RB20DET with GTR injectors

[SeriouR]

Finally have my car idling right after fixing numerous small vacuum leaks. I now have a full set of tested GTR injectors and a stock resistor pack i want to install. i need to know what latency and k constant values are people running so i can start the car and drive to tuners (about 2kms). Motor is stock besides 3 inch exhaust, front facing plenum (proper one), bosch fuel pump and VG30ET turbo. Also are there any other initial hints that could help with tuning as my tuner has only tuned power FC and link but has a good knowledge or nissan motors (tunes Robbie Wards motors).

[Matt]

Use resize injector window (untick TP load scalers)

270CC > 444CC results in K=156

Injector latency for these is about 700uS

[PL]

You might wanna consider going to Z32 AFM cos the std ones max out quite early. I have a base tune for 440cc inj + Z32 AFM. But nothing for 440cc inj + std AFM.

Basic hints? Read the Tuning Basics document for a start:

http://www.plmsdevelopments.com/files/n ... basics.pdf

But if I had to sum it up in 25 words or less:

- Adjust K constant until it sounds like it's running sweet so you can drive it.
- Check for fault codes. All fault codes must be sorted before any tuning takes place or you're wasting your time.
- Check fuel pressure. 43psi with hose pulled off the FPR and 1psi more for each psi of boost.
- Watch that it doesn't jump to knock maps. Program 5 degrees in high load areas of knock map so it'll show it instantly if it jumps to knock maps.
- Once you get to full boost adjust your load scales so you just touch the highest load column.
- Then tune your fuel map.
- Then tune your IGN map.
- tweak injector latency to get idle/low load AFR's right.

Try to avoid tuning by adjusting the VQ map like so many PFC tuners do. You shouldn't have to touch the VQ map.

OK, bit more than 25 words but I tried....

PL

[SeriouR]

Thanks for all the quick replies Matt and PL. I will try and get a z32 airflow meter then, can you send me the base map for the z32 AFM + GTR injectors? with this i take i will be able to drive the car on to a trailer to take it for a tune?

[PL]

Theoretically yes. IF you have correct fuel pressure, IF you don't have wiring errors, and IF you don't have air leaks etc. etc. I get this question all the time and the answer is always conditional on lots of things. Bottom line is that if it's been built right then it'll probably run fine with that base tune.

I did an S14 for a guy on the weekend. Fresh forged built SR, Poncams, newly fitted Z32 AFM and 740cc injectors. Smart guy though - good attention to detail. I flashed my Z32/740 base tune in, turned the key and it sat ther idling like a factory SR straight out of the showroom. And drive perfectly too. But it often doesn't go that way - there are usually lots of little things to fix up before they run properly. These things are all getting old now (like me...) and often need a bunch of repairs/maintenance before any tuning.

Drop me an email pl <at> plmsdevelopments.com and I'll send you that base tune.

PL

[sssbassil]

Theoretically yes. IF you have correct fuel pressure, IF you don't have wiring errors, and IF you don't have air leaks etc. etc. I get this question all the time and the answer is always conditional on lots of things. Bottom line is that if it's been built right then it'll probably run fine with that base tune.

I did an S14 for a guy on the weekend. Fresh forged built SR, Poncams, newly fitted Z32 AFM and 740cc injectors. Smart guy though - good attention to detail. I flashed my Z32/740 base tune in, turned the key and it sat ther idling like a factory SR straight out of the showroom. And drive perfectly too. But it often doesn't go that way - there are usually lots of little things to fix up before they run properly. These things are all getting old now (like me...) and often need a bunch of repairs/maintenance before any tuning.

Drop me an email pl <at> plmsdevelopments.com and I'll send you that base tune.

PL

man, love to get hold of that SR Z32/740 base tune

[SeriouR]

Made 191 kw on 16psi boost. Turbo is too small and cant hold the pressure at higher rpm (12psi at 7000rpm). stoked anyway NIStune works very well. this setup made approx 130kw on 11psi with standard ecu and injectors!

[Azz]

Im about to install GTR injectors into my 90 GTST. I have a walbro 255 FP also. Running a crappy GT2540 turbo. I should also upgrade to a Z32 AFM?

[Matt]

Yes you should if you are wanting over about 220rwkw. GTR injectors are low impedance. HCR32 ECU is high impedance you will need the GTR dropping resistors when fitting them

[Azz]

Thanks for the reply Matt. I have some 10watt 10ohm resistors that I will wire into the 12V feed for each injector. I emailed PL if it was possible to get a copy of the base tune for this setup he spoke about.

I assume the clone Z32 AFM on ebay like this are useless?

NEW - IMPROVED MODEL!
LIMITED OFFER - QUICK RELEASE PLUG INCLUDED
OZ Autosport Aftermarket Z32 Air Flow Meter AFM
Replaces Nissan / Jecs / Bosch item
Nissan Equivalent 22680-30P00

[Matt]

Stay away from Ebay for Z32 MAFs. I've never heard anything but problems from people who purchase from there

[Azz]

With the Z32 and 444cc GTR injectors I needed to set a K constant of 360 to get the car to idle at around 14.5:1. This is way out from the nistune values and values others have used. Factory O2 unplugged. Any idea why?

RB20DET with GT2540, Z32 AFM , 444cc GTR injectors , Walbro 255L FP