Yeah I.seen that ... Loving the look of the engine , but can't quite work out from it what exactly I need ?

This was my diy mp45 conversion to my mx-5 - it has a twin throttle set up to maintain boosted air of throttle to give the instant torque and power that and FI car cant normally do and will even better some IRTB'd cars.

I'm wondering why nobody has done a twin throttle on a G? I'm sure it would be obvious if I knew more about them.

They have a boost return valve instead, which opens as the throttle closes. Charge air is then recirculated through all the boost pipes and 'charger.

I take it that the dual tb setup is a way of stopping boost from being built up behind a closed tb? Blocking the air being sucked into the charger on closed throttle with the second tb so the charger can't blow boost at the closed butterfly original tb on the intake? (thats how it would work in my head anyway).

You need cams in a 1.6 AFH hybrid to get that power with the naturally aspirated lump, which don't come cheap.

They may not be cheap but a 1.6 hybrid with cams would probably still be cheaper than a G40 conversion + chip and pulley and every thing else needed to get it to a reliable 150bhp

I dunno, G40s are cheaper than they've ever been, and I got a crashed donor car for £900 9 or 10 years ago when the values were much stronger. By the time you've got an AFH conversion with ECU etc, AVY bottom end and a pair of cams from Schrick at £500ish I don't reckon there's much in it. Difference is that if the AFH setup goes tits up your chances of finding spares easily and cheaply is far higher than with the G40, and you've not got 'charger rebuilds to worry about.

You still planning on boosting an AFH? I mapped an AEA last week running 0.7 bar of boost, and that's not bent any rods yet. Will be interesting to see how far they can be pushed. TSR stopped selling the turbo kits for them back in the day because of banana rod issues, but you never know whether that's because people had been throwing bleed valves onto them and winding the boost right up.

Hahaha I'm gonna boost mine fuck it, then dump it in something the weight of a shoebox

This was my diy mp45 conversion to my mx-5 - it has a twin throttle set up to maintain boosted air of throttle to give the instant torque and power that and FI car cant normally do and will even better some IRTB'd cars.

I'm wondering why nobody has done a twin throttle on a G? I'm sure it would be obvious if I knew more about them.

They have a boost return valve instead, which opens as the throttle closes. Charge air is then recirculated through all the boost pipes and 'charger.

I take it that the dual tb setup is a way of stopping boost from being built up behind a closed tb? Blocking the air being sucked into the charger on closed throttle with the second tb so the charger can't blow boost at the closed butterfly original tb on the intake? (thats how it would work in my head anyway).

Sort of but not quite.

The mp45 already has a bypass valve like i think the G has for when not on boost.

The guy who first did twin throttles to a hot side charger over here as far as we know or on this application at least had spent the last few years installing coldside chargers from kits supplied by an american firm. The throttle response of the boosted air travelling only 4 or 5 inches form a coldside charger and not having to build boost through 3 feet or more of pipe work and all the restrictions the bends and maybe an intercooler was astonishing. We actually found that people with coldside set ups were getting massively low intake temperatures in comparison as the restrictions and forces through the pipe work made intercoolers not required and the charger could be spun up to 30% slower for the same boost. So you can see there was a lot more power to be had without as much upgraded and stressed components.

Also the charger kits on sale for the 5 which were £2500 for a basic one and even the better ones seemed to all suffer a little idle droop which people countered with higher idle and all sorts of custom valves or whatever.

Running a stock throttle pre charger which is always slightly further open then the main one meant as soon as you went back on the throttle you had a whole system of boosted air immediately flowing in.

It is a great system and I'm not sure from the description above the G does. The valve mention seems to be the same as the bypass valve in function not the throttle response issue solution. However, I'm not an expert so happy to be right or wrong or halfway between...

Edited 25 February, 201214 yr by Retrotub

You need cams in a 1.6 AFH hybrid to get that power with the naturally aspirated lump, which don't come cheap.

They may not be cheap but a 1.6 hybrid with cams would probably still be cheaper than a G40 conversion + chip and pulley and every thing else needed to get it to a reliable 150bhp

I dunno, G40s are cheaper than they've ever been, and I got a crashed donor car for £900 9 or 10 years ago when the values were much stronger. By the time you've got an AFH conversion with ECU etc, AVY bottom end and a pair of cams from Schrick at £500ish I don't reckon there's much in it. Difference is that if the AFH setup goes tits up your chances of finding spares easily and cheaply is far higher than with the G40, and you've not got 'charger rebuilds to worry about.

You still planning on boosting an AFH? I mapped an AEA last week running 0.7 bar of boost, and that's not bent any rods yet. Will be interesting to see how far they can be pushed. TSR stopped selling the turbo kits for them back in the day because of banana rod issues, but you never know whether that's because people had been throwing bleed valves onto them and winding the boost right up.

Yeah still planning on boost mate but it'll more than likely be on the AVY bottom end rather than AFH. There are a few lupo's running boost on standard internals with good results as well so it can be done I think its just a case of being sensible with it.

One lad was running an m45 on a 1.4 16v (lupo sport), about 180bhp with just a decomp plate and that lasted at least a few years (my even still be going?) so I've got faith. I know its not exactly the same rods ect but the lads on club lupo say the 1.4 and 1.6 bottom ends are as strong/weak as each other, but there's only one way to find out

Guy just do it man! I might try source a rotrex charger

I am doing it arris, just not going to be a weekend job like yours

Got another little one on the way meaning the polo just isn't be enough any more so using that as an excuse to take it off the road for a year and make it as offensive as possible then use it as a fun second car to try and take my mind off the fact my life is now officially over

Been looking for eatons and the used market really seems to of dried up. EBay used to be full of them but now its just the odd one or two every now and then and they have doubled in price compared to what they were

Edited 26 February, 201214 yr by Mclovin

shit guy. toby got you up the duff?

Hahaha I'm gonna boost mine fuck it, then dump it in something the weight of a shoebox

come and get my mk2 shell :)

Yes I'm carrying a no arsed brummy love child

Edited 26 February, 201214 yr by Mclovin

yeah the mp45's found on mini's are getting harder to get hold of as everyone seems to be doing a conversion for their make of car now and the mini now uses a turbo.

I got my one for £118 and it was the later series one with the black rotors which are supposed to be marginally better somehow. The mini had been rear ended after 20k.

However my mate who got one about a year ago had to pay £250.

It will be interesting if the 1.4/1.6 can take any boost. The first 6psi is always the most rewarding.

I have a mp45 on the shelf in my mates workshop, so maybe we will look at that in the future. (sorry cant sell it)

Good luck with the child and the boosting antics.

Edited 26 February, 201214 yr by Retrotub

It is a great system and I'm not sure from the description above the G does. The valve mention seems to be the same as the bypass valve in function not the throttle response issue solution. However, I'm not an expert so happy to be right or wrong or halfway between...

The boost return isn't a 'charger bypass valve, cold inlet air always passes through the 'charger and gets compressed regardless. As the throttle closes, another valve in the throttle body assembly opens up, effectively bleeding off boost. With the throttle fully closed, the boost return valve is fully open. This air circulates back through a second inlet in the 'charger and through all the induction pipes in a closed (ish) loop. I say 'ish' because the first 'charger inlet is still open to air so there's a path back to atmosphere, albeit a restrictive one.

Now, I reckon if you added a secondary TB on the main 'charger inlet to seal that loop up, you could pressurise the inlet pipework more. However, I don't think anyone with a G-ladered G40 complains about throttle response, which is why no-one's bothered - and it's a different design of 'charger too.

whats an eaton charger cost now then? I've got that spare one of mine with the OEM eaton nosecone on it (allows pully to be changed as its got a nut on the end - no a pressed on pully)

we could get a lil project going on here guy!!!

Good ones seem to to for around £200 although like with anything on eBay the breaker yard people are asking prices for very shady looking items that you can almost buy new ones for

Dom on here had one he was willing to sell me for 200 with delivery miles when i was looking at charging the chevette but thats gone now

Cheers retrotub

Thanks for the info Andy. that's the thing when you stay on one make for 15 years and

then switch. There is so much ground to cover to learn even the basics.

Mclovin, please keep an update on both lots of progress.

Good ones seem to to for around £200 although like with anything on eBay the breaker yard people are asking prices for very shady looking items that you can almost buy new ones for

Dom on here had one he was willing to sell me for 200 with delivery miles when i was looking at charging the chevette but thats gone now

Cheers retrotub

id want a little bit more then half that. i was planning on making a G40 Kit to go on a PY bottom end - want to help me make the stuff up to fit on an AFH? and you can be the test dummy? split the money when we sell the kit???

hahaha - just realised the charger is in all my for sale photos lol

Good ones seem to to for around £200 although like with anything on eBay the breaker yard people are asking prices for very shady looking items that you can almost buy new ones for

Dom on here had one he was willing to sell me for 200 with delivery miles when i was looking at charging the chevette but thats gone now

Cheers retrotub

id want a little bit more then half that. i was planning on making a G40 Kit to go on a PY bottom end - want to help me make the stuff up to fit on an AFH? and you can be the test dummy? split the money when we sell the kit???

You want a bit more than half of 200? If so i'd have that off you mate

Are you looking at making bolt on kits for the 16v to sell then Kiz?

Edited 26 February, 201214 yr by Mclovin

not looking at making them- but its an option aint it. I've got a G60 throttle to go with it and other bits- think id get more as a kit rather then a charger on its own. i was going to make a plate to weld on the iet of the charger to make it a silent kit/cold side setup. - my drawings i did had the G60 throttle butterfly bit on the charger outlet linked via a cable to the G60 throttle on the inlet.

Somewhat off topic, but Mikey said 'bike carbs don't stay balanced forever'

That may be true but for 60 quid you can get a carbtune like I've got that means you can balance them whenever you like with an hours work maximum. Makes a world of difference.

not looking at making them- but its an option aint it. I've got a G60 throttle to go with it and other bits- think id get more as a kit rather then a charger on its own. i was going to make a plate to weld on the iet of the charger to make it a silent kit/cold side setup. - my drawings i did had the G60 throttle butterfly bit on the charger outlet linked via a cable to the G60 throttle on the inlet.

Agh right, well in that case your more than welcome to use the mk2 to mock it all up ect mate. I'm not a fan of silent charging, I wanna hear that bitch whine

I just have balance gauges and it takes about 5 minutes lol