Thread: Tuning Saga: A Love Story About a Man and His Daughterboard

billc, so the Cat converter O2 sensor is actually useful? I know that pre 98 200sx/99 Sentra's use the narrow O2 sensors. Afterwards they started using the bigger ones with a longer cat too...

Mine right now is kinda damage and I didn't want to bother with replacing it because I was under the impression that all it does is make sure the Cat is working...

no...its not. its just there to make sure the cat is working

you missunderstood what he was saying.

hes saying the stock o2 sensor is a narrow band sensor (as apposed to a wide band). Not that the "narrow o2 sensor" ... the one you are thinking of

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Oh oops, my mistake . It was late last night and I wasn't thinking straight hehe

OK, here is a quick update. Fixed the oil leak in the J30, then it blew a head gasket. I salvaged the car and never looked back.

Then I got hung up on getting my VE past MD emissions testing. She passed on the ninth try. Now I know how to do it -- add an AIV system.

Finally, I'm back to the Tuning Saga. Refresher: AEM CAI, HKS 60mm exhaust, 2 pulley set, and Topspeed Header. I am modifying Calum's SR20DE v.4 tune.

I swapped the Topspeed header out for an SSAC with 2.5" collector to see whether the shape of the power curve would change. I made it to the dyno today. Here are the results:

1. Run 013, the red line, is the best run that I made with the Topspeed in January 2008. At that time, there was no power found by changing timing.
2. Run 036, the blue line, is the first run that I made today with the SSAC. It looks like a different engine! Lost lots of mid-range and gained it back up top at high RPM.
3. Run 037, the black line, is the SSAC with 2* more timing advance. Just this small change in timing gained back half the lost mid-range, added 4WHP to peak power, and leaned the mixture out to 12.7-12.9. Right where I like it.
   

More timing advance did not add power, so I just went into the timing map and added 2* in the last 3 columns above 3000 RPM.

Now I'm wondering about whether the AEM CAI (2.5") is a limiting factor. I'm going to add S3 cams and go to a 2.5" exhaust.

Which header should I use -- Topspeed, SSAC or HS Gen 3?

Should I start with the current tune or go back to the OEM tune when I install the cams?

Will update as I proceed. As always, your thoughts are appreciated.

Bill

Anyone know how to size a dyno scan down to a normal page width?

Wow so it looks like you gained more power with the timing then with the header...

I don't think the 2.5" intake will be much of a limiter on stock cans at 120whp. Get yourself a flow stack (BPi is probably the cheapest/best) if you want around 5whp.

How did your torque change between the timing and headers?

I would personally stick to the SSAC, it seems to be doing a much better.

Here is the dyno temporarily posted on my photobucket.

Yep -- I've got a Flow Stack that I will be testing.

Adding timing advance did not produce more power with the Topspeed header, only with the SSAC. So it was the combination of timing and header. I still feel like the Topspeed does a great job for mid range where a street-driven engine spends most of it's life.

Now with a BPi Flow stack, if you have good before/after dyno results you can get another flow stack for free minus shipping. I think he might even just reimburse you for that one.

Now I'm going to dyno test this too, but it seems like the further the flowstack from the MAF, the less positive results will show up.

On a real dyno, draw through setup on a T25, having a flowstack vs no flow stack did 2whp, then 3 more whp with the filter on.

On butt dyno, blow through setup on a T25, driving with a flowstack and without didn't feel any different. But it does help with the turbo spooling.

Even draw through, at the dyno I noticed that with a flow stack my turbo and RPM's went up quicker with a flow stack.


I see what you mean about the top speed header, it does have a very interesting power band. Now timing probably didn't help with it because it was becoming a flow restriction. Increasing timing means more complete burn, thus more exhaust gasses. The power that was gained via timing was lost via back pressure. I wouldn't be surprised if timing made you loose power

P.S take the picture that I put up and upload it, it wont be there for long

Thanks for the "right-sized" image.