Tuning suggestions

[lastyear4gt]

Now that the car is nearing completion, and I have found a place to tune it for me, I find myself wondering about any options I might want in the tune.

I know I want to alter the fan on/off temps 180 on, 170 off, I know the PCM needs to be calibrated for the LS1 MAF, remove EGR functions and tune for that and other things beyond my control, but what else?

Thinking speed limiter removed, up rev limiter to 6000 RPM, trans line pressure, skip shifts, etc.

Any suggestions?

BTW, they are using HP tuner software and a dynojet dyno.

[jackal2000]

what will they be using to "tune" it? its kind of hard to do a complete tune on a dyno which is what i am guessing you will be doing.

[AaronGTR]

The best tuning is done on the street IMO. The dynojet can only simulate certain simulations, and even an eddy current dyno that can vary load resistance still doesn't add rolling and wind resistance in the equation which can affect cooling and such. You usually only use the dyno to fine tune WOT. Unless they tune your car on the street first it will only be a rough tune.

Also, can HPT import MAF values from another MAF directly into the MAF table? Better make sure first, otherwise adjusting for the LS1 MAF could be time consuming and drive the cost up. I'm only asking because I don't know everything that HPT does, but from what I've been reading on other forums they go about tuning fuel and such in a very funny roundabout way.

[Sprucegagt]

If your using a 180* tstat, then I wouldn't have your fans turn on at 180. Instead let it rise to 185* then turn on fan 1. Once it gets to 188* then turn fan 2 on. Turn them both off at 180*. During the summer it will be very hard to get coolant temps below 180*.

[lastyear4gt]

The best tuning is done on the street IMO. The dynojet can only simulate certain simulations, and even an eddy current dyno that can vary load resistance still doesn't add rolling and wind resistance in the equation which can affect cooling and such. You usually only use the dyno to fine tune WOT. Unless they tune your car on the street first it will only be a rough tune.

Also, can HPT import MAF values from another MAF directly into the MAF table? Better make sure first, otherwise adjusting for the LS1 MAF could be time consuming and drive the cost up. I'm only asking because I don't know everything that HPT does, but from what I've been reading on other forums they go about tuning fuel and such in a very funny roundabout way.

Uhoh, I thought it was HPT that you could directly import MAF tables with. I better do some research. Probably out in left field, but does anyone know if there is anybody near toronto/ontario that tunes with the DHP?

[lastyear4gt]

OK, well I got a response on the HP tuners site and this is what they sent me:

Also, when Im calling around to potential shops what am I wanting to ask. If they do a street tune before dyno tuning? See this is frustrating because I want to get the DHP, but a laptop and DHP program is not in the wedding budget! Hopefully next year.

[AaronGTR]

Yep, that looks right. Those numbers should be grams per second of air and they correspond to a Hertz frequency in the maf airflow table. In the powrtuner you open up the table and there are 81 cells with Hz values from 1500 to 11500. I counted 80 numbers in that .txt but I might have missed one. It should be right though, the highest number will match up to 11,500Hz. If HPT has an import function they should be able to just copy all those numbers to the table instead of entering them one at a time.

And yeah, I'd ask them if they do any street tuning.

[lastyear4gt]

OK, I found a guy that seems to really know his stuff. He does alot of turbo 3800 and a couple SC GA's with the RSM kit. He only does street tuning, but can do dyno AFTER the street tune for an extra price.

He was saying that the tuning with my stock injectors is going to be very limited. He is suggesting that I will make much more power and be able to go with a real agressive tune with bigger injectors. He was suggesting 42Lb/hr injectors. But he said if I want to save a little money (which I NEED TO) he has GTP injectors with about 30,000Kms on them he'll sell me for $150. He assured me that the 36LB/hr injectors should be more than enough for quite a while.

Is he pitching me a line or should I be getting injectors at this point. Oh, and are the injector harnesses the same as the GTP?

Opinions, NEED HELP!!!!!!!!!!!!!!!!

[AaronGTR]

Oh yeah, you'll definitely be better off with bigger injectors. Think I told you that already somewhere ;). Stockers will work but you'll only be able to run 6-8psi of boost and they will be basically maxed. The GTP injectors would be plenty for you. Either way though if you get those or 42's you'll have to change the harness because they use bosch clips and you have delco clips. You can solder new clips onto your stock harness, or you can get a harness from a 96-99 3400 and change the cam sensor connector.

[lastyear4gt]

Can you elaborate on the cam sensor connector situation? I cant remember off the top of my head what thats about.

[AaronGTR]

The 3400 engines have used three different cam sensors over the years and they have different connectors on them and different lengths of wire and connectors on the leads on the wiring harness. The years were 94-99, 00-02, and 03-present. I know the '03+ sensor has the connector built into the end with no wire lead on it. Also some of the wire positions were switched around between years. Basically if you use a '99 harness, you'll have to lengthen the wires and add an '03+ connector, and see if someone with a 99 manual can check the connector end views and give you the orientation of the wires so you can hook them up properly. It's easier than it sounds. :)

[lastyear4gt]

Ill just go back to the dealer I worked at and get the schematics. I remember now that my cam sensor has the connecor right at the sensor, no lead comming off, so Ill just cut off my stock harness from my injector harness and solder it to the 99 harness.

I just bought 42.5lb/hr injectors and harness from harvester45.

[lastyear4gt]

Just thinking today, am I gonna need a bigger fuel pump to run these injectors, or can I hold off on that. And if so how many lph do I need?

Keep in mind I am driving this car from toronto to key west Florida in the fall on my honeymoon, so reliability is a must. If the pump is liable to burn out on me with the bigger injectors, Ill just put one in it, but if I can at all put it off I will.

Oh, and where would I get a HP fuel pump?

[AaronGTR]

Nope, stock pump will be fine.

[lastyear4gt]

Do I have to use a special kind of injector clip for the 42lb injectors, or just a stock 99 clip will do? There isn't a chance my stock clips will do is there?

[AaronGTR]

Your stock 2004 connectors are delphi so those definitely won't work. Stock '99 connectors are bosch style so they will work just fine. You don't need anything special... just one or the other depending on what style injector you're using.

[lastyear4gt]

No,no I mean the retainer clips that hold the injector to the fuel rail. I know the connectors are different, the injectors I bought are comming with the 99 harness, just have to solder on the 02+ cam sensor connector.

[AaronGTR]

oh, ok. Yeah, they should work fine. The fuel rail is the same and the injectors have to have the same size end to fit it. I used the same clips on both my injectors.