Velocity stack, ITB ideas.

[zach44102]

Me and a couple of my friends have thrown around the idea of Bike carbs on a sho motor like people do with the 4ag's in the rwd corolla's and i think it would be pretty crazy. Something way out of my abilty to do. But i pondered on the idea of velocity stacks on top of the heads and keeping the fuel injection system. So would there be a way to delete the IAC/MAF setup and properly tune the motor to opperate correctly without it.

 

[Eric VerValin]

Look around for info on one of the salt flat racers.... I remember seeing a carb on a SHO motor. Thing was fast as **** too IIRC. Offroad would know something about this I bet.

 

[zach44102]

Yes i have seen pictures, but not interested in carb'ing a sho motor. Been doing sone research for a couple hours and i have found universal ITB's with either a 40,45,50mm bore. But holy jesus are they exspensive.

 

[Eric VerValin]

Well either way they had to get around the IAC didn't they?

Expensive, but on a big block OMGWTFBBQ. Might work wonders on a SHO motor? Who knows... what I do know is that it cost money to go fast you know.

 

[whiteman_01]

Supposedly, a SHO friend of mine saw one like that here in mn, built by courtney truck service. Didnt get much info on it though, just had the stacks through the hood.

 

[vortex2450]

The problem is giving the ECU a way to meter the incoming air to adjust for fuel trim. To run ITB's you would probably have to strip all the sensor BS off the SHO and go with a custom fueling set up, I'm sure there are forums and groups of people who specailize in converting MAP/MAF EFI engines into ITB set ups.

The first idea that poppped in my head was having 6 "mini" meters to detect airflow after each TB and finding a way to program them into a workable logic program.


-Josh

 

[kevinspann]

ITBs in place of the butterflies essentially, without having any of the tanks. Not sure how idle would be worked. Speed density system will do away with the MAF. Megasquirt for engine management.

 

[AREA 91]

ITBs in place of the butterflies essentially, without having any of the tanks. Not sure how idle would be worked. Speed density system will do away with the MAF. Megasquirt for engine management.

Here's your answer.

 

[SHOtime2511]

Megasquirt and a GM 5 bar map sensor,convert to speed density.
You would need to construct your own wiring harness from scratch.

 

[SuperHO]

oh my God how wicked would that sound?

 

[zach44102]

Ok, i hear everybody talk about MS. But how many people are actually using this?

 

[3d914]

zach,

I've used it successfully on a Porsche 914 - 2.0L flat four. Here's a link to plenty of examples. The concept they're talking about here would be manageable by MS-II. The ITB setup was one of my options for the 914, but decided to stay with close-to-stock setup.

Certainly sounds doable for the $$.

 

[Shoaz]

Remember that a lot of what makes a SHO motor a SHO motor is the dual intake runners and butterflies and volume-matched tanks. When you do away with that you essentially commit to getting a lot of the performance some other way. Fixed velocity stacks and ITBs suggest you're tuning for a specific thing, like peak hp, rather than a fat torque curve, which is a lot of the value of the SHO motor.

So expect greatly reduced low end torque. Elsewise I don't know why it would be done.

 

[kevinspann]

Actually he's right. At that point, if you really want ITBs on a V6, go with a Duratec. All aluminum....

 

[SHOmethewayhome]

I remember a while back seeing a guy run ITBs on a KA24 motor, and it was such a huge headache for him compared to the power gain from it.

looked and sounded **** though.

go look at EFI motorbikes. they have ITBs, and DOHC heads.

 

[SHOtime2511]

Just boost it.

 

[TwistedD85]

To make the car remotely drivable you'd need to make some pretty long stacks, take the length of the short runners and the length of the long runners and meet somewhere in the middle. The shorter you make the runners the better they'll be for the top end, but your bottom end will suffer. I believe the same can be said for the other way around. Not only that but to make a good functional system you have to figure out the proper butterfly diameter and location inside the length of the horn. But really any way it goes it'll at least sound awesome.

 

[zblackbeast]

Go find an e34 m5 and figure out how BMW made it work.

 

[zach44102]

I was just curious what it would take to make it work. By no means do i think i can do it. Thank you for everybody's input.