Some dyno questions
 

Did some dyno work today, have some questions.

1. Will dyno runs damage the speedo? We hit 186 mph on the dyno and to say the least the speedo needle was buried. So far no ill effects. Should I disconnect it next time?

2. Is the OEM boost guage accurate? I have a .8 spring on a new waste gate and it opened up big time when the guage exceeded 1.0, but before the overboost switch kicked in.

3. On a Zork tube, can you put in a wide band sensor? If I put it in the middle is it going to be double compromised by high heat on the turbine end and atmospheric gasses on the other?

BTW, on our first run this morning, the tie down straps weren't crossed, and the waste gate exhaust melted the strap almost in two. Cross straps from that point on.http://forums.pelicanparts.com/uploa...1439317397.jpg

Here are my answers:
1. I doubt the speedo is damaged but next time put the car in 3rd gear instead of 4th during dyno run.
2. The OEM boost gauge is not accurate.
3. It should be fine to put in the WB sensor in the middle of the zork tube.

Good thing the strap did not burn/break through during a dyno run!

As MikeD stated, OE boost gauge is all over the place compared to my analog unit from NHS.

What power did it make? Did you use an air fuel sniffer?

Kind of scary to dyno a car with no air fuel meter!

Shop puts a PLX sensor up the tail pipe to record AFM vs RPM. Car ran rich so only 325 rwhp. Going to put in a PLX Multiguage, boost unit, and AFM unit permanently.

Please post the dyno chart with AFRs so we can check it out. Also once you get your WBO2 meter installed if you'd like some local help dialing in your AFRs let me know.

Now for a few questions:

1. Do you still have the air pump, injection spider tubes, and other associated equipment still installed?

2. Is the stock lambda controller still installed and controlling the frequency valve?

3. What are your timing values at idle and above 4k RPM?

Personally I like the RarlyL8 CIS approach of KISS. The late 930 CIS can be simplified big time, then tuned accordingly.

What mods?

Zork + WB O2

<a href="https://www.flickr.com/photos/looneys_on_the_lawn/19444164605" title="IMG_9602.jpg by Shannon, on Flickr"><img src="https://c4.staticflickr.com/4/3687/19444164605_310b81a24a_b.jpg" width="1024" height="683" alt="IMG_9602.jpg"></a>

How long will that sensor last in that position?

Scott: no, yes, and gonna re-time car next week. Any timing specs you recommend?

Stock CDI and MFI. Leask WUR, deleted air box and diverter, Fabspeed inter cooler, B&B headers,S200 turbine, Zork: just bolt on stuff.

With a heat sink (not yet installed), indefinitely.

I want to play with a Zork or dump pipe. Is is accurate at idle (AFR readings)?

Chris Carroll seems to think so. But remember, idle AFR isn't a huge concern in tuning.

Kevin who?! I suggest getting your WBO2 installed before making any other changes... including timing.

Here is the heat sink I use:
Innovate Motor Sports On-Line Store

I agree that most likely the sensor should be fine. I don't run a zork so I don't know if the short pipe affects idle AFR. I'm guessing no.

I do feel that once everything is dialed in then idle AFR becomes a good baseline for what's happening with the engine.

Steve I'm getting ready to send you an email. Lets try and catch up sometime in the next few weeks after you get your WBO2 installed.

Kenik, who makes that zork and WG dump pipe?

I have an idea and those would get me 90% of the way there.

In my experience, yes.

Thanks

Brian Bodart (Rarlyl8) sells both the Zork and dump.

Hold up -- *sometimes* it is accurate.

Stock cams and a small mild turbo (K27) then it's pretty accurate.

If you have big breathing cams, and get some reversion, then no, it isn't 100% accurate. Even at part-throttle and low loads you can get reversion and affect the O2 reading when it's so close to the outlet.

But where else are you going to put it in a dump pipe? Not many options.

I generally hesitate putting words into other peoples mouths, and this is why. Devil is in the details. Sorry, Chris!

All good :-)

Moral of story; tune fully with straight-through muffler, then install Zork. At full boogy, she'll be accurate!