Hey guys im relatively new here, just buy things from you guys here n there. I recently put in a 3.5 into my 4th gen maxima (1997), motor came off an 04 maxima. Its turbo charged with an HX35, right now at 7psi. I am used to my 3.0 and am familiar with it as far as tuning and such but im new to the 3.5 and its limits. My questions are:

I had meth/water injection on my 3.0 set to come on at about 10psi (was running 15 max), this helped me reduce/eliminate knocking, I was tuned to 10.5 a/f. Now for the 3.5, If i were to use the meth/water injection when should I start using it? i figure at 7psi I shouldnt have any pinging or knocking issues yet. also tuned at mid 10's a/f. My ecu (from 3.0) timing is at most 23 degree's, im also unsure as to how much boost i should start retarding some timing, considering my ecu advances less than Z's. Any input would be appreciated. btw, my goal as far as power wise would be no more than 9 or 10psi, just enough for 390's or very low 400's hp, anything higher would be useless on my fwd.

 

is the ECU off of the VQ30DE (4th gen stock) or the VQ35DE?

 

23 degrees advance is too much for 10psi on pump gas. For reference, a VQ35 runs ~26-27 max advance NA.

 

I am using my stock vq30de ecu.
Hal what do you recommend my timing should be at when i reach 10psi, i'll be using the meth/water injection, but I rather take back some timing than depend on the injection (in case it fails one day).

 

10.5 is really rich IMO especially with W/M, a good start is subtract 3 deg first and subtract 1 deg more for every PSI you go up. At peak TQ (4000-5000rpm) 11-13 deg @8psi is a good safe timing and you can start adding a few more deg as you get close to redline.

 

Sounds good, in what increments do you recommend i start retarding timing? in the past i have faced some hesitation because of the increments in the timing retard, the sudden change in timing i suppose is what caused the hesitation or bog. for example should I start retarding starting 1psi in maybe -2degree increments till i reach -10 degrees at say 10psi?

 

You can start retarding 2-3 deg on the first psi then start retarding 1 deg more for every psi you go up, in the end at 10 psi you will probably subtracted 12-13 deg around peak TQ. The key is you want your lowest timing around peak tq coz that is were you have a higher chance of detonating. By the way I wouldn't start boosting 10psi with the VQ35DE, with a Turbo then I say stay around 8psi for now, 8psi will give you mid-high 300whp which is right about the safe power for the VQ35DE. Anything above 400whp/TQ is pushing it a little. good luck.

 

thanx for the tips. I just made some changes, like you said, at 1psi i started taking away 3degree's, all the way to 8 - 9psi (which is the boost im getting), at 8-9psi im pulling a total of -11 degree's. car pulled hard, and was also smooth, not choppy or anything so the increments worked out perfect. Now as for a/f, what would you say is reasonable? you mentioned 10.5's is to rich, with these test runs i did with new timing i was getting mid 11's, (my maf maxed out, which i will fix asap).

 

Mid 11's are good and safe especially w/ WM. Rich best TQ is 11.5:1 so anything richer is considered very rich but, withouth meth, I would target w
11.3-11.5 and even 11.1 at peak TQ area for extra safety but that is the richest I'll go.

I'm also running meth for added protection and not for full power, with meth my AF target is around 11.5-11.7 w/ 2-3 deg more timing. Do you have anything to monitor knock? My car respond well with this # so that doesn't mean It will be the same for you.

 

what are u saing is like using an old MSD Boost Retard. u will end up with 6 -7 Degree ehehehe

this is not safe.

 

Right now I dont have anything to monitor knock, unfortunately the obd2 scanner i have does not read the knock sensor, i dont know why, it reads everything else.

I shall be hooking up my meth/water injection today and leave it in the mid 11's, although the reason is in the 11's is because my maf is maxed out, I already ordered a z32 maf, so i'll wait till then before I start enjoying the car lol. btw what mixture do you use for the injection. I normally use 50/50 water/meth

 

nah, I use an emanage to pull timing, so i can put any value I want. its not like its automatic and retards more timing based on boost if thats what you mean

 

I mix my own but I'm around 50/50 mix too, the most important thing is the consistency of the mix coz your tune is base on that mix.

 

ok good so why u wana pull that much of timing
???

for 10 PSI u should pull around 6 to 5 Degree, 93 oct

i have a map if u want it ill send it to u

i have a lot of maps for the emanage

 

It really depend on what the ECU is trying to do to judge how much timing to pull.. If the ECU is trying to run 23deg at 5500rpm@10psi then you'll end up with 18 deg timing if you subtract 5 deg only. I think 18deg is a little high for stock block and 93octane, the OP also dont have anything to monitor knock so that is another thing to consider. I'll probably run no higher than 16deg at 10psi and no higher than 13deg around Peak TQ on pump gas and stock block but that is just me.. I do run 17 deg at redline though with water/meth but Utec has active knock control just in case I do get knock..

 

man thats to low for me, well, maybe thats becouse we use a better fuel in here.

but in the end 15 -16 Degree is fair for any FI engine runing more than 9 psi.

 

Thank you for your input guys, its actually been very helpful. yesterday I did some tuning, I had previously pulled about 10 degree's across from 4k to redline, thinking that I had mid/high 20's in timing on my ecu, the car felt good only at high rpms, after every shift it lands at 4k and would just die, no power. I did what i was supposed to do to begin with, and logged my timing to see what the ecu is putting out. turns out i have this huge dip at 4k rpm, goes down to 15, then it goes back up lil by lil to 23 towards 5500 and on. So what I did, I decided for now i'll have my timing at about 13 degree's, just got the difference and inputted the proper values (for example -2 at 4k), so now i basically have a flat timing curve at 13 across the board. the car feels ALOT better, more power everywhere, and at 4k its pulling hard. im currently getting 9psi. I am still not where i want it to be 100% yet, I am waiting for a new MAF to arrive since mine is maxing right away. also my a/f is at high 10s low 11's

I am going to up the timing lil by lil as i get more comfortable with how the engine responds and such. I would greatly appreciate it if you can send me that map to check them out. u can email to me, streetzlegend@gmail.com
Thanx alot

 

Well, i no longer have a stock block. I already have 200 miles on a rebuild with 8.8:1 compression, eagle rods, acl bearings. Considering this, and the fact that I am looking for 12-17psi (or 400-500whp), Whats the most timing I should be running in this case? Id figure about 16degree's at most, saying im at 17psi for example. ?

 

Wow Streetz you have a built block now!!! You were one of the firsts to do the RMT and perfect it. I used to be on the .org and followed your progress. Congrats and I hope you get your tuning aspect worked out.

 

Thanx, we doing big things over at the org now days lol. just trying to figure out how to go about the tune now.