Tune or No Tune??? Help!!!

[Mr. 7M-GTE]

Ok, so I'm dropping in 550's and a Lex AFM. I'm waiting for tax return time to get a SAFC and wideband and try to tune my 7M-GTE. My question is this; Is it safe to drive my car with just drop in injectors and a Lex AFM w/o a tune? My other mods are BIC Test Pipe & Divorced DP, Blitz Nur Spec Cat-Back, DM CT-26 57 Trim, Apexi Power Intake, and a Godspeed FMIC. As my MK3 is my daily driver, I am kinda concerned. Thanks for the help!

 

[CajunKenny]

Without an upgraded fuel system, there is no benefit in doing this.

What's your head gasket/head bolt situation?

 

[Mr. 7M-GTE]

I've got a OEM gasket and ARP studs...I just hit boost/fuel cut from time to time and thought I should start upgrading the fuel system. I will be putting the 550's and Lex AFM in, I was just curious how the car would react with just those items alone w/o a tune. I know it's gonna run rich as hell most likely.

 

[OfnaRcR4]

Look at my build thread on the last page to see how it runs. You really should drop a walbro in too though. Also mine was done with the evo 560's with the 4 ports so it might be a tad different than yours.

 

[Supra0089]

Get an afpr, fuel pump upgrade, and a wideband before the safc IMO.

Read my current setup on my sig link if you like. I'm running 50 trim, fuel upgrades (550's with lex afm), and support mods and I run great w/o tuning or a piggyback.

 

[gottadiesel]

I know it's gonna run rich as hell most likely.

Yes and no, if you are still running a stock pump, it will most likely not keep up with the 550 injectors, therefore it may run rich initially, but as you work up into the higher RPMs at WOT, I would think there is a risk of running lean.

Bottom line is that if you are not running a WB sensor yet, I would not do anything else without one, it will tell your story for you and perhaps keep you from destroying a motor...

Personally I would wait until you bought all of it and did it all at once, but even after all of that, you may find that you have to be careful how hard you run it, as you are likely to run out of fuel with stock pump. Just my opinion and $0.02 worth...

Supra0089 - beat me to it and yes what he said is very true... I would not do it without the Fuel system mods, but if you were going to try it anyway, I would not try it without the WB

 

[CajunKenny]

I've got a OEM gasket and ARP studs...I just hit boost/fuel cut from time to time and thought I should start upgrading the fuel system. I will be putting the 550's and Lex AFM in, I was just curious how the car would react with just those items alone w/o a tune. I know it's gonna run rich as hell most likely.

Fuel cut is saving your engine. Installing the Lex/550's may get you around fuel cut for the time being; but, then what? BHG...?

Like I said, at this point in your setup, there's no benefit in doing this.

Do as others have suggested and then you'll be ready for some tuning. Otherwise, keep your car running by leaving it the way it is because we don't need another BHG thread.

 

[Devin LeBlanc]

Im running 12lbs on Felpro head gasket with ARP's.. Stock injectors, AFM, 2.5 inch hard pipes, 3 inch intercooler, NA-T setup with SAFC.. With the stock AFM screw modified and the SAFC for tuning, everything is good no fuel cut

 

[CajunKenny]

^And that's how it should be done.

I found that 12 psi was my comfort limit on a stock fuel system. And that was scary enough! That was with a 20g mind you...

 

[Mr. 7M-GTE]

All right fellas, after all of your combined responses it has become abundantly clear which direction I should go in. Injectors, FP, AFPR, and THEN SAFC. I will take into account the fact that ALL of you guys have been in the Supra game much longer than I and I really appreciate the support! Well as this project starts to get off the ground I'll start build thread and keep you guys in the loop. Thanks again!

 

[winsauce]

heres my dyno sheet from 2springs ago with 50trim ct, afpr, walboro only... it can be done on stock inj if you have the fpr mod, and the pump to feed it.
its not ideal, as you can see in the 2nd graph im running rich as balls and loosing some power but as far as $ goes those 3 mods are all you need to worry about after you install proper headbolts and re tq.
I have a spare AFPR btw... why SAFC? if your interested i also have maft pro on my parts shelf.
buy those 2 mods from me and a walboro and your golden kid

 

[CajunKenny]

All right fellas, after all of your combined responses it has become abundantly clear which direction I should go in. Injectors, FP, AFPR, and THEN SAFC. I will take into account the fact that ALL of you guys have been in the Supra game much longer than I and I really appreciate the support! Well as this project starts to get off the ground I'll start build thread and keep you guys in the loop. Thanks again!

Detonation is like crack...one hit and it's all over...

We're just trying to help a brutha keep his car on the road.

 

[sweaver]

wideband o2 sensor! -> safc

 

[winsauce]

IMO... flame suit on :: angry ::
motec> aem> stinger\megasguirt> maft pro> safc> simple mbc

 

[Supra0089]

wideband o2 sensor! -> safc

+2 o2 wideband before safc

I would also recommend looking into other piggybacks than the safc...it's limited in what it can do for you...

 

[mk3tattoos]

and you need a GOOD wideband to tell you what all the mods are doing for you. you realy need to no the A/F's to be safe.




oops.....didnt see there was page 2, lol. So +3 wideband

 

[Mr. 7M-GTE]

Ok, so I've done some extensive homework and consideration on ALL of your advice/input. I'm gonna go ahead and pick up some 550's, Aeromotive AFPR, Lex AFM, AEM UEGO Wideband, and a Walbro 255. I'm gonna leave my boost alone and do a few reference pulls, then play with the fuel pressure and tuning screw in the AFM. HOPEFULLY...I can can come to a safe point where I'd feel comfortable raising the boost a few psi and re-tuning for a lil power. I...like all of you, would like to see my car continue to run!

 

[Supra0089]

Ok, so I've done some extensive homework and consideration on ALL of your advice/input. I'm gonna go ahead and pick up some 550's, Aeromotive AFPR, Lex AFM, AEM UEGO Wideband, and a Walbro 255. I'm gonna leave my boost alone and do a few reference pulls, then play with the fuel pressure and tuning screw in the AFM. HOPEFULLY...I can can come to a safe point where I'd feel comfortable raising the boost a few psi and re-tuning for a lil power. I...like all of you, would like to see my car continue to run!

sounds like you'll have an almost exact setup to what I have. I've got my fuel pressure set to 28, and the screw all the way out. Running 10-11 a/f under wot with 14-15psi of boost. I suggest start with screw all the way in and fuel pressure at 30. Back out the screw full turns and monitor your a/f. I backed my fuel off a little to 28 b/c I was burying 10 a/f under wot and running super rich. Every car is different. Goodluck.

 

[CajunKenny]

Ok, so I've done some extensive homework and consideration on ALL of your advice/input. I'm gonna go ahead and pick up some 550's, Aeromotive AFPR, Lex AFM, AEM UEGO Wideband, and a Walbro 255.

I was under the impression you already had a Lex AFM and 550's...

I'm gonna leave my boost alone and do a few reference pulls, then play with the fuel pressure and tuning screw in the AFM.

You don't want to use fuel pressure adjustments to tune with. At least not early on. Just set the FP to stock and run it that way. Once you get in the higher boost ranges, then mess with FP to see what the car likes.

HOPEFULLY...I can can come to a safe point where I'd feel comfortable raising the boost a few psi and re-tuning for a lil power. I...like all of you, would like to see my car continue to run!

You shouldn't need to re-tune with minor boost changes. You might have to make small adjustments; but, likely not. Our fuel system is a 1:1 rise. For every 1 lb of boost increased, the fuel pressure will raise by 1 lb also.