Hello people, As the title suggests I am trying to add a supercharger to my 1.8 litre 8v engine. The supercharger I am going to use is an Eaton M45. But I am encountering a few issues that I want to solve before actually beginning the build. I am trying to figure out what the best setup would be, Ideally I would want the throttlebody before the SC but this is not going to work since I cannot move the monopoint unit. So I want to build it like this: Air filter -> Supercharger -> diverter valve -> monopoint -> throttlebody Will this work? And how would I go about increasing the fuel injection in the monopoint unit? Also how would I calculate the pulley size for the SC? I am going for a budget boost build to get to around 150HP Some specs: 1.8 8V ABS engine with 160.000 KM Car red line = 6,500 RPM SC red line = 14.000 RPM Eaton M65/M45 Eaton M45 airflow = 45in3/rev = 737cc/rev
Are you going to run aftermarket injection such as megasquirt? Or stick with the monopoint unit? Would the single injector give enough fuel? Think there may be a renault alternative single injection set up that fuels more, or is there a possibility of fitting a 8v gti inlet to the 8v cabrio engine? Unsure of swappability. I've supercharged a few classic cars, but always used a carburettor on them before the charger, Have a look at vmaxscart and the mini stuff, or the car kitchen. Not sure what supercharger is used on the mx5 kits, but might be worth looking at inspiration there too. The Eaton is a good charger, but is a little heavy and bulky to mount in some situations, and loads of info about. Pulley ratios, etc. I had custom bottom pulleys made, one ran 2 belts for alternator + water pump, and separate belt for blower. Other used one belt for everything but I modified the alternator and water pump to run matching the ribbed belt. Programmable ignition at least is a good idea to map out the problems with that side, ran a dizzy on my minor, and it was OK, megajolt on the mini and was a far better beast. Lowered compression with a solid 'head gasket' a plate that is identical to and with a gasket on each side. Trust me it's not as easy as getting a £150 Cooper s used one and bolt it on, not putting you off, but you could get 150bhp much easier, cheaper and off the shelf, you're probably going to need bespoke manifolds, pulleys, injection system, mounts etc. And that's if the bottom end and gearbox is strong enough. Go for it, but research is crucial on this one I'm afraid, you may decide a 1.8t swap, or even a pd130 to be another option.
Have you actually investigated the packaging of the supercharger to the engine in a mock up? Drive belt tension has to be considered as well as drive belt durabilty. Do you understand the effects to cylinder fill on a 1781 cc low compresson engine and how this affects torque, before just targetting "150bhp"? 150 bhp @ what engine speed and how would such a target and single point correlate to drivablity? Becuase it does not. At full load, you need to model in your mind what the torque curve will look like and how you use hardware to influence. If you want to control transient driveablity, you must consider how you would vent excess charge air at idle. In order to reduce charger intake noise, you have to consider the throttle body location . The only best way to taken on this task, is by understanding engine fundamentals and the EA827 and if the hassle you will experience of creating such a powertrain is really worth it, over a tried and tested 1.8T. I did tuned the most Eaton M45 and M62 16v engines here in the UK and if I had to do that again, I would just recommend using a 1.8T. Sorry to break it to you, but the physics, knowledge and costs limits, what you will achieve and what you percieve in this case.
I already have made prototype mounts for the SC and I know it will fit with the tensioner I have in mind. I'm not too worried about the noise. I don't want to turbo the car because I thought a supercharger build would be simpler and cheaper. I just want more power for a short while until I finish my VR6 engine that I want to swap in later down the line. I did some research and thought it wouldn't be too much of a challange in a low boost type of application. 1.8t swapping would be better but that would kind of defeat the purpose of going this route. I just want some more power so I can keep up with my friends. Getting upgraded cams and lightweight hardware is kind of expensive where I live so that is why I started looking into superchargers.
I would likt to keep the monopoint but I don't know that is possible. Megasquirt would be a good option. I know a 16v head with multipoint injection would fit but that would require a lot of new parts and changing stuff and I kind of want to avoid that. Maybe it is impossible what I'm trying to do but then again I have seen working cheap SC builds. Just none using monopoint injection. The power gained is not much but more than I would get by just tuning the stock engine with bolt on parts like cams etc.
Cool. You are underestimating the work involved to get that set up to work properly, especially on an 8V engine and the maximum speeds it turns at. This is not my first rodeo with this sort of stuff and a proper build is not cheap. However your car and good luck with it.
Just tell your mate to slow down and you speed up with your VR6 engine. Put the money in to the VR6 swap, the 1.8v engines in MK3 are great and bulletproof if you service them and leave them alone, may be a performance cam if you’re feeling fruity. Personally, all the money I was going to use in a short term supercharging job, I’ll be getting the chassis sorted for when you place the heavier VR6 engine in, sort the handling, sort the stopping and you’re friends might not be as ‘fast’.
