R33GTR with R32 ECU

Nistune topics related specifically to the 6303 cpu

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R33GTR
Posts: 6
Joined: Sat Aug 31, 2019 1:48 am

R33GTR with R32 ECU

Post by R33GTR » Thu Feb 04, 2021 9:08 pm

Hi guys,

I come with a few question about the tune of my R33GTR.
First a quick history :
I bought the car with a few mods :
- R34 N1 turbocharger
- 660cc denso injector
- Greddy downpipe
- HKS 3" catback
- Aftermarket air pod
- Nistune ECU
- OEM MAF but seems to have been resealed !
- OEM intercooler

The car made 440hp at 1bar and 477hp at 1.3bar.
Image
When I had a look around the car a few things were not perfect:
-Idle at 1700rpm
- The lambda wiring modification for the R33 to R32 ECU wasn't done

So for the idle I recoated the throttle body and I change all the intake manifold gasket. For the lambda I did the wiring modification.

The idle is now at 950 rpm and the lambda are working, not perfectly but it doesn't matter for the moment.

My issue is with the tune in the ECU.
As you can see in the file the Load scale haven't been modified and so the car can take around 150 of load value when all my map have a maximum of 88... So after 88 the ECU is taking the last column of my fuel and timing MAP which is the 88 Load column. This seems not a great way to tune an ECU...
The K factor have been modified but my MAF seems to be the OEM one since they are at 5 volt around 450hp. For me there ic no need to change the K factor if MAF are OEM especially with a Feature pack ECU.
The injector latency was not change either.

So my idea was to do a new tune, starting by :
-Taking OEM MAP "BNR32_RB26DETT_05U6F_MT_MECR282A_FP_maps"
- Change the injector size with smart adjustment
- Change injector latency to meet the 660cc Denso requirements
- Tune the fuel and timing map the meet the old AFR and timing level with the new tune.

I also have an issue with my car since the intake manifold job has been done :
When I open the throttle until I've got positive intake pressure and I close the throttle to change gear for example, I have a strong smeel of fuel in my car. have you ever experienced that? There is no smell when the car is running on negative intake pressure.

Thanks for your help

PS : I don't know how to attached my tune or running file, or picture in my post. Is there an explanation somewhere?

And sorry for my English, it's not my first language.
Attachments
Nistune_2021-01-29_1055_32_sural_1b_v1_boite_a_air.csv
(59.47 KiB) Downloaded 9 times
Nistune_2021-01-29_1059_13_1.2b_v1_boite_a_air.csv
(41.48 KiB) Downloaded 9 times
MAP R33 _CT.bin
(32 KiB) Downloaded 9 times

R33GTR
Posts: 6
Joined: Sat Aug 31, 2019 1:48 am

Re: R33GTR with R32 ECU

Post by R33GTR » Fri Feb 05, 2021 8:21 pm

Hi guys,

I added the pictures of the dyno test and the Map with the logs at 1bars and 1.2bars.

Cheers

Matt
Site Admin
Posts: 8683
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
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Re: R33GTR with R32 ECU

Post by Matt » Mon Feb 08, 2021 8:46 am

As you can see in the file the Load scale haven't been modified and so the car can take around 150 of load value when all my map have a maximum of 88... So after 88 the ECU is taking the last column of my fuel and timing MAP which is the 88 Load column. This seems not a great way to tune an ECU
If you are reaching TP=150 but factory load scales are TP=88 then I would suggest reducing K by 58% (so around K=130) so then the load cursor (TP) only goes upto 88

After this increase TIM by same amount 512 to 808

This should get fueling back to where you started, but reduce the total load reading... right now your AFRs are 12.5:1 before you even get onto boost. So everything is too rich

Smart adjustment will only adjust TIM (not K) if the factory MAF sensors are used

AFRs are in the 9:1 range, way too rich. May explain the fuel smell. With larger injectors you need to drop the fuel map by a similar percentage
Attachments
2021-02-08 08_15_19-Nistune [BNR32 SKYLINE (RB26DETT) Feature Pack 1.0  (Version_ 3)].png
2021-02-08 08_15_19-Nistune [BNR32 SKYLINE (RB26DETT) Feature Pack 1.0 (Version_ 3)].png (178.36 KiB) Viewed 428 times

R33GTR
Posts: 6
Joined: Sat Aug 31, 2019 1:48 am

Re: R33GTR with R32 ECU

Post by R33GTR » Fri Feb 26, 2021 9:36 pm

Hello Matt,

Thanks for your reply.
I finally found where the fuel smell was coming from. The clutch check valve was in the wrong direction, so when pressure was positive in the intake plenum, the intakes gas were coming in the clutch booster.
In the right way there is no gas smell!

I totaly agree about the fueling of this tune wich is way to rich!

Since I use the factory MAF I was thinking about starting from the OEM MAP "BNR32_RB26DETT_05U6F_MT_MECR282A_FP_maps"
- Change the injector size with smart adjustment to have the right duty cycle.
- Change the ignition and fuel load scalers to have a maximum value of 120 which correspond to 150 which was the maximum TP value recorded with the previous K (294)
- Change injector latency to meet the 660cc Denso requirements (latency 0.90ms)
- Tune the fuel and timing map to meet the old AFR and timing level with the new tune.

What do you think Matt?

An interesting graph here with the comparison of the average MAF signal with the OEM air box with HKS filter and after market air pod :
Image
We can see that the OEM Air box is less restrictive or the air flow is less readable with the air pod :P

Thanks

Matt
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Posts: 8683
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
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Re: R33GTR with R32 ECU

Post by Matt » Mon Mar 01, 2021 10:02 am

That sounds like you on the right path. Smart adjust will just change TIM from the 440CC to 660CC injectors

Adjusting TP scales should be okay if you are just adjusting the top end of the map

RomChip200
Posts: 387
Joined: Mon May 11, 2009 7:58 pm
Location: FRANCE

Re: R33GTR with R32 ECU

Post by RomChip200 » Tue Jun 08, 2021 9:29 pm

I can help you to tune it correctly (the "good practices")
_log TP (Load index = MSB) instead of TP (Load)

Few remarks:
_too rich, at idle and on boost (TP=14 @idle is wrong)
_TP scales need to be scaled correctly

Which equipment do you use to measure AFR ?

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