To increase my boost i need to decrease the s/c pulley or increase the crank pulley , with my current setup i don't have much i can take off the s/c pulley as its about 2.9" and the gap left between the belts from the tensioner set up isn't much either so my thoughts are on increasing the crank pulley so rather than getting a custom cnc pulley is it possible to use one from a different model ? my current set up is a eaton m45 on a 1999 2.0l elantra, i think the crank pulley is 5-15/16" x 1-3/4 from what I've read so maybe a 6" ?

 

You can't really muck with the crank pulley side unless you want to drive all of your other accessories faster and possibly cause damage. you're Alternator, AC Condensor and Water pump would all end up being driven faster if you increased the crank pulley size. A larger crank pulley would also add mass/weight (unless you had it custom made) which isn't good in a rotating assembly.



Go with a smaller supercharger pulley. You'll run the risk of belt slippage, but you can build guides to keep the belts on track.

 

a 2.25" s/c pulley has been used on our cars-... look up balbains324 and larryinkc for more info.



how much boost do you have now?

 

I only got 6 psi atm running 305cc injectors and a walbro 255l fuel pump, i'll settle for 8 psi until i do some more engine work . I've got a tigerlily 65mm throttle body going on soon.



So my thought of using a crank pulley from a vehicle that has a larger diameter than the elantra was not to use the oem but a lightweight/underdrive so the inner would then therefore be the same diameter as the oem elantra but the outer would be greater ?



Does any one know what the different hyundai model crank diameters are?

 

If you just have to change the crank pulley, you could also get underdrive pullies for the engine driven accessories so they would go back to spinning normal speed when the crank pulley is larger. I'd see what happened with a smaller supercharger pulley first, though.

 

Some good news some bad news - From the dyno the new 57mm pulley got me 9.5 psi and 240 hp @ the flywheel with the bigger 65mm throttle body, thats the good news the bad news my current engine wont support the extra as such. Basically got too much boost to use as hp , timing had to be retarded to stop the pinging [detonation] so i need to make a few changes when i get a rebuild done to get the waiting hp.

But it sounded awesome on the dyno and a few surprised heads turned

 

what are your other supporting mods-???



colder plugs?



exhaust? headers? port and polish head? those should drop the psi but allow for more hp. i don't think that'll solve your detonation issue though. water injection would intercool it though and it would be easy to rig up before the bbtb-... also if the coating on your rotors is chipping off (like some of the earlier eaton m45 units did) the water droplets would allow for a better seal to the rotor/walls of the m45-... all w/o having to build your engine!



what engine management are you using?



is the supercharger being driven by the outermost part of the crank pulley or the one for the ac?



i hate to suggest singh grooves but iirc "bal" included them into his setup and didn't have any knock w/ a 2.25" pulley but he had a uk ecu.



i envy/applaud you for doing this. i've been stalking your photobucket as i want to sc my tib-... i definately have been paying close attention to your custom intake manifold.

 

Singh grooves next time you have the head off!

 

Thanks m8



Original stock engine atm

Auto tranny

BKR6ES-11 plugs

4-2-1 extractors 2 1/2" to FG XR6 cat [local aussie ford v6 cat] back to standard system via straight through sports exhaust[made in u.s.a by thrush]

Haltech Platinum 500 ecu

65mm tiger lily throttle body

Pod filter

crank via A/C pulley



I do have a crude water injection kit in the shed i could play with, as this project wasn't about building a monster and being an auto I'll probably use what I've got but when i do an engine rebuild i might try some options like either a thicker head gasket or go with the 1.8l pistons and rods to lower compression.

 

that's a nice boost w/ a full exhaust!



your m45 is working near it's peak to do so. it's most likely spinning somewhere around 15,500 rpm and maxes out @ 16k. the crank side that you are using is roughly 133mm miata pulley chart use that to get an estimate of where you're at. matter of fact the m45 was very popular for the miata crowd so if you wanna do some serious m45 research that is where to go.



i wouldn't mess w/ the 1.8 pistons/rods or the decompression gasket. the 1.8 pistons/rods would drop your CR too low and the decompression plate is quite a gamble. i'd have a speed shop rework the combustion chambers in the head in order to drop the CR a bit. i still say stick w/ water/meth injection (especially if you already have a crude kit)



i wonder why your boost level is that much higher than larryinkc who has a very similar setup but off the larger side of the crank pulley?