Fabulous_omelet

Hey guys, this coming weekend I'll be picking up my new motor for my car, rebuild due to the bad Leakdown failure of my current one. It's all aftermarket forged internals, cp, bc, acl bearings, sleeved, full supertech valvetrain, etc.
Now, this motor is built to be boosted in the future, with a 10:1 comp ratio, and I'll be running it n/a, during the break in, and before I buy a turbo setup for now, while paying off some Debt in this motor. It's one of the two cars I drive regularly. Realistically, it will probably be a year before I have the turbo set up actually on the car.
My question is, being a built motor, with a 10:1 comp, do I need to tune the car as is for now? It's a 2000, so I have one of the more rich running AP1 ecus. Only other mods are an Invidia q300, 70mm test pipe, and a ghetto rigged intake, which will be replaced with something better when the motor goes in (Comptech, k/n) If anything, I'm thinking running it as is will just cause it to run extremely rich, which is not dangerous, but inefficient. The guy building the motor for me said to tune it to be carefully "because all motors will run different".
What do you guys think? I don't need advice on how to do the actual break in itself, or what to do with that, I just am midly concerned now that I may need to have it tuned sooner than I thought.

Habitforming

Yes you should have it tuned. It's a completely different motor now. Running too rich can indeed cause issues, if it's rich enough. Just my 2 cents.

Fabulous_omelet

Do you think using a vafc, or a simple fuel controller like that would be sufficient? I really am trying not to have to buy a full standalone, but I will if I have no choice.

AE_Racer

It may be sufficient but you will spend the money on a piggy back, then later on you will need a stand alone ecu for the turbo setup.. Buying a bandaid for now will cost you more down the road.

cheddaboy

Holy shit Im in the exact same boat lol. Brand new motor built with forged internals, 9:9.1 cr and aftermarket intake and 74mm tb. I will be using my existing Comptech SC on this motor after getting it rebuilt. Which should be close to a year from now lol. Anyways, I was told by many to get a base tune so that you don't risk messing up the new motor "because motors run differently". I have a stand alone ecu I will be using already. Some said to use the OEM ecu and fpr but I'm just going with the tune. I'll keep you updated though.

liquidgsr

Yes your definitely going to need to get a tune. You can't use a factory ecu to run a motor that doesn't have the factory internals anymore. I would just get the stand alone now.

Fabulous_omelet

I just spoke to the shop on the phone that will likely be tuning it in the future, and has worked on multiple S2000s in my area, and built motors for some. They have told me with stock cams (which it has) and stock injectors (which I will be using), that it will be fine to use the stock ECU. Now I'm utterly confused, as I've gotten mostly responses on here recommending to tune it, and varying responses everywhere else.

s2000Junky

Don’t any of you guys run widebands? That will tell you exactly where you are and if you need to make some fuel corrections or not. On a lower then factory comp motor, the stock ecu is totally fine, so its not a matter of tuning timing, its all about the fuel tune. Chances are 50/50 that you are ok as is or need some fuel enrichment or leaning somewhere in the band. Idle/closed loop (35% throttle opening) will be self corrected by the stock ecu targets, so fuel washing or running lean wont be an issue there, but its open loop/WOT you need to make sure your fuel is correct. So you need a wideband monitoring to check this. You can run a adjustable fuel pressure regulator if you need to add or subtract fuel, and or with the addition of a vafc if you want a more refined fuel tune.

JuicedS2K

Definitely Standalone. You will have great tuning capability for your new motor and you will need it later on anyways.

Fabulous_omelet

Okay, I understand that the best option is a standalone for both now, and future use, but as I stated at the start, money is tight for the next little while, and I don't have an extra $1500 to throw at it all at once for a few months. S2000Junky seems to be saying what I'm thinking, which is that with a wideband to monitor and a way (afpr) to check and correct the fuel system, would that not do what I need it to for the time being?