through a mid-engine bay. Turbos raise the engine bay temperature much more than supercharging due to the extra hot exhaust pipes. Turbocharger have never , at least to my knowledge, raised the intake charge temperature more than a supercharger. Quite the opposite, that is a big part of why turbochargers make more hp than superchargers in general.

    The basic rules need to be satisfied no matter who is building the system. There is just no energy in a slow move gas stream. When low rpm boost is required superchargers are used. Diesel train engine use a supercharger in the lot, then as rpm come up and the turbos are making boost, the supercharger is disengaged using a clutch. They don’t go through that trouble because they want to, it’s because they need the power the boost delivers and they can not make it with a turbo. They also can not afford the fuel the supercharger would cause them to burn, they need the efficiency of a turbo once they leave the yard. It’s just math.

    you did
     
  20. dmcgill

    dmcgill Formula 3

    Apr 16, 2004
    1,640
    Las Vegas, NV
    Exactly what he said...whew, just avoided a repost!
     

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