Installed BIC DDP, hit fuel cut, need advice!

[Hmong_1G]

Everyone should know that fuel cut is there for a reason, and obviously a good one. Until you have a better tuning setup, I would lower the boost level of the 57trim CT. As Gaboonviper stated, the SAFC will not REMOVE FUEL CUT. Play safe and look into getting the MAFT-PRO setup. I think that the LEX-550 have its own limitations, and when that runs out you would want more.

 

[Koenigturbo]

Hijack: just curious, why did you install an "speed source Innercooler pipe? Isn't it only a 2 inch pipe? ( I read their web site) That's smaller than stock.

 

[Reiketsukan]

Get a boost controller, and put back on the cat or at least get a highflow cat.

Glad to see you got it on. Don't you have a evc? Turn it down until it is right under fuel cut until you can get the lex/550's. And doesn't Matt have a safc?

Yeah, I have an HKS EVC IV boost controller, but it's not turned on. It doesn't even have power going to it lol. The psi I have now I get from my '57 trim, DDP, test pipe, HKS exhaust.

Thanks for the info, Enraged! SUPERB product, BIC! Thank you!

It's alright, Gaboonviper85! You've made your point! I don't think their goal is to remove fuel-cut, it's to make my A/F ratio within whatever parameters necessary to make fuel cut not activate.

Hijack: just curious, why did you install an "speed source Innercooler pipe? Isn't it only a 2 inch pipe? ( I read their web site) That's smaller than stock.

I got it (used for cheap from a friend that got a 2j swap) because it increases spool and it replaced the swollen, cracking 18 year old rubber pipe that I take off to change my oil. It fits fine and it's one less piece of my IC piping that I have to worry about!

Thanks for the crazy turn-out, guys! I really appreciate the help!

 

[Turbo Habanero]

Wouldnt the BOV with the stock AFM make him run rich?

 

[gaboonviper85]

It's alright, Gaboonviper85! You've made your point! I don't think their goal is to remove fuel-cut, it's to make my A/F ratio within whatever parameters necessary to make fuel cut not activate.

a/f ratio does NOT EFFECT FUEL CUT!!!! Get that threw your head please!

Fuel cut activates because you have a bigger turbo that flows much more air at a lower psi....your AFM is what fuel cut comes from!

Read my post again and this time READ IT!

 

[Reiketsukan]

a/f ratio does NOT EFFECT FUEL CUT!!!! Get that threw your head please!

Fuel cut activates because you have a bigger turbo that flows much more air at a lower psi....your AFM is what fuel cut comes from!

Read my post again and this time READ IT!

I thank you for your info, but little less angst would be appreciated, man. I didn't understand your point due to inexperience with AFM systems. You can get your point across without being a smartass! Thank you!

Wouldnt the BOV with the stock AFM make him run rich?

Only when I let off the gas because my BOV isn't recirculated, but I can't see how that would affect my hitting fuel cut.

 

[MacDaddy_J_420]

Welcome to the wonderful world of having a upgraded ct-26 and ddp, that no one seems to really mention. I have tried numerous of things to over come this issue, but still cant get below 16psi. I tried to enlarge the waste gate hole on the turbo and recirculate the downpipe, but nothing has really helped. I finally gave up and put the car on the dyno and had it tuned then way it was, since it held up I am going to drive it the high boost level for the time being. I would say just adapt you car to take the higher boost such as lex afm/550 combo.

Here is a link to the mods I have on my car and some info on the upgrade.
http://www.supramania.com/forums/showthread.php?t=90282

 

[Supra0089]

Hello Reiketsukan. I have you're basic setup...except I have a 50 trim turbo. I hit fuel cut at 11psi, and it happens as the auto is shifting from 2nd to third on WOT.

Before the boost controller, I used to let off the throttle a tad as the auto shifted, and this would avoid fuel cut. Now I just set the BC to duty equivalent to 10 psi, and on shifting the psi spikes to 10.8psi under WOT, and wallah...no fuel cut.

I'm going LEX/550's next year, and won't worry about any of this anymore.

Hope this is helpful.
Disclaimer...I am by no means a super tech, and claim that anything I say here has a technical explanation, I just am describing my experience.

 

[Reiketsukan]

Welcome to the wonderful world of having a upgraded ct-26 and ddp

Thanks for your info! I'l probably end up going Lex/550 next summer.

Before the boost controller, I used to let off the throttle a tad as the auto shifted, and this would avoid fuel cut. Now I just set the BC to duty equivalent to 10 psi, and on shifting the psi spikes to 10.8psi under WOT, and wallah...no fuel cut.

You can lower boost with a boost controller? I didn't think you could do that...


Also, what's a j-tube?

 

[tsuper92]

Thanks for your info! I'l probably end up going Lex/550 next summer.



You can lower boost with a boost controller? I didn't think you could do that...


Also, what's a j-tube?

lex/550 is a waste of money,depending on your power goal's.change to map would be better

boost controller can only raise boost,not limit it.maybe he meant boost cut controller

j-tube is a little metal return fuel line that is bolted to the block on the driver side under the intake plenum.it is very restrictive

 

[Reiketsukan]

lex/550 is a waste of money,depending on your power goal's.change to map would be better

boost controller can only raise boost,not limit it.maybe he meant boost cut controller

j-tube is a little metal return fuel line that is bolted to the block on the driver side under the intake plenum.it is very restrictive

Then you would recommend MAF Pro? Are there freeware EMS programs like Chrome or Hondata like there are for Honda ECUs? Does bypassing the j-tube increase fuel pressure, and is this necessary when upgrading to a MK IV fuel pump or a Walboro? I ask a lot of questions lol

 

[MacDaddy_J_420]

Bypassing the j-tube is just needed to get rid of restriction when using a adjustable fuel pressure regulator and fuel pump up grade.

As far as the upgrade to rum more boost, the lex/550 combo is probably the cheapest, but doesn't have as very clean idle. There is more than one way to go to a MAP (manifold absolute pressure) set up. Ex. HKS Vein Pressure Converter (old school, but has a chip to work almost plug and play with 550cc injections), MAFT Pro (I have heard some bad things about this system on other cars, but I don't know about it for the supras), Map ECU 2 (which is what I am looking into), etc. They all do the same thing, they take a MAP signal and convert it to a frequency used to read the Karmen Vortex set up on the 7mgte ecu.

As far as EMS programs, I am pretty sure toyota has made it difficult to crack our ECU's.

Also tsuper92 mentioned a boost cut controller, this is not a very good idea unless you are monitoring everything such as afr's very closely. Toyota but fuel cut there for a reason.

 

[SupraStardom]

Your engine management totally depends on what your goals are. If you plan on running 550cc injectors and that turbo for good and never plan to step beyond that, piggy backs would be fine. If you want to go beyond that turbo and 550s then i would turn to a stand alone. AEM makes one that is plug and play and uses a MAP sensor i believe.

You should decide on the direction you want to go and aim for it. It is far more costly to baby step your way to an ultimate goal. If you want to make say 700hp then buy the standalone and you can use it now. Then orient your goals toward that. If you want to buy a new set of injectors. Dont buy 550s if you know that your gonna run 680s or 750s. Buy the injectors and put them on your shelf in the garage. Just because you buy something doesnt mean you have to use right then. You can stock pile your parts and when you have everything needed you can put it all together. Like me I have a stock 1jz in my car, but i have a 2jz block almost ready to go in the car. I have a garage full of stuff that i have been saving up for when the time comes to put it in.

Building stuff is fun but buying the same parts gets aggravating. If you drop $500 now on a piggy back then a year later drop $1300 on a standalone plus the cost of retuning your gonna be 2k into just your engine management. The game gets real expensive real fast. Be wise and do your research. It will save you lots of money. I have spent countless $$$ doing this and finally learned.

Ok enough of the soap box. Long story short. Dont buy things two or three times. Splurge a lil extra and get what you have set in your goals. And one last thing dont get a loan for parts....people finance engines and turbo kits and thats fine if you can handle it, but more often then not people end up selling there car to try to get out from underneath the payment. Plus with the job market being crap i wouldnt finance bird seed for a coo coo clock.

 

[Reiketsukan]

Bypassing the j-tube is just needed to get rid of restriction when using a adjustable fuel pressure regulator and fuel pump up grade.

As far as the upgrade to rum more boost, the lex/550 combo is probably the cheapest, but doesn't have as very clean idle. There is more than one way to go to a MAP (manifold absolute pressure) set up. Ex. HKS Vein Pressure Converter (old school, but has a chip to work almost plug and play with 550cc injections), MAFT Pro (I have heard some bad things about this system on other cars, but I don't know about it for the supras), Map ECU 2 (which is what I am looking into), etc. They all do the same thing, they take a MAP signal and convert it to a frequency used to read the Karmen Vortex set up on the 7mgte ecu.

As far as EMS programs, I am pretty sure toyota has made it difficult to crack our ECU's.

Also tsuper92 mentioned a boost cut controller, this is not a very good idea unless you are monitoring everything such as afr's very closely. Toyota but fuel cut there for a reason.

I'll never use anything like a Fuel Cut Defender or anything like that. That negates a safety precaution put on there for good reason! Ideally, I'd like a set-up that idles and accelerates as smooth and stock and is just as safe a/f ratio wise. Has anyone else had any experience reguarding Map ECU 2 or the HKS Vein Pressure Converter?

I'm going to try adjusting the screw on my AFM first (a little at a time), then if that doesn't work, I'm going to throw my stock cat back on.
When I started this project, I never thought I'd have to upgrade other stuff and make even more power to make it work correctly... If nothing else, it's a great excuse to make my car even faster!

 

[Reiketsukan]

I wouldn't finance bird seed for a coo coo clock.

No doubt!! I'm fairly responsible when it comes to my financials... I don't want to go beyond what I can make with this turbo until well after I finish college, so I'll plan for that. I'm honestly not that power-hungry, so I'd sacrifice speed for reliability and longevity any day. I'll keep doing research and do my best to figure out what will work best for my application!

 

[Supra0089]

This may be a silly question, but, do you have any boost leaks?

My bro's MK4 was hitting fuel cut b/c one of his IC piping wasn't strapped on tight enough etc etc...

 

[NewGen]

This may be a silly question, but, do you have any boost leaks?

My bro's MK4 was hitting fuel cut b/c one of his IC piping wasn't strapped on tight enough etc etc...

Remind me on friday chase and will boost leak test your car while were taking the boost controller off since those seem like the 2 easiest things to try.

 

[Reiketsukan]

Remind me on friday chase and will boost leak test your car while were taking the boost controller off since those seem like the 2 easiest things to try.

Right on, Matt!!

 

[Hmong_1G]

Many Karmen setup uses a honeycombo inside before the sensor. This helps slow and direct the air charge, which will give a better reading for the AFM. This is very common on DSM, 3SI, Nissan,Older GM MAFT, ECT.

I was wondering if this minor factory innovative would help with the toyota AFM? It's a good try as you can find these honey comb at the junk yard easily. (when this honey comb is removed you get unstable readings and most of the time richness)

Might be able to solve many things. Someone with more knowledge should shine in to why toyota didn't use the honeycomb method.

 

[supradjza80]

well I will tell you, since you are running just wastegate boost, and not using your controller that the proper fix is to enlarge the wastegate hole on the turbo so that the wastegate can evacuate more air around the turbo.

I run the DDP as well and my car fuel cut in every gear but first. Took the turbo off and enlarged the wastegate hole from 23mm to 29-30mm (max for the stock flapper) and the car still fuel cuts at WOT in 5th gear at around 13 psi with the stock turbo (this is on wastegate boost, AVC-R turned off). The DDP's just make the wastegate way to small to properly regulate boost. I would like to get a bigger flapper and make the waste gate 40mm so it can easily control boost correctly. But it will be a while before I do this.

The thing that is wierd about it in 1st-3rd gear my ported wastegate is fine and can keep my preset boost level without issue, but in 4th and 5th above 4k rpms it just slowly creeps with RPM's and finally FC's in 5th. This is due to the higher engine loading but kinda odd still.