ITB w/ megasquirt questions

[airedout]

Well, since my deal on the KA24 i was going to buy fell through, im looking at building a hot L16 and doing an ITB setup on it. I was wondering what the most common throttle body setup people are using is. Most ive seen use 600cc or 750cc motor cycle throttle bodys. Also with the electronics side of it im pretty much stumped. Any tips would be great, or sites with info would be kick ass. Ive heard the megasquirt setup is the way to go, is this true????

[kiznook]

try lookin around over on nicoclub, you should find a couple of itb'd KAs, slodat should chime in soon too!

[slodat]

Good question! I have am building an ITB/MegaSquirt L series. I am currently using a JDM L18E intake manifold - until the ITB manifold is finished. My fabricator has a huge backlog.

 

Anyway, in my opinion, Megasquirt is the way to go. Essentially, this is what you need to do the ITB/MS L series:

• Megasquirt ECU. I recommend MSII with a V3.0 circuit board. DiyAutoTune is where I buy them. I am very happy with their service. They contribute a lot to the Datsun/Nissan community with tech writeups on how to make things work on our engines. You can buy an ECU kit for $247 or assembled for $410.
  
• Relay Board - I highly recommend this. It makes the wiring MUCH easier. I have a friend who has had a lot of trouble with his MS conversion and I think the relay board would have saved a ton of wiring trouble. It is truly easy with this. They are available as kits or assembled.
  
• Wiring - DIYAutoTune sells a nice wiring bundle. The wires have labels printed on them. Makes for a very serviceable system.
  
• Sensors - IAT (intake air temp), CLT (coolant temp), TPS (throttle position sensor), O2 (oxygen). All of these are very common off the shelf parts. I recommend a wideband O2. It makes tuning possible.
  
• Throttle bodies - the 750/1000cc GSX-R throttle bodies are perfect for an L series and can be had inexpensively. If you can fabricate a little and weld aluminum, making the intake and mounting up the ITB's is pretty easy. The stock injectors may be big enough for an L16. Upgrading injectors is dirt easy.
  
• Ignition - you can use points, EI dizzy, a ton of other things, or EDIS (distributorless). I did EDIS. Works great. Very simple. VERY clean engine bay.
  
• Fuel system - you need a EFI fuel pump, FPR (fuel pressure regulator) and a return line. Sky is the limit. My fuel system ended up being about $600 because I ran all AN line and I wanted the fuel system to be able to support a turbocharged engine.
  

 

There is a TON of info on http://www.megamanual.com/

 

I am happy to help how ever I can. This is not a cheap thing to do. But it is also not apples to apples with a KA swap. Fully and I mean FULLY programmable engine management system is a wonderful thing. I have it controlling all sorts of little things in the car to make it the way I want. You can also have a VERY clean engine bay with a setup like this... ;)

 

I should fire my car late this week/early next.

[airedout]

Wow, thanks a lot man. That really put somethings in prespective for me. Im really wanting to do this down the road. Id like to keep my truck as classic as i can with the datsun motor, but with a few modern touches and i think an ITB setup would be perfect. Do you think somewhere around 220whp is possible with a built L16 with an ITB setup??????? Thats kinda what i am shooting for, 220whp would be fun in my low little truck.

[datzenmike]

Wow, thanks a lot man. That really put somethings in prespective for me. Im really wanting to do this down the road. Id like to keep my truck as classic as i can with the datsun motor, but with a few modern touches and i think an ITB setup would be perfect. Do you think somewhere around 220whp is possible with a built L16 with an ITB setup??????? Thats kinda what i am shooting for, 220whp would be fun in my low little truck.

 

I'll say this now Dwight, IMHO, The L engine (any size) is realistically, good for about a 50% hp increase with normal aspiration and a reasonable build up. With much work and money and parts and money and then more of the above to insure that everything is strong enough and oiled enough and cool enough that it stays together and not become expensive scrap metal, you could maybe get up to double your starting hp. I know you'll say: ... we all know someone who got more hp than that, but what did it cost? It's a case of diminishing returns. You will quickly get to a point where adding another 15-20 hp will cost 5 times what the first 20 horse increase cost you.

 

I guess it sounds like I'm raining on your parade, and I guess I am, but shoot for a 50% goal. Perhaps your build should include all that is needed to support a turbo addition at a later date. Now there's power! You might consider an L20B engine, 25% bigger return on anything done to the motor and it looks like an L16! Slodat's L18 is a good choice, bigger, but still you can rev the snot out of it. Hey, no offense, it's only an opinion, and everyone has one. Best of luck with your build.

[slodat]

My turbo engine is an L20b. When I build an engine it will be higher displacement.

 

I know for a fact that 225whp with an L16 is a $35k Rebello full race engine (dry sump oiling, etc). If you want more power, do an LZ2.3 or 2.4 with a turbo. My plan is to do a hybrid LZ for the turbo engine I will have built. It is 50% more displacement.

[Icehouse]

Just leave the old tie rods and don't rebuild the kingpins 125 to the ground will feel like 225 :D At collision specialties there was a carbed ka24e with 200rwhp. Maybe you should keep you eye's out for another one. Do ITB's instead though :D

[BEEBANI]

Dwight, get a ka! You'd be the talk of town, we haven't seen a 521 with a ka have we?

[kiznook]

hmm...KAE with dual mikunis and a modified L-series valve cover.

[slodat]

I'm with Dwight - build a bad ass L motor to keep the engine bay looking good. There is no cleaner engine than an L motor without a dizzy!

 

I'm willing to bet I can get 200whp with my turbo L20bet. When I build the turbo motor, I'm thinking I will get 250+. It will be 2.3-2.5L, built for turbocharging and built for a lot of boost - 12-15#. My engine builder is saying in the range of $3500 for a nice turbo engine build that will last and be very streetable. Forged JE pistons, brand new crank, big valve head, o-ring head, etc.

[airedout]

Well if thats the case, i might be looking for an L20 or a KA24e. I deff want at least 200whp (should make the truck move right along). Either way I go (L16, L20, or KA) im still planning on messing around with the ITB's. It sounds like fun, and it something i havent done before so the plan is to learn it very quick. :D I really would like to keep the car N/A because every turbo motor ive ever played with is too damn finicky to daily drive, plus my lack of space problem.

 

Thanks for all the info guys!!!!

[slodat]

200whp from a N/A 2L engine is a TON of power. With a turbo or supercharger, it is dead easy. Build a big L series - 2.4L and it gets a lot easier.

 

ITB's and EFI are the only way to do it!