Im still curious about a couple VI questions

1) Is it ENTIRELY impossible/impractical to use 4th gen fuel rails/jets ?
2) Do the rear 3 coil packs HAVE to be 5th gen?
3) The 5th gens use a partially electronic AICV...am I correct?
4) Will the 4th gen throttle cables fit the 5th gen TB?
5) 5th gen stock injectors are ~270cc and 4th gens are what....~240 ? Won't that make you run richer? I know it wont be a significant increase to drastically cause problems....especially if youre boosted....but on N/A...??



Sorry for all the newbie questions...Im just trying to work with what Ive got in my garage.

 

1. People use the 4th gen lower IM and injectors/rails
2. If you use the 00rear vavle cover you HAVE to use the 5th gen injectors, I should have a spare set soon
3. 5th gen IACV is at the bottom of the TB, it is electrical and can be wired up from the 4th gen harness, BSWith(spell?) has done it.
4. Yes.
5. Yes, car runs richer, needs to be tuned.

 

5. I thought the ECU would adjust for the larger injectors

 

Not in WOT, in WOT it is open loop--Preset MAP.

In closed loop the ecu adjusts to the bigger injectors.

 

I'd like to know how much our ECU's can adjust even in closed loop, not just WOT. In the mid 90's LT1's for example, the closed loop control can only adjust for up to about 25% difference from stock. That means if your injector change is >25% the computer won't be able to fully compensate and will still run rich, even in closed loop.

 

I've got a question to add to this:
When I had my full DEK motor installed, it obviously came with the larger injectors than my 4th gen ones. I've noticed that the can ALMOST feels faster not going full throttle than WOT, and Kevlo's post made me think it may be because I'm running rich when going WOT. I have the JWT ECU tuned for OEM 4th gen injectors, and I was hoping it would be able to compensate for some of this, but chances are it does the compensation only when at partial throttle. Kevlo, how did you compensate for this?

 

I have a SMT6 and I have done a lil bit of AF tuning. But the SMT is not in right now. I do have the dyno from MAXUS. One is w/o SMT(no VI switchover) and the other is with SMT AF tuning, no timing. This map was not for my car so I CAN squeeze more power out of it with just AF tuning.

 

That's a fair but of power with just A/F tuning. From the looks of it, SMT units offer more in terms of power gains than JWT or TS.

 

Except revlimiter.

 

My car feels the same way, faster in partial throttle than in WOT

 

Good...your *** needs to be slowed down lol

 

Mine also feels like it has more power at partial throttle...

 

That is because it does. That is why the car needs to be tuned at WOT openloop

 

Where'd you get the SMT unit? I'm seriously considering this rather than sending the ECU to JWT.

 

Ebay.......

 

how does the SMT5 or 6 work?

 

I've noticed the same thing... WOT seems weaker. Plus, it seems worse now than when the ECU was reset. I'll probably just send mine back to JWT to get programmed for the new injectors (it's the cheapest option for me at this point as money is tight even though I'd like to have better control of it myself).

 

ha, i thought i was crazy, but it looks like im not the only one who thinks their car is faster at partial throttle than WOT. at partial, ill get put back in my seat, at WOT, it really doesnt change much. Feels slower if anything

 

 

It's all good Bijan, I might drive up there one day to eat and help you with 00vi

 

Ill give you twenny dollas

My main concerns are mainly the fuel rail/jets -- I wouldnt mind shimming down in between the manifold runners.....or the coil packs.

 

You seem lazy . Run the 4th gen lower and injectors to save time and work. You dont have to find the 5thgen injector connectors that way.

 

What about getting an Apexi AFC to control the fuel?

 

Get it and dyno tune. You can squeeze alot of power out of it.

 

So I take it that you think it will take care of my needs? What about a SMT-6/7? Same deal?

You think I can get some power out of it even with the JWT ECU? Probably....due to my larger injectors....

 

No you are not making enough power to utilize the bigger injectors. Like I have said before, all the SMT bugs are NOT worked out yet so there is no point to buy right now. JWT ECU is only good for the revlimiter IMO. The SAFC will fix your problem of running rich at WOT.

 

Ok, but what about when I spray nitrous? I'm willing to bet some power could be gained over the JWT program if I either get a slightly larger jet, or just do some good tuning with a SAFC.
Either way, at least I won't be running rich. What are some good places to get an Apexi SAFC?

 

Okay, for the first time ever, I experienced what you guys are talking about w.r.t. being faster at partial throttle than WOT. I'm the type of driver that's either barely on the gas or is trying to push it through the floor. Today, I had the accelerator depressed most of the way but not all the way and my head snapped back into my headrest. Whoa. Gotta find a dyno and get myself a piggyback unit.

 

yeah, its pretty ridiculous. so kevlo, you think that an a/f controller would fix our problems with running too rich at wot? i was talking to someone yesterday and they said they had one f/s. can control a/f every 200 rpm. Because if thats the case, I'll pick that up. The only reason i wanted an ECU was to help correct that problem, but if a A/F controller can solve it at nearly half the price, ill sacrifice the rev limiter. Or better yet, can it be used in conjunction with an upgraded TS or JWT ecu?

 

I don't see why you couldn't use a piggyback with a JWT/TS ECU. But, you'll pay out the butt for just a revlimit increase...is it really worth it considering you're an auto, Davi? I mean, when all is said and done, you're looking at close to a thousand dollars.

 

who said im staying auto? By the end of the summer, i'll be converted just like you

 

I would get the tuner just so you can tune for YOUR car. JWT tuning is not car specific, so you are not getting the most out of it. You can use the SAFC with the JWT/TS Ecu.

 

Potentially dumb question: Is the SMT unit the only unit that will allow ignition advance control?

 

nice, i will definitely look into that then. ill wait to try the dyno thing again until i get it. any recommendations on what the most cost effective one would be to get?

 

SAFCII is pretty cheap on ebay, infact I just installed a VAFCII today. Got the V one because my bud is gonna install MEVI and that will be RPM switch.


To my knowledge SMT is the only piggyback that advances timing.

 

Anyone know how many degrees JWT advances timing by? I ask because I want to know what the safe limit is for 93 octane and our engines.

 

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

ill be ordering that one next week sometime. i like that it has the knock monitor so it can tell if my knock sensor is dead or not. are these things pretty simple to use?

 

It is pretty simple to use and to instal.

THT search for a thread by I belive ENG92 or 95 in the 4th gen forums and it shows the JWT vs Stock ECU timing.

 

Thanks Kevlo; I found it: http://forums.maxima.org/showthread....nition+advance

 

So according to my future setup 3.5 full, 3.0 ecu, '00Vi, pathy TB and SAFC II will I be able to NOT run TOO rich at WOT? I don't want to run rich at WOT basically I want to run at a peak ratio, what else is required to do so? BTW I will be using '00 VI injectors, with '00 VI fuel rail and stock 3.0 ecu with stock rev limiter. I'm not doing the work tilley is lol.