Another question for you guys. What Air to fuel ratio gauges are you running?

Mine currently has a PLX AFR gauge and sometimes when the car is off it will fluctuate all over the place before settling at "LEAN'. Please correct me if I am wrong but this is not supposed to happen as this could show me some incorrect values while running.

In addition I got my BTM in and I am getting it all hooked up this week. I got the Kbob set up and wired through the firewall so but I did want to see if there are any ways to confirm the functionality of the BTM once installed, would I just hookup a timing light and confirm timing is being pulled as throttle increases or is there another way to confirm it is working?

 

I have a PLX AFR gauge and it has worked well for years.

Is the negative wire connected correctly?
Have you tried calibrating again?

 

If it is trending to lean-Nothing is wrong with it.

 

The BTM only pulls timing under boost, so just revving it won't show any timing diff.

 

Thank you, it does trend towards lean when the car is off but I have had some instances where it bounces around 14-15:5 when the car is off so I will go ahead and check the calibration and the negative cable.

 

With engine off, air with oxygen will find it's way to the sensor. It should show lean, should max out on the lean side after a while.

 

Thank you, I found that the sensor wasn't connected all the way and now it does exactly that and leans out when off.

I also got a borescope and took a look through the spark plug hole and I am just about positive that the previous owner had reused the stock rotating assembly when the motor was rebuilt.

Until I can build a forged motor which isn't in the cards for the near future (I'm throwing some money into my 4runner next) how much timing should I pull when I do step on it. As the MSD BTM allows for up to 3 degrees per lb of boost where should I set it?

The intercooled kit is set at 8PSI and I am pretty much only going to have 93 Octane in the car.

 

You can always pull the oil pan at some point to verity. It's just a PIDA too.

I haven't tested it but I was told by the the facility that sold me my Procharger kit to set the BTM at 1 degree. I was going to use 1.5 as a base and drop it from there to get the best balance.

 

Here's what you have to be concerned with: Add the high load column from the main spark table and the power enrichment spark advance table for a given rpm.

Partial Combined Spark Advance Table (from APYP) :

RPM LV8(208) + PE = Total

4800 35.16 + 1.05 = 36.21
4400 30.94 + 3.** = 33.94
4000 27.07 + 5.** = 32.07
3600 23.91 + 7.** = 30.91
3200 22.85 + 9.14 = 31.99
2800 22.85 + 7.5* = 30.4
2400 24.96 + 6.** = 30.93
2200 27.07 + 4.4* = 31.46
2000 26.02 + 2.81 = 28.83
1800 23.91 + 2.81 = 26.72
1600 23.91 + 2.81 = 26.72
1400 21.09 + 2.81 = 23.90
1200 17.93 + 2.81 = 20.74
1000 14.06 + 2.1* = 16.16
800 9.84 + 1.4* = 11.24
600 9.84 + 0.7* = 10.54
400 9.84 + 0 = 9.84

*, **: approximate interpolated values

You don't really want/need to exceed ~26 degrees advance under boost in general, but this is somewhat dependent upon the actual load and charge air temperature (which are unknown without better sensorics). Subtracting 1 degree per psi would be borderline. 1.5 degree per psi seems to be a reasonably safe suggestion.

Source tables for reference:

TABLE: Spark Advance Table

RPM LV8
32 48 64 80 96 112 128 144 160 176 192 208
4800 39.02 43.95 47.11 45.00 40.08 39.02 37.97 35.16 35.16 35.16 35.16 35.16
4400 39.02 43.95 47.11 45.00 40.08 39.02 37.97 33.05 33.05 33.05 33.05 30.94
4000 39.02 43.95 47.11 45.00 40.08 39.02 37.97 30.94 27.07 27.07 27.07 27.07
3600 39.02 43.95 47.11 45.00 40.08 39.02 37.97 30.94 26.02 23.91 23.91 23.91
3200 39.02 43.95 47.11 46.06 41.84 41.13 37.97 30.94 26.02 22.85 22.85 22.85
2800 39.02 43.95 47.81 47.11 47.11 43.95 43.95 35.86 29.88 27.07 24.96 22.85
2400 39.02 43.95 47.81 47.11 47.11 46.06 43.95 39.02 34.10 28.83 27.07 24.96
2200 39.02 43.95 47.81 47.11 47.11 46.06 43.95 41.84 35.16 28.83 28.13 27.07
2000 39.02 43.95 46.41 47.11 46.06 45.00 43.95 41.13 35.16 28.83 28.13 26.02
1800 36.56 38.67 40.08 46.06 46.06 43.95 41.13 41.13 35.86 27.07 24.96 23.91
1600 35.86 39.02 41.84 43.95 41.84 41.13 37.97 34.10 29.88 27.07 24.96 23.91
1400 29.88 39.02 41.13 41.13 39.02 39.02 37.97 35.16 31.99 24.96 22.85 21.09
1200 26.37 29.53 32.34 40.08 40.08 37.97 35.86 31.99 26.02 21.09 21.09 17.93
1000 20.04 22.50 29.88 36.91 35.86 34.10 34.10 28.13 18.98 16.52 14.06 14.06
800 20.04 20.04 24.96 29.88 29.88 28.13 27.07 21.80 16.17 9.84 9.84 9.84
600 20.04 20.04 20.04 20.04 20.04 20.04 20.04 15.12 9.84 9.84 9.84 9.84
400 20.04 20.04 20.04 20.04 20.04 20.04 20.04 15.12 9.84 9.84 9.84 9.84


TABLE: Power Enrichment Mode Spark Advance

RPM Degrees

4800 1.05
3200 9.14
2000 2.81
1200 2.81
400 0.00

 

Thank you for the table, I will save this for future use if I ever end up tuning the computer.

I installed my BTM and it made a world of difference, I haven't given it more than half throttle yet as I am still tinkering with the FMU but I have the car idling at at around 14:7 AFR and under harder acceleration it's around 10:3-11:1 and I have the boost retard set at 2 degrees per PSI and even at just half throttle this is the most fun I have had in a C4 yet, especially compared to my previous cammed 1992 6 speed.

I will upload some videos soon but thank you all for help, everything is appreciated.

 

You are still at some risk of going lean in the vicinity of half throttle, so be careful in this region. Power enrichment fueling is only active above 70.31 % throttle (2.71 volts), however you may begin to build some boost near 50% throttle, so there is a region of exposure where you may build boost without power enrichment. The fmu will help, but may not provide enough additional fuel for all situations.

tps % (load axis)/tps voltage example: https://datazap.me/u/tequilaboy/aldl...olo=2&mark=117

Since a supercharged car's manifold pressure can approach 0 psi (atmospheric pressure) around half throttle (similar to a naturally aspirated car at WOT), Power Enrichment fueling should be active even earlier (around 30-40% throttle). The fmu won't help you here. The fuel trims may help a bit, but will then likely be skewed high during PE.

 

This a good to know, yesterday I took the car up to 4k rpms at a little over half throttle and the AFR was a little rich at 10:4 area as I have the FMU running rich as I get everything touched up as a safety measure.

In regards to boost in correlation to throttle around when does boost start to get built on these centrifugal superchargers? I do know it depends on pulley size and superchargers do build boost under load but around RPMS and throttle would boost come on?

 

I start getting boost at around 2000 rpm and I have an AFR at full throttle around 10.8-11.50 which is safe for me.

 

Thank you, I gave it a little 2nd gear pull yesterday and it started to get into boost at about 2200 and I felt it increase but my boost gauge only zeroed out and didn't show any boost pressure so I need to figure that out.

In regards to the MSD BTM under harder acceleration the Tach is off by far, when driving normally the tach reads properly but when under hard acceleration it drops to about 15-1800 rpms when it is for sure north of 4000 rpms, has anyone had issues with any of the MSD systems and the tach output or is there an adapter I need to make it function properly under hard acceleration

 

Further question, what coolant temps do you guy a average, I haven’t driven the car for over 20 minutes since I got it until today and after about an hour with some slightly spirited driving temps got up to about 235ish at idle and when cruising it would average around 225 which I am not concerned with, my issue is after I shut the car off and turned off the fan, it hit 245 after a couple minutes sitting but cooled down, is this normal?

It is also a Z51 package so it does have the fan in front of the radiator as well.

 

The car also has an upgraded aluminum 3 row radiator

 

I replaced the 160F thermostat and when I'm cruising my coolant temps are around 160F and at idle the fan comes on at 192F

 

It looks like you have the intercooler in front of the radiator-that blocks a lot of airflow so I doubt you'll be able to run the AC on a hot day without overheating no matter what you do.

 

yes the intercooler is in front of the radiator, on that same note the car is still on r12 so I’m just going to remove all the AC components and throw on the TPS pulley.

I discovered that the serpentine belt was badly torn and very worn out so I replaced it and it hasn’t gone over 220 so I suspect that the water pump wasn’t getting moved sufficiently. I also picked up a 160 thermostat that’s going in soon.

 

Hey guys, what oil are you guys using?
Are you sticking with the 5W30/10W30 recommendation or are you guys using something different?