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K20a dyno run & bad O2 sensor?

9K views 31 replies 14 participants last post by  Bjorn 
#1 ·
K20a dyno run & bad O2 sensor?(UPDATED)

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Hi, so I went to my local dyno shop today to see what I could from my K20a JDM (Type R). Just before, I want to inform you that I runned the car with the PRC ecu for 1 year without any problem. I had a Primary O2 sensor P1166
Code but I just replaced it with a NGK Primary O2 sensor. From this point with the new sensor, I did not get any C.E.L. The car was running with 91 octane fuel. Then, when I put Kpro in the car, I upploaded the provided calibration ''for'' the K20a(the only one that was on the hondata CD). Then car seemed to run faster, however, just after the vtec engagment point (from 4000-4300 rpm) the car was ''bugging'' like the same feeling as a car that need more fuel, or ''pinging''(sorry for my bad terminalogy). Then I called the local tuner, and he told me to put 94 octane fuel in it.

So today I went to the shop and the guy started to tune the car. First bad news, he's telling me that even if I don't have a code in Kpro, the value he receive for the O2 A/F is not good due to the sensor. The value he see in KPRO is around 27:1 and should be around 14:1(what he told me). So at this point, he told but he couldnt tune the car. He told me he could use a generic wideband O2 sensor, to see the A/F but that would not be as precise as what he see in the Hondata program.
So he started to tune the car with the wideband o2 sensor.

By the way this is my setup:
Chassis: Acura Integra RS 95
-k20a Type R
-Stock internal
-RBC intake manifold with Hondata gasket
-Hytech replica header
-real mugen exhaust system for DC2 with twinloop
-Custom made short ram that goes where a RSX short ram goes..near the firewall
-Walbro 255hp fuel pump with russel fuel filter and BDL fuel rail

I ask him to tune the car really conservative because I want to keep it for real long...However, there is 2 things I noted:

1-The car does not ''ping''/''bug'' anymore at around 4000 rpm
2-There is now black smoke going out of the exhaust when vtec kick(before the KPRO and tune there was almost nothing)

By the way, I don't know why but the tuner didnt touch the vtec window(kick at 4000) or the fuel pressure(set at 58 psi)

This is my graph:

I don't know alot about tune, so I ask him why I had the two little peek at around 5000 and 6500 rpm and he told me that maybe my cold air intake is not long enough?!... and I don't understand the crazy TORQUE JUMP...From 120 to 171 TQ in like 200 rpm? Is that hurting the engine? Is that a normal curve for TQ and HP?
Thanks


UPDATE:

Hi guy! So I followed what alot of you recommended me, and went to re-tune the car at another Dyno Shop. This time I went to Synoptic Tuning (near Montreal). My appointment was on may 7 2010. I have been VERY satisfied with the service I received from the shop. First of all, before even beginning, the communication with the tuner was really good. Each question I ask him he had the answer. This put the customer in confiance and was really important for me. So my appointment was scheduled for a ''re-tune'' but the tuner quickly found out that he had to do almost a complete tune. My airfuel was going crazy before he started working on the car. So we did 1 run before to know my actual HP/TQ before starting the ''re-tune''. At this point, I was a bit ''shock'' to see the difference that both Dynapack show. My first run was 210 HP. This is 24 HP lower that what I got from the previous shop. I know that there is actually difference between temp/day/even different dynpacks. However, I did not expect a 24 WHP difference. I must tell you all, that the HP number are not important for me. I was ''re-tuning'' my engine because I know the previous tune was not optimal and want to put alot of miles on the engine with no fear.. It is only to tell you that big HP difference can happen, and trying to compare setup on forum can be confusing. Anyway, the tuner did ALOT of pulls, and worked really good and quick. He also worked in overtime(passed 5pm). I'm really happy with the service I received overall. The only thing I would have liked, it that I would have like to get a map for running on 91 octanne instead of 94, since sometime when I travel there is no 94 available. But since the tuner already passed the appointment time, I felt really not confortable asking him a 91 octane map,(he put alot of time for my dyno) plus he told me that to get a 91 map he would have to tune it with 91 octane. However, I might call back and take another appointment if possible depending on how much it would cost. Now, I can't really feel the difference in power, but the car runs SO MUCH SMOOTHER. I don't have any drop in power anymore. Vtec is set to 4800 which is very fun to drive now. Before it was pain to have vtec to 4000 with a K20a R tranny, you almost hit vtec between each stop sign even if you don't want to. The tuner also took time to explain me the Kmanager, fixed my idle and enabled me the lauch control. Here are my final graph, let me know your impression, I gained 5 peak whp from the first run. I now have 215 whp. I cannot understand how bad my setup was tuned before. The car is something else to drive now, I enjoy my Kswap much more. Communication between customer/tuner is really important, and this is what I did not received from the first shop I went.



 
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#9 ·
Hehe ok guy, before posting video of the car I want to make sure I get all my security and anti-theft system installed. I will keep you updated, I will try my new O2 from Acura this week end.

The vtec actually kick harder than my old B18C5 vtec. I know that it should be smoother. The sound is however insane, and it is very fun to drive the car, except the fact that I have to worry to find a gaz station with 94 octanne.
Is it possible to run a K20a R very safely tuned with 91 octane?
 
#26 ·
Yes finally, after all the years behind me. Thank you so much, Signal you have been my best ressource of all k20a.org since the begining.
I remember first email you were telling me ''You will see, just a K20a will be more than enought''(I was talking about doing a k24 back in the day''. I can now say that it will stay a k20a as long as the engine is running. I need to full up the A\C system soon and complete minor details on the car. I can now say that I enjoy it, 3 headers, 3 engine mounts set,2 exhaust systems, 2tunes and a bunch of money later...
 
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