The Mega Supercharger 4AGZE thread, using twinscrew charger

[RonRob]

This is the Opcon OA3150 1.5l/rev dyno for a 4AGE race engine running on methanol without an intercooler...



The price is good, but it comes with a nose extention (I need the short version) and the phsical dimensions are just a bit more than I would like. So for the moment I am figuring on using the smaller Sprintex.

Cheers... jondee86

That is one impressive 4a! I too would like to see the power down low, but I figure it's built to stay in the upper revs.

Getting a flush face plate can be found fairly easy for that 1.5. The Sprintex line looks really impressive and can't wait to test them out.

Ron

[jondee86]

Batley Racing is a private outfit operating out of New Plymouth in NZ And Anthony loves his midget cars enough to invest the time in building this awesome two-piece 4AG block. I posted the pics because the work on this thing is superb. But I don't think you will see a lot of them around, as I think there was about 80 hours worth of CNC machine time in making this one, and Anthony won't be selling them to the opposition

Cheers... jondee86

[trdee]

What I would give for a billet block....

[jondee86]

Hey RonRob... I'm just starting to do a bit of a setout drawing for fitting a charger in my engine bay, and suddenly I can see why you have had to go to so much trouble to connect things together. There is not a lot of room if you want to leave the original RWD water pump and pipework in place on an AE86. FWD/MR2 water pipework is a lot different, and I would really like to keep the RWD setup, as that makes the installation a simple "bolt-on" job.

I'm looking at using a 100mm nose extension to push the body of the charger back past the radiator connections, and that does not leave a lot of room between the intake of the charger and the firewall junk. Kind of a packaging nightmare, and I suspect RHD has even less room than LHD. This is going to keep me busy for a while !!

Cheers... jondee86

[RonRob]

Yes, I understand your frustration. Your inlet is your everything. We have in cad a design for the ae86 that puts the throttle body over the blower with the TB facing the pulleys and moves the bypass valve to the side. Allowing us to run our massive TB. Going to be made out of solid billet aluminum like the other parts. Pm me if you need anything.

Ron

[jondee86]

Scored a set of 0.5mm oversize genuine 8.9:1 pistons and rings at a good price



And a GZE head with fuel rail,injectors and cam covers.



So I will be able to see if the intake ports are any different from the N.A. smallport head. Might have to rebuild my spare engine with the GZE pistons and shoot for 10-15psi sooner rather than later

Cheers... jondee86

[jondee86]

I was thinking about what would be an appropriate size throttlebody, and wondered if there was any rule of thumb? Is bigger always better?



In particular, is there a danger of losing the ability to smoothly modulate power if the throttle is too big and a small spindle angle produces a large percentage throttle open area? That is, do you get a "lightswitch effect"?

I was thinking about this today while enjoying the quad throttles on my N.A. 4AGE

Cheers... jondee86

[TERRA Operative]

You are correct.
You can counteract the on/off effect by ofsetting the pulley that the throttle cable wraps around so the spindle to the butterfly is not central.
This creates a gearing effect like a cvt sort of thing so it opens slowly at first but as you open the throttle, the butterflies open faster and faster to wot.

[jondee86]

Thanks... I was thinking something along those lines might be necessary.





I reckon I could do something like this guy did for his bike. Made a few plastic ones until he got the cam profile that he liked, and then made a metal one. Although modding a standard quadrant might be easier.

Cheers... jondee86

[jondee86]

I was thinking a bit more about the size of these things, and it seems to me that there is a bit of a catch 22 situation going on ?



If you increase the size of the throttle to reduce the pressure differential across the throttle (custom intake pipework), then you are likely to reduce the control authority of the butterfly even more. That is, the throttle will be even more sensitive at small openings.

I'm thinking of looking for something a bit larger than the 55mm dia 4Age N.A. throttle... and had 65mm dia from a larger displacement Toyota in mind. Does this sound like a good idea, or would 60mm dia (or even staying with the 55mm dia) be a better move ?

Cheers... jondee86

[trdee]

can't comment. boobs are overwhelming brain

[tomvale13]

..... why have I never come into this thread before..

[trdee]

the question is whether you think the throttle body is restrictive or not enough to warrant going to a larger TB? there was definitely a gain going to the 4AGE throttle body. not sure how much more you would net from anything bigger.

could do some flow calcs to see what velocity you are getting through the different size throttle bodies. iirc 3m/s was considered the most "economical" flow rate in engineering, but whether that is a significant factor in this application i dont know.

short of doing some serious maths, i can only suggest experimenting with various setups on the dyno and seeing what difference you get...

[RonRob]

I was thinking about what would be an appropriate size throttlebody, and wondered if there was any rule of thumb? Is bigger always better?



In particular, is there a danger of losing the ability to smoothly modulate power if the throttle is too big and a small spindle angle produces a large percentage throttle open area? That is, do you get a "lightswitch effect"?

I was thinking about this today while enjoying the quad throttles on my N.A. 4AGE

Cheers... jondee86

Like your style Jondee. Go with the biggest one you can find, you don't seem to have a problem with the biggins that for sure. And remember, the bigger you go the more chance you have of sucking something thru the tb like your hand or a small child..


Ron

[RonRob]

Scored a set of 0.5mm oversize genuine 8.9:1 pistons and rings at a good price



And a GZE head with fuel rail,injectors and cam covers.



So I will be able to see if the intake ports are any different from the N.A. smallport head. Might have to rebuild my spare engine with the GZE pistons and shoot for 10-15psi sooner rather than later

Cheers... jondee86

Please put me in contact with the dealership you guys get your small port Ze gear from. My contacts are all dried up. I may be able to get away with a hone so standards is what I have on my mind.

Thanks in advance,
Ron