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14.5 is pretty damn lean considering those things run low 12's bone stock.
I would be doing a bunch of checking before I beat on it again.
Did he happen to log it when he pulled it?
I would also asked him the last time he calibrated his WB02 and if it's working properly.
I'm kinda suspect how it held 14.5 the ENTIRE run and didn't swing one way or the other.
When WB02's go out, they always show lean because of the design of the pump cell in the sensor.
I'm actually surprised he finished the pull. If I would have pulled it and saw 14.5 on the WB I would have stopped. If the WB was reading accurate I would have declined to make anymore pulls.
It's not worth the risk blowing someones car up because you know the guy pulling the car is going to get blamed somehow.
Just my .02
Amen. I second all of this. How did the WB stick to 14.5? Even a perfectly tuned car has fluctuations. Air is always changing. Impossible to hold at 14.5 or any AFR.
Amen. I second all of this. How did the WB stick to 14.5? Even a perfectly tuned car has fluctuations. Air is always changing. Impossible to hold at 14.5 or any AFR.
Normally when they fail completely they go dead lean, most of the time they show 18:1 or 22:1 or thereabouts, depending on the AFR gauge.
Every time I've had a sensor fail on the dyno that's what they have done due to the pump cell dying or being contaminated. I'm not sure if the sensor is starting to go south if would start reading on the lean side.
I'm "guessing" that the WB02 was in the tail pipe which can cause some goofy readings depending on the how the tail pipe is made but usual doesn't cause any problems at WOT, just at cruise where fresh air gets sucked in the tail pipe due to reversion. But the consistent 14.5 thing is still strange unless it is the sensor.
Seeing a log would help figure out if the WB02 was telling the truth, the narrow bands should be dead lean if it was really 14.5
I would also think the car would pretty much lay over it was that lean.
Before the dyno RPM Performance has the car owner sign a waiver for any engine that wasn't built by their shop.
I didn't get the "vibe" that they were careless with car in the least. I set the rpm limit at 5,800 rpm and the first pull as a test run was a little under about 5,400 rpm.
I don't recall seeing an O2 sensor in the tail pipe. Not sure exactly how they determined 14.5 AF, I did ask the operator insisted the AF was OK.
Lil'Jay, Thank you for the info that a Dynomite is often ~16% less than a typical DynoJet. Under the circumstances I would be very happy with~275 to 280 whp baseline for this Z28. Hopefully, when the weather clears I can visit Norris Motorsports for a baseline on a DynoJet that I'm familiar with and know Mike's AF readings will be accurate.
...
I don't recall seeing an O2 sensor in the tail pipe. Not sure exactly how they determined 14.5 AF, I did ask the operator insisted the AF was OK.
...
Time to hit up the other Dyno shop, for sure. Unless they have a wideband plugged/bunged in to your exhaust (which I doubt, unless you already had a spare bung installed from before) they would have no way of knowing your AFR without a tail-pipe Wideband. The fact he insisted the AFR is ok is troubling - because without a wideband, what did he use to determine AFR then? "Maths" ?
I'm curious to see what the other dyno shop results will be! :-)
Yes, looks like a new baseline at Norris Motorsports is in order for the spring. Will have to talk with Mike and plan a few basic mods like headers etc.
Update - Its taken an extra year but the 02 Z28 is now at Norris Motorsports for a Dyno Jet baseline. Hope to have the baseline in the coming week and possibly pick up the car at end of week.
Mile wanted to baseline the car before doing intake & headers to see if the car is a turd before going forward with install.
On Norris's DJ a stock LS1 A4 2.73 gear fbody typically makes between 260 whp and 285 whp according to the shop. Norris's DJ has new DJ updates etc.
Stock 02 Z28 w/249,xxx miles
Mod list
Green air filter
98mm FTP Lid
85mm Z06 MAF
92mm Warr TB
90mm snout LS6 intake
TR55 plugs with MSD wires
1 7/8 headers from Speed Engineering
Kook's Y pipe
SLP Dual/Dual with cut out
plus tuning
Last edited by 99 Black Bird T/A; 04-12-2020 at 08:12 PM.
The car is Norris Motorsports waiting for a slot for its dyno tuning. Big shout out to Mike & the crew for over coming several problems with the project. This shop is A++ in my experience. Great communication & quality work.
Mike Norris finished tuning my 02 Z28 and I'm very happy with the results.
The cheap-o no name rock hard tires are still on the Z28 and spun on the dyno so the middle range of dyno isn't accurate. I held off on doing the rims & buying new tires first in case the cars 250k mile 4L60e didn't survive the dyno tuning. Due spinning tires the torque curve shows a straight line mist of the time. Unfortunately, we can?see the middle range gains just the upper rpm gains.
Baseline peak 280whp
Intake & headers peak 326whp
46whp gain peak vs peak 50whp gain on the top end after peak power!
Green is baseline, After install Red is before tuning, Blue is tuned.
We'd planned to have a cut out vs SLP Dual/Dual graph too but at this power level the difference was negligible as in like 2whp and hard to see. Blue is open cut out.
I felt it was more worthwhile to show what can be gained with a good tune. Mike Norris absolutely nailed the tune on my 02 Z28. The WARR TB drives and idles very nearly stock. I'm confident it drives as well as a NW TB would have - at less than half the price!
Thefitment of the Speed Engineering headers was very bad on my car. My car had motor mounts done several years ago my prior owner. I'm sure glad the mounts aren't new because the header collector is against the floor board. Mike had to pry the headers down to get enough space to slide the Y pipe into place. My old Kooks Y pipe fit perfectly wit the headers but it too is pressed to the floorboard under the driver seat. One can feel exhaust vibration in the drivers seat but it's so tight it doesn't rattle at least. I'm 99 perect sure the SE headers would have had a shitty fit with the SE Y pipe too since the collector angle is slightly vs the floorboard. I paid $175 for the SE headers vs $1,100 for a set of Kooks. The SE definitely made good power. I can live with the SE's until its new motor time. The header install took four hours.
Last edited by 99 Black Bird T/A; 04-20-2020 at 10:14 PM.
My pet 90mm LS6 intake required a little tweaking to get properly set up. I'm posting this info not as any sort of dig or gripe. I'm happy with the intake and install. I've talked a lot of the forum about the virtues of the LPE/TPIS 90mm LS6 and done a lot of flow bench testing with the intake. I have two of them I just wanted share the following info in the interest of full disclosure. The other 90mm LS6 on my 91 RS was plug and play no issues at all.
The throttle cable bracket was slightly off on this intake. I spoke with Lingenfelter today about this issue. LPE said if there were issues send it back and it would be taken care of. In the end the 90mm LS6 seems to be working fine after Mike trimmed the throttle cable bracket. LPE definitely proved again they are a fantastic shop A++.
This is one of the reasons I really like LPE and keep using them as a key vendor for my projects
The cable issue.
TB bracket trimmed and installed. Works fine.
Big thank you to Norris Motorsports and Lingenfelter Performance Engineering. Kudos!
Mike Norris finished tuning my 02 Z28 and I'm very happy with the results.
The cheap-o no name rock hard tires are still on the Z28 and spun on the dyno so the middle range of dyno isn't accurate. I held off on doing the rims & buying new tires first in case the cars 250k mile 4L60e didn't survive the dyno tuning. Due spinning tires the torque curve shows a straight line mist of the time. Unfortunately, we can?see the middle range gains just the upper rpm gains.
Baseline peak 280whp
Intake & headers peak 326whp
46whp gain peak vs peak 50whp gain on the top end after peak power!
Green is baseline, After install Red is before tuning, Blue is tuned.
We'd planned to have a cut out vs SLP Dual/Dual graph too but at this power level the difference was negligible as in like 2whp and hard to see. Blue is open cut out.
I felt it was more worthwhile to show what can be gained with a good tune. Mike Norris absolutely nailed the tune on my 02 Z28. The WARR TB drives and idles very nearly stock. I'm confident it drives as well as a NW TB would have - at less than half the price!
Thefitment of the Speed Engineering headers was very bad on my car. My car had motor mounts done several years ago my prior owner. I'm sure glad the mounts aren't new because the header collector is against the floor board. Mike had to pry the headers down to get enough space to slide the Y pipe into place. My old Kooks Y pipe fit perfectly wit the headers but it too is pressed to the floorboard under the driver seat. One can feel exhaust vibration in the drivers seat but it's so tight it doesn't rattle at least. I'm 99 perect sure the SE headers would have had a shitty fit with the SE Y pipe too since the collector angle is slightly vs the floorboard. I paid $175 for the SE headers vs $1,100 for a set of Kooks. The SE definitely made good power. I can live with the SE's until its new motor time. The header install took four hours.
In my car I had to put prothane mounts. The se headers were a little close with the tired out stock mounts and they were touching the k member. With the new mounts there is good space between the headers and the floor and k member. I recommend the prothane mounts.
The 90mm intake is damn good. Mine is ported too by edgyvette, runners and mounth. If I could ported more I would do it but I think is maxed out.
Thank you, I appreciate the tip on the Prothane mounts. I've read doing where folks say doing motor mounts is one of those jobs that's so frustrating new get invented! Wish I had thought about doing the heat shield under the intake. That seems like a good idea! Will add those to the list.
Speaking of max porting etc, the LS6 runners will max out around 275 cfm of air. That's the max I've seen on a flow bench with a well ported 90mm LS6. In theory, a 90mm LS6 might be able to do about 600 flywheel hp NA or about 520 whp. Props to TPIS for developing the trick snout mod.
Last edited by 99 Black Bird T/A; 04-22-2020 at 03:45 PM.
01-15-2019, 05:52 PM
I just wanted share the following info in the interest of full disclosure. The other 90mm LS6 on my 91 RS was plug and play no issues at all.
