Engine Management options for Non-Turbo? (S5 SP)
 

I rescently built a S5 NA motor and did a large streetport during the build.
After install and longblock assembly I could get it to idle, but after about 30-60 seconds it wanted to surge and die. After numerous adjustments to the throttle body, TPS, and installing S5 turbo injectors and an FD fuel pump the problem was still. I installed a new TPS and set it to FSM spec and the problem only got worse.
The only way i could get it to run better and idle was to set the tps way out, tricking the computer to think the throttle was out, and giving the engine more fuel in compensation for the much more than stock amount of air the engine is getting. I also might add I have a ported and modified throttle body on the engine now as well as 3" aluminum intake piping, and emmisions delete.
So after all of this. I came to the conclusion that I am in need of either some sort of piggyback system that will deliver more fuel to my Large streetport 6 port engine or a stand alone system.
What are my options?

I do have a HKS F-CON, but its for a S5 TII.
I was thinking along the lines of a SAFC.
Would I be able to tune in more fuel with this?

your giving it to much fuel as it is. n/a dosnt need bigger than stock injectors/fuel pump for your situation. Go back to stock fuel system and get a s-afc to do some slight tuning. OR if you plan to go all out in the future then get a standalone ecu/wideband +whatever else installed and have a pro tune it.

go stand alone ems. dont fiddle with the stock shit.

a haltech sprint RE is a good choice.

Rtek 2.1 is an option too. www.digitaltuning.com

I think Haltech Sprint RE is a bit much for an N/A build considering you get the same (pretty much) performance out of an Rtek 2.X. If you wan't to go full standalone I'd suggest it but an Rtek will give you better tuning options (safer) than a piggyback for WAY less than a stand alone.

Rtek is probably your best bet.

this is completely erroneous.

a stand alone is light years above what a rtec can offer, and the fact that you can use a sprint re with a plug and play harness? null an void on the rtec.

A Haltech platinum sport will offer a bunch of features you don't need for an n/a engine and will cost a large percentage of the vehicles resale value. The Rtek can control fuel (including cranking fuel), timing, aux ports, and VDI basically by making adjustments to the factory computer. It won't require anywhere near the amount of time and money investment.

i was talking about the sprint RE which is tons of money cheaper.

haltech would make this go away, but even then break out the brake kleen, you got a vacuum leak.

Agreed. We don't need a computer argument. Each have valued "opinions". Anyway agreed on vacuum leak. On a cold motor, you kind of "need" a vac leak. helps the idle run higher with that extra fuel. A BAC valve like I use is a glorified vacuum leak. When cold if the settings are right, you're good. When warmed up they may not be right and the car will die. Surging is an easy way to determine vac leak.

However, some have said too much fuel. Agreed again. FD fuel pump and 550 cc injectors are overkill for an NA. Maybe a BP would require that.

To much fuel?... Than why would it be running better when giving it MORE fuel?

Doing some research on that this weekend. From what I understand this may be just what I am looking for.

I will be checking the motor over this weekend for vacuum leaks. I am not currently running a BACV, however I did temp. hook it up to see if it would make a differance and none.

I dont know. but either way you dont need upgraded injectors,fuel pump or fpr.

A standalone is a great thing but unless you need all the little extra power you can get or plan on turbo in future then i wouldnt bother. A s-afc is fine for you. Rtek is great but meh you just dont need it! Is this a daily driver, track car or both?

Right now it is just a weekend warrior. In the future this motor will be going in my GSL-SE. I have a turbo motor for this car that is being built next spring.
How much can I tune with the safc? It looks like I can tune more with the Rtek.
The main things I am wanting to tune are obviously air and fuel. It would be nice to have the 6pi and VDI tuneable as well.
I might also add that this is a very large streetport. Infact It was ported about as far as possible without going overboard.

The Rtek looks cool and sounds like a great idea! However, why are they using palm os for tuning? :scratch: Talk about nostalgia. :banghead: I want my iPhone or macbook for tuning. Preferably my iPhone though.

Heh, good luck finding tuning products that work with an iPhone or Macbook.

Almost all tuning software is Windows only, and for good reason.

Now, the Megasquirt has several Java based tuning programs that work on most Unix based platforms. Not sure about the iPhone though, considering it really doesn't have any I/O and is a closed platform.

Really, the tuning solution you look for will depend on want you want to do. The RTek will do the job just fine, but a full standalone will go farther and allow you to upgrade in the future if you suddenly decide that you want to go to forced induction. The disadvantage of a full standalone is that you need to start from scratch: wire it into the car, then tune all the maps yourself.

Thanks for chiming in here Aaron. I always value your opinion and knowledge.
Looks like for now I will be going with the Rtek. Possibly in the futue with the turbo I may choose a stand alone unit.

A couple pics of the car.

This can also be a big advantage, as you are starting fresh - no 20+ year old brittle wiring, no more AFM etc.

One piece of advice - whatever you get, it's a HUGE help to have local tuning support! Discussing what standalone or piggyback is best means nothing if you don't have anyone that can tune it properly. Yes, you can learn to do it yourself, but an experienced is worth their weight in gold.

I put a microtech on my '86 NA and it's great - although I have moved across the country since I installed it, and now I have no local shops that can tune it for me which is frustrating.

Agreed! :icon_tup:

I bought my Haltech Sprint RE from Chris Ludwig when he was having that group buy sale on all Haltech stuff.. I picked my Sprint RE brand new with brand new wiring harness for a tad bit more than you'd spend on getting an Rtec 2.X on your existing ECU. :) It's limited on outputs on my cosmo engine, but it's okay. On an N/A like yours, it would give you great results!

plus not to mention you have a brand new wiring harness, plus not to mention all the sensors are gm based. no more buying expensive Mazda units.

o well. guess people like the rtec. and 20 year old harnesses, and 20 year old sensors that cost an arm and a leg.

I am actually looking into this as well. I would like to use something that I can eventually tune my turbo motor with.

It'll definitely tune a turbo motor. I've got a T04S on my 13BRE so I'm definitely one testament that you can tune it with a turbo engine. Only thing is, like I said, it's limited on outputs. A lot more options than Rteks though.. :) It's got one dedicated thermofan output, one dedicated tacho output, and 2 generic outputs that can be configured. Spend an extra $60 on the boost control solenoid and it will control boost. It doesn't do closed loop boost control but it'll still work. I'll be using my 2 outputs for AI and boost control.

You can also get GM water temp sensors and air temperature sensors with metric threads on them. My water temp sensor screwed right into the stock thermo sensor bung.. and for the air temp sensor, I just dripped/tapped the stock location and it fit right in