RB25DET S1 Tune for bigger turbo

Nistune topics related specifically to the 6303 cpu

Moderator: Matt

Posts: 11
Joined: Thu May 18, 2017 10:42 pm

RB25DET S1 Tune for bigger turbo

Postby akane404 » Fri Sep 01, 2017 5:14 am

How's it going guys, I am very new to tuning and I am trying to learn so bare with me here as this may seem very basic to a lot of you!

I'll get right to it. As the title states I am trying to tune for a bigger turbo, I am NOT looking for a step by step tutorial. I am just looking for the basic maps I should be looking at. So far all I have played with is the AFR primary and Gear map (They match just like stock) and a little bit of the timing map. I have a list of things here for my specific build to give you a better idea on what I am working with.

Type 2 board in Z32 ECU RB25DET Series 1 Base map
Precision turbo: GT3561e compressor .60a/r turbine .63a/r
Top mount equal length exhaust manifold
Tial 38MM WG (5.8 PSI Spring) Rerouted into exhaust
Prosport AFR Gauge Sensor mounted after WG Dump
Greddy profec II Boost controller (WG pressure currently)
Freddy intake manifold
R33 GTR intercooler (not the Nismo one)
Q45 TB
Nismo FPR (with gauge inline with fuel feed)
3" exhaust no cats just muffler
Factory 370cc injectors but I do have a full set of 740cc Deatschwerks not installed yet.

That's about all the major things, and if it matters I only run NGK BKR6E (Stock No. 6962) and still factory ignition module/coils.

My main questions:
What maps to adjust?
Can I keep Factory injectors at 6PSI?
How to properly scale injectors if I need to install the larger ones?

Sorry for the big post I just wanted to be specific as possible and please let me know if I need something else to make this turbo work, my RB25 turbo blew and no one rebuilds them near me so I need this turbo to work.

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Re: RB25DET S1 Tune for bigger turbo

Postby Matt » Fri Sep 01, 2017 6:00 pm

Start with the documentation on our website which explains about setting up tuning.

I would put your injectors in firstly (Deatschwerks are drilled out OEM injectors so not something we recommend)

1. Adjust your K constant for load
2. Adjust your TIM (total injection mutliplier) for main mixtures on cruise (14.7:1)
3. Adjust your latency for idle fueling stablisation (injection dead time)
4. Adjust your fuel table for mixtures
5. Adjust your timing table based on peak torque

Yes factory injectors 6 PSI is fine but eventually you will upgrade them

Read the software manual if you are asking how to reszie injectors (Resize injector window is covered in there)

Posts: 11
Joined: Thu May 18, 2017 10:42 pm

Re: RB25DET S1 Tune for bigger turbo

Postby akane404 » Sat Sep 02, 2017 12:52 am

I picked up these injectors as a semi-temporary fix just in case my factory injectors couldn't handle it. I am eventually going top fed with huge injectors. Do I need to up my fuel pressure at all or is 50 psi good? (based off my research that is factory)

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