supercharged 1275 home brew. anybody fancy a blown minor?

Post by **superchargedfool** » Thu May 28, 2009 2:52 pm

OH
YES

OH

YES YES YES

My chuff is well and truly chuffed.

I have just driven my moggy for the first time with the new engine, panhard rod and Air to fuel meter.

Its awesome. Excuse me big upping my car but I am toooo happy.

The new engine:

Sounds so sweet and drives so lovely on part throttle. Can't wait to get it set up and run in and be able to give it large.

The panhard rod made from bits and bobs, no attempt at beauty just strength:

The rear feels totally different, it goes more where you planned than where it feels like.

The drivers view showing the Weber Alpha afr:

What I find so funny is that it shows the engine is running quite close to perfection on part throttle without having been any where near a tuner yet.

My love and kid like feelings for this car/project are back with serious zest.

Post by **superchargedfool** » Mon Jun 01, 2009 4:59 pm

car went to tuners on friday. I have just spoken to them and they are starting to play with it. One of the first runs on the dyno with everything safe but miles from being right had mid 80's bhp at the wheels so about 110bhp flywheel.

Tuner man was laughing as he told me because I had asked is it looking ok or have I got problems or do I need to do something diff or......... And he cut me off and told me about that early run up and said I have nothing to worry about and all will be seriously good.

I cannot wait. I am struggling with my kidlike xmas eve kind of feelings.

Post by **Mogwai** » Tue Jun 02, 2009 6:33 pm

superchargedfool wrote:
I cannot wait. I am struggling with my kidlike xmas eve kind of feelings.

Im the same, Ive got a roling road session booked soon

Post by **superchargedfool** » Fri Jun 05, 2009 9:08 am

well I have to fetch the car from the tuners today to fit a smaller charger drive pulley.

It turns out my boost gauge doesn't tell the whole truth.

I thought I had 10 psi, turns out to be more like 12.5psi. It appears the charger is being slightly over driven and creating a lot of charge heat, which is causing detonation unless timing well retarded.

No big problem, sort pulley and take back.

Post by **bmcecosse** » Fri Jun 05, 2009 9:30 am

Well done! Earlier you said you were fitting an 'intercooler' - and I was wondering how you would do that!!!!!!!! Compressing air always generates heat - lots of it! It's the major problem - causing pre-ignition/detonation = wrecked engine. You may want to consider a little water injection at full throttle.
Interested to see more detailed views of the Panhard rod - the location on the nearside chassis rail ?

Post by dp » Fri Jun 05, 2009 4:41 pm

Excellent read. If I may ask, where do you get the different pulleys from to change the supercharger drive ratio?

Post by **superchargedfool** » Fri Jun 05, 2009 5:05 pm

dp wrote:Excellent read. If I may ask, where do you get the different pulleys from to change the supercharger drive ratio?

You look under lots of bonnets with a vernier till you find something suitable, then go get one and lathe it up so its true and make an ally adaptor boss. Lots of messing about I'm afraid.

I have spent a couple of hours today trying to find a 5 or 6 rib 98 to 100 pulley and am still looking.

Post by **bmcecosse** » Fri Jun 05, 2009 6:04 pm

" well I have to fetch the car from the tuners today to fit a smaller charger drive pulley "

To make the scharger run more slowly - you need a larger pullley - NOT smaller.

Post by **superchargedfool** » Fri Jun 05, 2009 7:22 pm

bmcecosse wrote:" well I have to fetch the car from the tuners today to fit a smaller charger drive pulley "

To make the scharger run more slowly - you need a larger pullley - NOT smaller.

NO. to make the charger run slower means a smaller pulley! I am changing the one on the front crank pulley.

You presumed changing the chargers pulley. The charger pulleys are expensive and unique. My crank pulley is a damped type machined with an ally boss caphead bolted on to take a.n.other pulley.

I have now found that an early laguna 8v power steering pump pulley is perfect, guess where I will be tomorrow morning getting a pulley?

the scrapyard.

Post by **bmcecosse** » Fri Jun 05, 2009 7:34 pm

Ahhhh - my apologies! As long as you retain the all-important damper! I hope the drive pulley is attached to the central solid part of the damper - and not to the rubber mounted outer rim.

Post by **superchargedfool** » Sat Jun 06, 2009 9:42 am

bmcecosse wrote:Ahhhh - my apologies! As long as you retain the all-important damper! I hope the drive pulley is attached to the central solid part of the damper - and not to the rubber mounted outer rim.

yes. the damper pulley has had the inner face trued up in a lathe. It is bolted on as normal but with no lock washer. The ally adaptor is a snug fit in it and is bolted on by 3 cap heads that are recessed. It works a treat and means that to try a different drive ratio we find the right size pulley on something else and make another ally adaptor to suit. We may end up with quite a selection in the end.

Post by **superchargedfool** » Sat Jun 27, 2009 9:18 am

Well. I now have a 100mm drive pulley giving me a 1.5:1 drive ratio and 9.5 psi.

Set timing to 4 degree and it goes like stink. BUT.

I know from my experience with this car that it still isn't making much over 100 to 110 bhp. It will go on rollers next thursday to find out.

It also pinks a little when fully warm after a good long thrashing because the extra hot piston crowns plus hotter supercharger causes too much charge heat.

My realisation is that without cooling the charge I cannot make big power like all the mini boys claim.

I suspect that most of the power claims I have seen for supercharged mini's without charge cooling of some kind are cobblers. Very optimistic rolling roads or just lies.

There I have said it.

Still, no problem. If thursday shows I am right then it will come to bits and go blow through quickly.

I fancy the idea of a big intercooler and a blow through carb with the added bonus of the charger can go on the cold side of the engine as well. Who said this was going to be easy eh?

Watch this space 140bhp plus honestly is coming from this little a series even if it kills me!

Post by **bmcecosse** » Sat Jun 27, 2009 9:30 am

The Mini boys use water injection at high revs - that's what makes the cooling! Try it - I'm sure I've read of screen washer pump being used for this. Also - if you allow it to 'pink' at all you will have holes in pistons - so either reduce the boost or retard the ignition at higher revs by reducing the centrifugal advance. Remind me - what cam is in the engine ?

Post by **superchargedfool** » Sat Jun 27, 2009 9:54 am

cam is a 266. its about right for what I am doing.

I am not allowing it to pink, I just know its there if I let it but only after a good thrashing.

Don't get me wrong it goes like the clappers. First gear is all wheelspin unless you control it and second can get squeally.

I have thought about water injection. But there are many charged minis without it claiming big figures that I now don't believe one bit.

I feel a big intercooler and blow through would be more old school and in keeping with the car.

Post by **bmcecosse** » Sat Jun 27, 2009 11:46 am

It's your choice ! You could just use an octane booster - but I believe water IS the way to go - and simple enough to do. Intercooler is more essential on turbo cars - because the heat transfers through from the turbo as well as the compression heat - so the inlet charge is hotter than with a super charger. Would be interesting to know the actual temperature of the inlet charge just before it enters the head? This would tell you if a cooler would help significantly - or not. As you know - superchargers are more about torque all through the rev range - rather than top end power.
It does sound great - I'm very jealous!!

Post by **MartinB** » Sat Jun 27, 2009 12:32 pm

You're right, there is a hell of a lot of cobblers talked about power figures out there. Rolling roads can virtually be made to read what you want depending upon calibration, air temps, tyre pressures, gear ratios etc. Should only really be used as a comparator against what you already have so you can make sure the car is tested with as near identical set up to establish what the differences are with the engine performance. All figures should be corrected for standard air temp and pressures.They are also ok for setting AFR & ignition timing but fine tuning can be done with a datalogger in use.

Wouldn't bother with water injection, its like using a fire extiguisher in my opinion. Much better to use air to air intercooler or air to water charge cooler.

Sounds good fun though.

Martin

Post by **superchargedfool** » Sat Jun 27, 2009 12:48 pm

I am very certain my problem is heat because if you warm engine up a little from cold and then give it one quick power run it will make the power without pinking but after that it gets tricky. Only difference I can see is heat.

I think blow through is coming here soon.

I have been looking under the bonnet and I don't think it will be too easy to mount on the o/s. So I think N/s for charger is still the way to go.

If I make an inlet manifold for the carb that is long, I can fit the charger in the gap between carb and rocker cover if I put it on its side.

Post by **bmcecosse** » Sat Jun 27, 2009 2:35 pm

For a trail with water - all you need is a washer bottle with pump - and a length of tubing with nozzle set at the carb intake. When running full throttle - trigger the pump - simples! All the WRC cars use water inejction - it's very standard practice - and it certainly doesn't 'put the fire out' - in fact extra moisture enhances the burning rate at these temperatures - and keeps everything nice and clean too! Blow through carbs are lots of trouble - but a measure of that inlet temperature as the engine is just now would tell you if an intercooler was going to do anything worth while.

Post by **MartinB** » Sat Jun 27, 2009 3:05 pm

I believe the washer pump set ups usually spray water onto the intercooler to enhance the efficiency of the intercooler. I think some of the WRC road car clones are fitted with them (Subarus etc). I tried that myself a few years ago. The proper water injection kits I think run at much higher pressure and give a very fine mist, not something the washer pump will ever do. I personally would never use a washer pump to squirt water into a carb intake!

Post by **superchargedfool** » Sat Jun 27, 2009 7:43 pm

no.

the pump needs to be of a higher psi than the boost which rules out the washer pump type.

And the nozzle needs to be an atomiser type with about 0.5mm nozzle.

Also the nozzle must be safe as in assembled in such a way that if it comes to bits the end or internals dont go in.

I have thought about water injection with an erl system, I have an mf2 driver kicking about as well. But I think if temps are my prob then blow through with a large intercooler is easier and more old school.

I also happen to have a montego turbo intercooler which is quite large.