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Hi Erik
The length and diameter of the inlet (and exhaust) runners essentially define your torque curve (as a function of RPM) since they are a major contributing factor to engine volumetric efficiency. Adjusting the diameter of the runners defines the RPM at which peak torque is achieved, while adjusting the length tends to swing the curve about peak torque RPM. For example, long narrow runners will tend to deliver peak torque at low RPM, with a good deal of the full torque available below peak torque RPM, but will unfortunately fall off quite rapidly after peak torque RPM. Keeping the diameter the same, but making the runners shorter, will take away some of the low down torque, but will give back some of the torque lost above peak torque RPM. Long narrow runners are common on most modern petrol engines since they promote good volumetric efficency at comfortable RPM (usually around 3000 to 4000 RPM). Short, fat runners are common on racing engines that make very little low down torque, but make excellent torque at high RPM. This isn't a problem for racing engines, but wouldn't be good for your every day runabout. Also, power is the product of torque and RPM, so more torque at higher RPM means more power.
My manifold runners are longer and fatter than your average street car since it's my policy not to sacrifice low down torque on a turbo charged engine, especially on a rally car where low down torque can be quite useful. I determined my dimensions following a fairly detailed design procedure that included engine capacity, volume of air to be flowed, intended HP, etc. Then I threw darts at some pictures and picked one.
The length and diameter of the inlet (and exhaust) runners essentially define your torque curve (as a function of RPM) since they are a major contributing factor to engine volumetric efficiency. Adjusting the diameter of the runners defines the RPM at which peak torque is achieved, while adjusting the length tends to swing the curve about peak torque RPM. For example, long narrow runners will tend to deliver peak torque at low RPM, with a good deal of the full torque available below peak torque RPM, but will unfortunately fall off quite rapidly after peak torque RPM. Keeping the diameter the same, but making the runners shorter, will take away some of the low down torque, but will give back some of the torque lost above peak torque RPM. Long narrow runners are common on most modern petrol engines since they promote good volumetric efficency at comfortable RPM (usually around 3000 to 4000 RPM). Short, fat runners are common on racing engines that make very little low down torque, but make excellent torque at high RPM. This isn't a problem for racing engines, but wouldn't be good for your every day runabout. Also, power is the product of torque and RPM, so more torque at higher RPM means more power.
My manifold runners are longer and fatter than your average street car since it's my policy not to sacrifice low down torque on a turbo charged engine, especially on a rally car where low down torque can be quite useful. I determined my dimensions following a fairly detailed design procedure that included engine capacity, volume of air to be flowed, intended HP, etc. Then I threw darts at some pictures and picked one.
Managed to grab a few days before Easter to begin the manufacture and installation of the roll-cage. It's an integral part of the chassis so it's more of a space-frame construction than an addition to the chassis, but difficult to tell the difference. I have also set up my steering and pedals. I'm using the fairly long steering column from an E36 BMW as this mates with the E30 steering rack without complication and places the steering wheel quite far back. The current steering wheel is useful for maneuvering the car around the garage, but will eventually be replaced by a Sparco wheel. The clutch and brake pedals are by Tilton. There is no brake booster, as is typical of this sort of car. There are however separate brake master cylinders for the front and rear brakes. The two master cylinders connect to a Bosch-5 ABS/TCS unit before connecting to the front and rear wheels. The brake fluid reservoirs are mounted separate from the master cylinders, which is necessary since the cylinders are mounted at an angle. I have selected two 19mm diameter master cylinders for the front and rear brakes, and a 22mm diameter cylinder for the clutch. The front-to-rear brake bias can be adjusted at the brake pedal, which I will adjust slightly in favour of my front brakes due to the car's mass distribution.
No need to say anything about the following pictures, I think they say what this project is all about.
Next job is to finish welding up the roll-cage (I still have to install the diagonals). Then the whole thing gets sandblasted and painted. I've opted to paint rather than powder-coat. That way I can touch up the paint after any additional welding. After that I'll install the radiator and intercooler; plumb and wire the engine, clutch and brakes; and then fire up the engine. Once the engine is running I'll probably put the rolling chassis on a hub-dyno before continuing with the bodywork.
Further news is that Polytechnic have finally finished manufacturing my fibreglass panels and bumpers. I wonder how long it will take before the panels arrive in SA :roll: .
Next job is to finish welding up the roll-cage (I still have to install the diagonals). Then the whole thing gets sandblasted and painted. I've opted to paint rather than powder-coat. That way I can touch up the paint after any additional welding. After that I'll install the radiator and intercooler; plumb and wire the engine, clutch and brakes; and then fire up the engine. Once the engine is running I'll probably put the rolling chassis on a hub-dyno before continuing with the bodywork.
Further news is that Polytechnic have finally finished manufacturing my fibreglass panels and bumpers. I wonder how long it will take before the panels arrive in SA :roll: .
This is my intercooler in position on the front of my R5. It's a large intercooler which should provide the cooling I need to run at a continuous power of around 250HP, and will happily accomodate 350HP for several minutes before the body of the cooler becomes hot enough to influence the performance of the engine. Notice how the outlet from the intercooler runs straight into the inlet manifold. Unfortunately, due to space constraints, my radiator sits about 8cm behind the intercooler, which will reduce the air flow through the intercooler somewhat.
Blimey, that is a big one! Will the radiator still be able to keep coolant temperatures under control in your hot climate with that in the way? I always assumed that you'd want to keep one item away from the airflow of the other. Intercooled performance cars that I have owned have their intercooler/radiator arrangement either side-by-side at the front (Lancia Integrale), or completely remote (Turbo 2), or with the intercooler above/behind the engine (Subaru Impreza) with air fed through the bonnet vent.
Thanks for the comment Michael,
Intercoolers and radiators in series are not a problem so long as the intercooler comes first. Due to the very low heat capacity of the air passing through the intercooler, the large volume of air coming off the back of the intercooler will be around 10 to 15'C hotter (with an intercooler this big, worse with a smaller intercooler) than ambient at full power (at speed, with air flow, obviously). Fortunately the objective is not to cool the radiator to ambient temperature (like the intercooler, if possible) but rather to cool to around 75' to 90'C. Thus I will be using the largest radiator I can fit to provide sufficient cooling using air that has been "pre heated" to around 35' to 45'C. Also, the radiator extends much lower than the intercooler and will include a scoop to funnel cooler air up into the radiator to supplement the reduced air flow due to the intercooler. The biggest problem with keeping the radiator cool is not the temperature of the air coming off the back of the intercooler, its the reduced air flow due to the surface area of the intercooler! This is why my scoop underneath the front of the car and the 8cm gap between the intercooler and radiator is so very necessary.
If I could have I would have done it differently, unfortunately I am restricted by space.
Regards
Geoff
Intercoolers and radiators in series are not a problem so long as the intercooler comes first. Due to the very low heat capacity of the air passing through the intercooler, the large volume of air coming off the back of the intercooler will be around 10 to 15'C hotter (with an intercooler this big, worse with a smaller intercooler) than ambient at full power (at speed, with air flow, obviously). Fortunately the objective is not to cool the radiator to ambient temperature (like the intercooler, if possible) but rather to cool to around 75' to 90'C. Thus I will be using the largest radiator I can fit to provide sufficient cooling using air that has been "pre heated" to around 35' to 45'C. Also, the radiator extends much lower than the intercooler and will include a scoop to funnel cooler air up into the radiator to supplement the reduced air flow due to the intercooler. The biggest problem with keeping the radiator cool is not the temperature of the air coming off the back of the intercooler, its the reduced air flow due to the surface area of the intercooler! This is why my scoop underneath the front of the car and the 8cm gap between the intercooler and radiator is so very necessary.
If I could have I would have done it differently, unfortunately I am restricted by space.
Regards
Geoff
Almost ready to fire it up and test. I wish my body panels and new bumpers would hurry up and arrive. Will Falkener at Fast Car Spares http://www.fastcarspares.com has ceased to answer my emails. I'll reserve judgement for the time being, but needless to say I'm not happy. I just wish he would bring me up to speed on why Polytecnic have taken so long to manufacture my parts. If he could supply me with a reasonable explanation it would begin to look less like like he is running a scam. However, it's difficult to pass judgement on a situation where Idon't have all the details, instead I become highly frustrated while being left in the dark :cry: .
I have just received word from Polytecnic that my panels and bumpers were finished at the end of January already !! I've been in touch with Fast Car Spares and needless to say I am not impressed! It appears that complications have arisen between Fast Car Spares and Polytecnic. I shan't go into the details out of respect for Will Falkener, who has now committed to sorting the problem out and expediting the delivery. So for the time being my car remains in the nude :cry: 
:evil:
:evil:After collecting the frame from the sandblaster I spent the weekend applying primer. The Frame has turned out fantastic and I am extremely pleased with the finished product. I estimate at least another six to eight months on this project, but it's the home stretch from here on! Next step is to have the remains of the body (A, B and C pillars, plus roof) chemically dipped and stripped. I have also purchased 10 litres of "Renault-Yellow" 2K paint. I plan on finishing the car off similar to the famous no. 77 R5Turbo track car (Anyone know anything about the history of that car?).
You mean the IMSA GTU Renault LeCar Turbo. Pascal's book provides following info: "For the 1981 season, Patrick Jacquemart, head of competition service department in the USA had a very special R5 Turbo prepared in his workshop to contest the IMSA series. This very exotic machine entertained the US public with its power and road-holding. Its engine had been prepared by American specialists Katech Inc., who increased the cubic capacity to 1430cc with a compression ratio of 6.5:1. Mechanical fuel injection was installed. This very special car, whose chassis number was RR03T, developed 260BHP at 7000 RPM. The attractive bodywork with new wings, rear spoiler and magnificent 16" wheels was formed by Renault Racing of Belleville, Michigan. Patrick Jacquemart was killed at the wheel of this car whilst testing on the Mid Ohio circuit close to Lexington."
Paraphrasing Meaney's 1996 book, there were two Jacquemart space frame cars. One as above was destroyed, killing the driver: it was subsequently rebuilt and turned up in the U-Haul museum in Arizona. The second which was known as the Roller and was used for testing was being rebuilt at that time in New York.
I would recommend that you post your question on the Yahoo! R5 Turbo forum: the American contributors may well be able to help you out further. I think I remember one of them mentioning a similar-looking part-finished car at a workshop over there, whether there's any connection or not I don't know, but one of them is sure to know about the racing career etc. and probably the lcurrent location of any surviving car(s).
Paraphrasing Meaney's 1996 book, there were two Jacquemart space frame cars. One as above was destroyed, killing the driver: it was subsequently rebuilt and turned up in the U-Haul museum in Arizona. The second which was known as the Roller and was used for testing was being rebuilt at that time in New York.
I would recommend that you post your question on the Yahoo! R5 Turbo forum: the American contributors may well be able to help you out further. I think I remember one of them mentioning a similar-looking part-finished car at a workshop over there, whether there's any connection or not I don't know, but one of them is sure to know about the racing career etc. and probably the lcurrent location of any surviving car(s).
Thanks for that Michael. I wasn't aware that someone had died in that car! I hope that I have better luck with mine. I originally intended my project to be a rally car. However, with the limited number of rally classes in which I can compete over here, most of which prohibit cars with a modified chassis (as is the case with mine) I eventually opted to build a track car. Since my front and rear track-width (coutesy of the BMW E30 suspension components) are similar to the IMSA GTU R5 Le Car, it just made sense to make mine a replica. I am sure that it will be a very special little car when it is done.
After painting the frame I have begun reassembling the car. During this process I've been asking myself, is this a Renault 5 or isn't it? While it's true that a R5 body fits over the frame, and the engine does have a turbo, the car is neither an R5 turbo, nor an R5 Alpine (Gordini in the UK). This car may be front engined (like the Alpine), but is quite uniquely rear wheel drive. Certainly nothing special when compared to other cars, but unique in terms of the R5 I believe. I guess this car will technically be an R5 since it is the shape and form of a vehicle by which it is identified, but much like the old Group-B rally cars, the term "highly modified" will apply. In this case accepted to mean an R5 body stuck over custom everything else. I mean, really, its a bit like I discarded everything from the windscreen wipers down. And the Toyota engine, well don't get me started on that - it's mostly about horsepower - but more to the point, I can't imagine a Renault engine doing it for this car, although I'd be quite happy to put in a Megane turbo engine if I could afford one.
The remains of the body are currently being sandblasted. I couldn't find anywhere locally that could dip-and-strip it for me, so sandblasting will have to suffice. That likely means I'll have to apply plenty of filler-primer to secure a decent texture free surface for the colour.
The remains of the body are currently being sandblasted. I couldn't find anywhere locally that could dip-and-strip it for me, so sandblasting will have to suffice. That likely means I'll have to apply plenty of filler-primer to secure a decent texture free surface for the colour.
You know its a small car when you can fit the body on the work bench. Sandblasting the body revealed a few dents in the roof hidden by bodyfiller. I'll beat these out rather than fill them again. Then the body will be primed with a two part etch primer and the interior painted yellow to match the frame. I'll paint the exterior yellow once I've fitted the rear fenders.
Busy working on the body so no further pictures at this time. Took me 3 weekends to straighten out the roof. Previous owner was too lazy to remove the headliner in order to repair what appears to be hail damage, and so just filled the dents with bondo. After sandblasting you could have played a round of golf on this things roof! Anyway, it's all properly straightened out now with only a liberal smear of bondo to hide a few stretch marks. All it takes is a decent set of hammers and dollys, and a lot of time and patience.
Further news is that my Koni coil-overs will soon be ready for the front suspension. It's still basically an E30 design, but has been modified to accept coil-overs. I will now be able to adjust my front suspension to the correct height, and select springs with the correct spring-stiffness for my application. I will deal with the rear suspension in due course.
Rumour has it my body panels and bumpers are about to arrive, but I shan't hold my breath.
I'll post further pictures when I get some paint on the interior of the body.
Further news is that my Koni coil-overs will soon be ready for the front suspension. It's still basically an E30 design, but has been modified to accept coil-overs. I will now be able to adjust my front suspension to the correct height, and select springs with the correct spring-stiffness for my application. I will deal with the rear suspension in due course.
Rumour has it my body panels and bumpers are about to arrive, but I shan't hold my breath.
I'll post further pictures when I get some paint on the interior of the body.
... I dont want to turn this into a slanging match with K-Jet vs EFI, but there are 3 5T's in Oz that are running full EFI systems, none have had any serious issues in tuning or setup & they all run extrememly well.
The fact that we make so many good ECUs down here probably makes a slight difference too
The fact that we make so many good ECUs down here probably makes a slight difference too
Nate, You're right about Oz making the best ECU's. Any idea what happened to Autronic? They were popular here in SA, but seem to have dropped off the planet. I'll be using the Adaptronic on my R5turbo look-alike car, also an Oz product.
I suspect the US would make some pretty good aftermarket ECU's if it weren't for the fact that they are prohibited in many states due to emissions laws (they have to keep the OEM unit intact). I think you can eventually fit them, but have to jump the car through hoops to get the system certified environmentally friendly (Sorry US readers if I've got this wrong).
In defence of Andy's decision and Jan's comments, I can see the logic in making an existing system work rather than going through the problems of setting up a whole new EFI system. There's no defending the fact that the old K-Jetronic can be repaired and made to work again far quicker than setting up a new one, especially if you have to replace the throttle body, and maybe even build a new plenum in order to implement an EFI system. I also support any decision to maintain the value of a stock item. With that said, I still prefer modern EFI systems and can't wait to get my Adaptronic operating
In my personal experience I've seen very few problematic aftermarket ECU controlled EFI systems (with the exception of the cheap and nasty ones where you deserve what you get), only problematic owners. Most go back to the dyno in search of more power and are forever chopping and changing bits on the engine in order to get that extra bit of acceleration. Some even refuse to set a wheel on a dyno and spend years mapping the thing the hard way. However, I'm not sure that I've heard of anyone going back to the dyno in order to improve the reliability of the EFI system or to answer similar problems to those experienced with the K-Jetronic? It just doesn't happen.
But lets face it, car ownership is about getting the most of what WE want out of them. It's up to us what we do with our own cars and for me, building my own car is the project of a lifetime. For others its about other things and I deeply respect that.
I suspect the US would make some pretty good aftermarket ECU's if it weren't for the fact that they are prohibited in many states due to emissions laws (they have to keep the OEM unit intact). I think you can eventually fit them, but have to jump the car through hoops to get the system certified environmentally friendly (Sorry US readers if I've got this wrong).
In defence of Andy's decision and Jan's comments, I can see the logic in making an existing system work rather than going through the problems of setting up a whole new EFI system. There's no defending the fact that the old K-Jetronic can be repaired and made to work again far quicker than setting up a new one, especially if you have to replace the throttle body, and maybe even build a new plenum in order to implement an EFI system. I also support any decision to maintain the value of a stock item. With that said, I still prefer modern EFI systems and can't wait to get my Adaptronic operating
In my personal experience I've seen very few problematic aftermarket ECU controlled EFI systems (with the exception of the cheap and nasty ones where you deserve what you get), only problematic owners. Most go back to the dyno in search of more power and are forever chopping and changing bits on the engine in order to get that extra bit of acceleration. Some even refuse to set a wheel on a dyno and spend years mapping the thing the hard way. However, I'm not sure that I've heard of anyone going back to the dyno in order to improve the reliability of the EFI system or to answer similar problems to those experienced with the K-Jetronic? It just doesn't happen.
But lets face it, car ownership is about getting the most of what WE want out of them. It's up to us what we do with our own cars and for me, building my own car is the project of a lifetime. For others its about other things and I deeply respect that.
GeoffBob said:
Motec, Autronic, Wolf3d, Haltech... all Aussie
Autronic is still solid: http://www.autronic.com.au/
(he's one of the guys that started Motec! so a VERY similar ECU at a fraction of the price) The guy that runs/owns it has a "very" prompt V6 Pug so he loves Frenchies.
The Haltech's also get a VERY good rep & the T1 in WA http://www.r5turbo1.net/gallery.php uses the Haltech (blew the motor at 380hp, rod through block)
I had a lot of discussion with both Autronic & Haltech, both companies have great support & its a phone call away.
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