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jjps13
01-31-2012, 10:40 PM
Okay fellow zilvians, ive been talking with my dad about turboing my car, granted i have a stock DOHC ka other than a dual exhaust cam swap, but needless to say its pretty weak. i would be running a turbo at or under 10psi. My father and i have been into model aircraft for quite sometime and jokingly he say "hell a ducted fan rc motor would give you that much for a hell of a lot cheaper." We both laughed at the idea and as we started to talk about it we realized that holy shit this might actuallly be a fun project to do. Now i have seen these rice ass kits using boat pumps floating around but i dont like the idea of having something that cheap feeding my engine. My dad is an electrical engineer so he has access to some shit that will help us do some [email protected] first. We could design a speed controller that is in proportion to the amount of air the engine gets at different RPM's so it would be acting like a turbo but obviously no where near the amount of power. These motors will push a 5-8 lb plane at over 90mph. I still need to look into the amount of CFM's a turbo charger will push and see how the calculations look and see if it would be worth the time and effort doing. I will eventually turbo the motor with a full rebuild but i figured this might be something fun to try.

this is something like i would use for the motor
Schubeler DS 51 DIA From Ductedfans.com USA (http://www.ductedfans.com/Schubeler_DS51_DIA.html)
44,000 rpms is the max for this one...

Since no one has tried this before to my understanding i thought i would share this off the wall concept and get your imputs. Again i laughed at the idea at first haha. Im not asking about those "electric superchargers" you see on ebay that use motors you can get at walmart.... so please dont hate :smash:

Walperstyle
01-31-2012, 10:42 PM
Very strange. I was thinking a similar principal regarding RC Jet engines though. Basically one separate motor to give you a constant, lets say 30lbs of boost, right from startup, not relying on exhaust or spool. (obviously, you can't blast exhaust gasses into an intake, so let me explain two methods)

You need to have a turbocharger, AND, a RC JET engine that can run on the same fuel as your car.

idea 1:
Intake = place the jet engine right behind the turbo so its sucking from the Exhaust housing. (basically where you would normally have downpipe)

idea 2:
Exhaust = Just have the exhaust gasses from the jet engine blast through the turbo like how a regular engine works.


BTW, people are probably going to come to this thread and confuse what you are saying with Twin Charging, or tell you about bi-turbo's, or twin scroll. we all know how that stuff works already.

Basically, You and I are both looking for a way to get 30PSI of boost, ALL THE TIME.




My RC Jet Engine spool explained

http://www.supercars.net/pitlane/pics/188621/2247351c.jpg
http://www.supercars.net/pitlane/pics/188621/2247351d.jpg

silver350z05rb
01-31-2012, 11:14 PM
mhhhhhhhhhhhhh interesting, cant wait

Walperstyle
02-01-2012, 12:04 AM
Basically, I wouldn't do do a separate boost creating method unless I could make lots of boost. Seeing as intakes can't take exhaust gasses, that was the best ways I though of attaching a separate motor to create constant boost.

Croustibat
02-01-2012, 01:39 AM
Okay fellow zilvians, ive been talking with my dad about turboing my car, granted i have a stock DOHC ka other than a dual exhaust cam swap, but needless to say its pretty weak. i would be running a turbo at or under 10psi. My father and i have been into model aircraft for quite sometime and jokingly he say "hell a ducted fan rc motor would give you that much for a hell of a lot cheaper." We both laughed at the idea and as we started to talk about it we realized that holy shit this might actuallly be a fun project to do. Now i have seen these rice ass kits using boat pumps floating around but i dont like the idea of having something that cheap feeding my engine. My dad is an electrical engineer so he has access to some shit that will help us do some [email protected] first. We could design a speed controller that is in proportion to the amount of air the engine gets at different RPM's so it would be acting like a turbo but obviously no where near the amount of power. These motors will push a 5-8 lb plane at over 90mph. I still need to look into the amount of CFM's a turbo charger will push and see how the calculations look and see if it would be worth the time and effort doing. I will eventually turbo the motor with a full rebuild but i figured this might be something fun to try.

this is something like i would use for the motor
Schubeler DS 51 DIA From Ductedfans.com USA (http://www.ductedfans.com/Schubeler_DS51_DIA.html)
44,000 rpms is the max for this one...

Since no one has tried this before to my understanding i thought i would share this off the wall concept and get your imputs. Again i laughed at the idea at first haha. Im not asking about those "electric superchargers" you see on ebay that use motors you can get at walmart.... so please dont hate :smash:

You should have started there. This would have made you abort immediately.

also remember : flow AND pressure ratio.

There is a reason why electric chargers dont work, and you can call or build them however you like (R/C plane engine with fan, big electric engine with turbo compressor wheel and housing and so on).

Basically your turbo flows 30-35 lbs/min with a pressure ratio of 1.7.

A fan has nearly no way to produce pressure, and even if it did it would not produce more then 1 or 2 lbs/min (yes, pressure again. It can propel 8lb plane, when there is a pressure ratio of a slight bit more than 1 needed ).

Now what would it do after that ? It will hinder flow. Most likely it will start by frying the electric engine, because the fan will be driven by the air. Then it will break and will kill your turbo. Maybe your engine too.

Now take a look at a turbo. It IS simple. You cant beat simple. It costs a lot because it needs precision to build, time to design and is not really mass produced. Not because it is hugely complex to build.

buentellomma
02-01-2012, 05:33 AM
Or just buy a turbo and be done

rcdad123
02-01-2012, 12:13 PM
back in the day there was a product called e charger. and it`s basically a ducted fan that was installed between the MAF and the throttle body. we had a dynojet at my work and this guy came in wanting to see if it would work. we dyno`ed his car with out it and with it. the way his set up worked was it would turn on for a few seconds when you step on the throttle. i don`t think it had a speed controller. it was just on or off. anyway, we found that it made a little bit more power on the lower rpm's but it made less on higher rpm,s due to having 2 pounds of boost till the engine required more flow and then it became a restriction on the intake. this was back in 98. i`m also into electric rc cars and the brushless motors these days are way better than the brushed motors we had back then. so i think it`s worth another shot.

jjps13
02-01-2012, 03:25 PM
Yeah that's basically the same reaction I had to my dad trying to convince me to try it just to see. I had some of the theories you guys have addressed in a much more simplistic manner. Idk I find it an interesting topic but the technical I get with it I start to realize why I was apprehensive from the beginning. It would be one of those types of thing to basically try it and see the outcome due to the relatively cheap cost.

jjps13
02-01-2012, 03:47 PM
back in the day there was a product called e charger. and it`s basically a ducted fan that was installed between the MAF and the throttle body. we had a dynojet at my work and this guy came in wanting to see if it would work. we dyno`ed his car with out it and with it. the way his set up worked was it would turn on for a few seconds when you step on the throttle. i don`t think it had a speed controller. it was just on or off. anyway, we found that it made a little bit more power on the lower rpm's but it made less on higher rpm,s due to having 2 pounds of boost till the engine required more flow and then it became a restriction on the intake. this was back in 98. i`m also into electric rc cars and the brushless motors these days are way better than the brushed motors we had back then. so i think it`s worth another shot.

Thats something we thought would happen so I believe with the amount of air going in to the engine naturally vs what the ducted fan would produce. Then see if it would help it or hurt it. And like you said that was in 98 and I know for a fact the ducted fans available now have come a very long ways. Thanks for the encouragement though I still want to look into it more before I turbo it lol

jjps13
02-01-2012, 04:18 PM
You should have started there. This would have made you abort immediately.

also remember : flow AND pressure ratio.

There is a reason why electric chargers dont work, and you can call or build them however you like (R/C plane engine with fan, big electric engine with turbo compressor wheel and housing and so on).

Basically your turbo flows 30-35 lbs/min with a pressure ratio of 1.7.

A fan has nearly no way to produce pressure, and even if it did it would not produce more then 1 or 2 lbs/min (yes, pressure again. It can propel 8lb plane, when there is a pressure ratio of a slight bit more than 1 needed ).

Now what would it do after that ? It will hinder flow. Most likely it will start by frying the electric engine, because the fan will be driven by the air. Then it will break and will kill your turbo. Maybe your engine too.

Now take a look at a turbo. It IS simple. You cant beat simple. It costs a lot because it needs precision to build, time to design and is not really mass produced. Not because it is hugely complex to build.

ahhhh i see... im not looking at what the ducted fan can do by itself in open air. i didnt take into account that the fan must provide an equal amount or more air to be suffencent. So basically it would be what it makes now NA, minus that amount from what the ducted fan would create in a closed air (intake). and basically to dumb it down its the question of if the fan would create more than enough and how much... but if you look right under the post that i quoted you one its basically the situation you were hypothetically describing... impressive!

Croustibat
02-02-2012, 06:48 AM
By reading my post again i realise it sounds offensive. Sorry for that, it was not intended.

But basically a fan will not work. What you are trying to do is called a charger, turbos or superchargers are refinements of the idea you came across. They have this design and not the design of a fan to achieve flow at desired pressure while optimizing flow (a fan does not blow air normally to its plane, it creates a 90° cone with a "black zone" in the middle).
Sizing a charger only depends on that: corrected airflow of the application ( wether it is a piston engine, a jet/heli turbine, an auxiliary power unit or anything) and desired pressure for that airflow.

If you still want to do it, dont forget you need to block the fan when it starts driving the electric engine, otherwise BOOM.

Walperstyle
02-02-2012, 07:19 AM
The fact nobody has trashed my ideas yet makes me want to try it, because a turbocharger relies on exhaust gasses to spool it up, where as a separate turbine engine could be used to spool the turbocharger. Imagine the posibility of 30lbs of boost at Idle...

...a whole new set of problems comes up, like having a controllable BOV/Wastegate to vent extra pressure sub 500 engine RPM. (otherwise, how the hell do you Idle)

Croustibat
02-02-2012, 08:21 AM
Your idea kind of "works". In fact, heli turbines and auxiliary power unit turbines work that way, there just is fuel injected and burned before the turbine wheel, you dont need a jet engine, just burning fuel :D

A more efficient and simpler idea is to place a heat resistant fuel injector in the exhaust manifold, and dump fuel when antilag is needed. The manifold temp is enough to self flame it. That method was vastly used before on ford turbo rally cars. I think subaru still use that. It works, but the turbo and manifold dont like it very much as they are not made to sustain fuel burning. Exhaust valves dont appreciate, too.

There is also a problem when getting permanently on boost: no vacuum. It means no brake booster.

rcdad123
02-02-2012, 11:33 AM
we had anti lag on a drag car before and it would leave the starting line with 40 psi of boost. this was back in 1999 to 2001. we had inconel turbine and headers to with stand the heat.

Walperstyle
02-03-2012, 02:21 AM
my idea has been done!!!
Development (http://raceenginedesign.biz/Manic-Beattie.htm)

vids
Nick Mann's Mannic Beattie hillclimb car - YouTube (http://www.youtube.com/watch?v=11687nVdzdk)
http://www.youtube.com/watch?v=gFNnXOAAhWI

This designer used a helicopter engine to spool the turbo instead of a RC Jet engine, but the same idea though. NO LAG!


http://raceenginedesign.biz/RED%20Images/carousel-trimmed.jpg
http://raceenginedesign.biz/RED%20Images/mannic-shelsley-aug05-comp.jpg
http://raceenginedesign.biz/RED%20Images/2005_0918Image0007.jpg
http://raceenginedesign.biz/RED%20Images/DSC00038.jpg
http://raceenginedesign.biz/RED%20Images/DSC00032.jpg



'Our results speak for themselves'

Phone John or Mike on Tel: 01952 727267 E-Mail [email protected]

We have a long experience of developing reliable competition engines for rally race sprint and hillclimb applications. Use vour experience for your next engine.

Latest Development
the Manic Beattie Hillclimb Car

The Latest unit of interest is the MANIC BEATTIE, an extremely innovative 4 wheel drive CLUBMANS type chassis designed by NIC MANN of the famous ROVER V8 TURBO MOGGY fame. We designed a special 1700 BDT unit with special cylinder head, bronze gas sealing rings and other trick bits, to produce at the moment around 400bhp.This unit is blown with an HELICOPTER TURBINE, which is mounted in the car and uses it’s own fuel system to produce boost which remains at a constant pressure at all times, is then fed into the BDT, permanent boost! NO LAG. This unit was mapped on our dyno using a RACE TECH DEVELOPMENTS ecu with a 6 layer mapping facility with fantastic results.

We had to knock a 12 inch diameter hole in the wall to get the exhaust out of the cell. As the exhausts on turbines are critical, restriction is bad news and so we ran the engine with no exhaust, it sounded like a 747 was flying over the workshop for two days!

NIC has just broken the 20 year old unlimited sports car record at SHELSLEY WALSH with a 26.43 second run.
THE sport of speed hillclimbing is one of man and machine against the clock. That never-ending desire to save the odd hundredth of a second can often become a life long obsession. To the driver, it is all about optimum starts,perfect lines and higher corner exit speeds. To the engineer, it means more power, better traction, improved chassis balance and long hours in the workshop in pursuit of the dream. Nic Mann’s quest for that one, perfect run dates back to the mid-1970s. Having just graduated from Aston University with an engineering degree and found work at Rolls Royce aero engines in Bristol, he took up sprinting. The car he used was his mother’s Morris Minor 1000, complete with 948 cc ‘A’ Series engine. Over a period of 15 years this was progressively modified. At one point it featured a turbocharged B series unit and, eventually, a turbocharged and intercooled Rover V8 with nitrous injection giving something in the region of 550 bhp.
To cope with the increased power the vehicle initially had a Ford live rear axle and, finally, a Jaguar XJ6 rear driveline.“Throughout this period it was fully road legal and was driven to and from meetings with the racing wheels and tyres strapped to the roof!” recalls Mann. In 1990, having reached a plateau in the car’s engineering development, together with the arrival of a new family, the car was sold to drag racer Bill Sherratt. It still competes in that category today.

So what does a seasoned hillclimber do when he has a budget of £10,000 just sitting there in his pocket? Obvious – he embarks on a new project!

“Since the Morris had over the years been something of a crowd pleaser, its replacement couldn’t be something ordinary,” says Mann. “Yet even in 1990 £10K wouldn’t get you very much of a competition car. “Analysis of the competition showed that successful cars were compact. With the opportunity for aerodynamic downforce limited because of the low average speeds, mechanical grip had to be maximised. Soft suspension (to cope with the uneven surfaces), large wings and the ability to maximise downforce from the underbody were also required. With two-wheel drive, the weight distribution would be heavily biased towards the rear, resulting in large weight variations on the front wheels during transient power changes and issues with handling and stability.” The successful cars had F1-derived power units but their power delivery was thought to be ‘peaky’, making car control even trickier in the confined width of a typical venue. The critical key features of any new design would therefore need to be: Maximise mechanical grip, which effectively meant four-wheel drive and low unsprung weight (with inboard brakes). Minimum weight and polar moment of inertia within the constraints of cost. Major components grouped around the centre of the vehicle and small diameter tyres. The latter also minimises the size and weight of the final drive transmission hardware. Minimise the effects of lateral weight transfer, while retaining a compact package. A low centre of gravity was considered essential while front/rear static weight distribution was targeted at 50:50. At 1G acceleration, the targeted centre of gravity should give a 1/3:2/3, front-rear weight distribution. Chassis construction technique had to be suitable for low cost home build consisting of a steel spaceframe chassis with separate bodywork. Eventually he concluded: “Careful consideration of all these factors pointed towards a layout with the engine in front of the driver and a ‘sports car’, Mallock type body with a four-wheel drive system based on a proprietary 4x4 transmission. Use of a flat floor allowed the hardware to be mounted as low as possible, with downforce generated primarily from the large wings allowed in the sport rather than from the underbody surface.” At this stage of the design process one could be forgiven for thinking that this was just a routine design and build exercise. However, it is in the power train where much of the real technical novelty resides. With the additional drag of the transfer gearbox and the forward drive system, not to mention the additional weight, Mann reckoned on needing at least 600 bhp on tap to generate the record-breaking performance he was looking for. Expensive F1-style ‘V’ engines were out of the question, not just on cost but because packaging in front of the driver would have been impossible.

Eventually help in the form of respected engine tuner John Beattie came to hand with the arrival of a 1700 cc Cosworth BDT. Canted over at only 25 degrees to the horizontal towards the intake side, this satisfied the requirement of minimum centre of gravity and minimised the frontal area and yet still left room for the driveline forward. “With 400 bhp the initial aim, it was evident that a move to a larger turbocharger and quite a large amount of boost would be necessary,” says Mann. “This would result in the dreaded turbocharger lag and while anti-lag or ‘bang-bang’ systems were considered, it was quickly decided to move to a much more radical solution.” Mann’s background in aerospace led him to a solution involving a helicopter gas turbine APU or auxiliary power unit. Supplied by Turbine Technologies Ltd of Carmarthenshire in South Wales, the unit is based on a helicopter emergency air start unit used to fire the main gas turbine engine on the ground.

Running separately from the main engine, initially on diesel fuel, the unit delivers air to the engine at a constant pressure independent of the main engine speed and hence totally eliminates the throttle lag normally associated with high boost turbocharged systems. Currently set at a very “modest” 25 psi gauge boost, the engine delivers something in the region of the initial target of 400 bhp at 7500 rpm. The torque curve is particularly impressive: from 2500-7500 rpm this doesn’t vary by more than 20% from the peak value. It is transmitted to the gearbox by a somewhat elderly AP Racing 7.25-inch triple plate, sintered clutch hidden within the radically modified Ford bellhousing. From the outset the car was designed around a Ford Sierra 4x4 MT75 gearbox, which at the second-hand going rate of about £300 each fitted nicely with the budget. However, as Mann was to find out later, this has been a major stumbling block to development.


With no finance to fund a dog gear conversion, he has resorted to removing the synchromesh cones to speed up changing gear. “Ratios are standard Sierra 4x4 with second gear giving 60 mph, third gear 90 mph and fourth 130 mph,”he says. “Fifth gear has been removed along with reverse, again to save weight. First gear is used only for tyre warming, starting for the timed runs being conducted in second gear.”With such a limited budget, it made sense to use not only the gearbox but as much of the other Ford Sierra 4x4 parts as possible, including the transfer box. Using the standard epicyclic transfer gear train and viscous coupling, drive to the front goes under the heavily-canted engine and up to the Lotus Elan-derived differential housing before cascading out either side, through the inboard ventilated disc brake arrangement and out to the modified Golf GTi Mk 2 front uprights. The brake discs, being inboard, are limited in diameter to 260 mm because of ground clearance considerations but with AP Racing 4 pot calipers, retardation isn’t an issue. At the rear, drive is much like the front with yet another 3.9:1 Elanbased diff, complete with limited slip differential, feeding the drive through a pair of Ralt RT32 rear uprights acquired during the protracted 10-year build. With all these shafts whirling around and the requirement to mount extra differentials and turbocharger units etc, Mann has erred very much on the side of safety and fabricated the spaceframe chassis out of predominately 11/8-inch by 18 swg (1.22 mm) CDS tubing. Although the car has never been weighed properly, all up weight is estimated at “a rather heavy 650 kg,” Mann wistfully reports, with the target 50:50 front-rear static weight distribution.

There is scope to significantly reduce weight by rationalising gas turbine and fuel system parts as well as those in the transmission but only when funds allow. Perhaps the biggest effort required in any home-build project is that of producing the bodywork. Always a compromise between effort required, weight and cost, the temptation is either to give up totally and hand it over to a professional or invest your own time in the tedious task of making a body buck, taking a female impression of this and then making the actual body out of carbon fibre/GRP. Wishing to eschew both options and using clear engineering logic, Mann’s answer was to make the front and upper bodywork out of sheet aluminium while the sidepods, incorporating the cooling system on one side and the turbocharger and oil tank on the other, were made out of 3 mm birch plywood. Carpenter Mann explains: “Although I was limited to 2D curves, the panels are bonded together using pinewood strips and coated with several layers of epoxy resin before being finished with a 2-pack polyurethane paint system. The resulting finish is exceptional with only a slight weight penalty over the more normal GRP arrangement.”

Starting the engine(s), as you might expect, is not that simple and is somewhat reminiscent of starting a helicopter. Since the turbocharger oil feed and scavenge system are operated off the main engine, this needs to be running first. Next in the strict sequence of events, the auxiliary gas turbine turbo unit needs to be started using compressed air from the off-board starter unit. At 1 psi boost with the turbo spinning at 10,000 rpm, ignition and fuel (initially diesel fuel held in a separate tank) can be switched on. At 5 psi the system is self-sustaining and the starter unit can be disconnected. At 13 psi with the turbine spinning at 40,000 rpm and the main engine at idle, the system is ready to go. Tyre burnouts are conducted at 13 psi boost in first gear but timed runs, for 2005 at least, used the higher 25 psi boost limit, manually selected from the dashboard Not surprisingly, there have been issues. “Control of the turbine was initially a problem,” he remembers, “with the unit flaming out upon changing gear and losing boost.”

The latest problems are more serious and potentially more expensive to fix. Out of the car’s first four meetings – one of which was the Shelsley Walsh Centenary event at which it lowered the hill record for Shelsley Specials by a magnificent half a second – two gearboxes failed. Each time the offending part was third gear on the MT75 gearbox when for the first time during a run the transmission experienced the full engine torque. Examination of those recognisable parts remaining suggested simple low cycle fatigue. In other words, the box is not strong enough! The winter rebuild was focused on improving the strength of the gearbox and reducing the inertia of the driveline. The weight of the propshafts (both front and rear) has been substantially reduced by replacing them with TORQline – carbon fibre wound – versions from the Crompton Technology Group. Support in the form of a 51/2” aluminium triple plate clutch has come from Tony Tewson at Superclutch, while a lightweight flywheel and starter motor were supplied by Ark Racing.

After tests conducted towards the end of last year, further weight has been saved by dispensing with the diesel fuel tank and running the turbine on gasoline fuel from the main tank. Along with the adoption of a lighter battery, the car now weighs 25 kg less. The major issue of the gearbox, however, has yet to be resolved. “The original plan was to graft the much stronger Borg Warner T5 gearbox complete with a Glebe Transmissions dog clutch conversion to the existing 4x4 transmission,” says Mann. “Unfortunately, since space is very tight, this wasn’t possible. “Plan B is to fit the T5 gears into the existing 4x4 Sierra casing. Rated at around 450 lbs ft (610 Nm), this should give me enough reserve to increase the boost pressure a little towards the 43 psi maximum – but maybe not this year!” While Mann has completed all the design work and manufactured the new gear linkage, he awaits the new gear parts with relish as the season gets ever closer. With a little extra finance from Aldon Automotive, the target is the Gurston Down event at the end of May. Fingers crossed.

Walperstyle
02-03-2012, 02:54 AM
http://www.youtube.com/watch?v=ee9H93uvYRo&t=25s

jjps13
02-05-2012, 12:57 AM
/\ thats awesome... i never even thought of your idea and thats so damn cool...!!!!