How reliable is the ZR1 MAP at reading boost?

[Kakashi]

I finally installed the ZR1 MAP sensor on a 2010 LS3 with a procharger p1sc-1 tuner kit (stage 1 up to my knowledge) and re-tuned the car. As far as power mods go, it is stock except for the procharger kit (ie. no intake manifold, no ported TB, no headers, no catback, no cutouts) and made 497rwhp/452rwtq at the dyno @ a reported ~5psi (ok, ok, it was more like 5.31 or something close to it) @ 6.5k rpm. the boost reported was increasing linearly from what I can remember seeing in the computer screen (give or take ~1.25psi @ 2k rpm, ~2.X psi @ 3k rpm, ~3.Xpsi @ 4k rpm, ~4.X psi @ 5k rpm, ~5.X psi @ 6k rpm from what I could oversee in the graphs at the dyno shop).

The reason I ask is because I have no idea what the pulley sent in the "kit" should be. I keep reading it is 5psi in some places, and 7 psi in others. And since I received the wrong kit from what I ordered (ordered the "complete" kit which is supposed to come with 7psi, but got sent a "tuner" kit by the vendor - long story, don't ask :( ), I have no way of knowing. Is there any chart that reports SC pulley size vs crank pulley size vs psi (on our stock cars)?

Basically I want to know at what boost I should really be at (pulley-wise) to see if I am where I should be in power or if I should start checking for leaks.

[Unreal]

Boost depends on other things too, cam, intake, exhaust, elevation, etc. The sensor is accurate, but there is no such thing as a "5psi" pulley or "7psi" pulley. The pulley I have some see 22psi but I see 10. Elevation, heads, cam, crank pulley size, etc all play a huge role.

[bumblebeecamaro]

I have a ZR1 sensor in my Maggie car and the boost levels on the ECM pretty much match the boost readings on my boost gauge.

[1stGM]

A 4.63 pulley will make 6psi with a P1 and no other mods..

[Redline Motorsports]

As long as you have the correct MAP scaler and MAP offset values the sensor is dead on...nobody knows that sensor better then Bosch and GM gets the data from them. It should be;

MAP Scaler 312.5000

MAP offset -11.25

Howard

[acowherd]

Originally Posted by Redline Motorsports

As long as you have the correct MAP scaler and MAP offset values the sensor is dead on...nobody knows that sensor better then Bosch and GM gets the data from them. It should be;

MAP Scaler 312.5000

MAP offset -11.25

Howard

Is that all that needs to be changed in order to run zr1 map? Won't throw any thing else off in the tune?

[stanwilliams]

Running boost over a few psi with the stock MAP sensor will cause you AFR to go lean do to the fact that the Inj rail press delta is reported wrong. Putting the ZR1 map sensor in with the correct scaler and offsets will make everything work as its supposed to. If your custome tune corrected for this error by fudging the MAF table or PE table then you could be a little rich when you change out the sensor. Your tuner should be able to correct this when he changes your map settings. My stock Whipple tune did nothing to compensate for this error and went about 5% lean before I changed to the ZR1 map sensor.

[JDP Motorsports]

Originally Posted by Kakashi

I finally installed the ZR1 MAP sensor on a 2010 LS3 with a procharger p1sc-1 tuner kit (stage 1 up to my knowledge) and re-tuned the car. As far as power mods go, it is stock except for the procharger kit (ie. no intake manifold, no ported TB, no headers, no catback, no cutouts) and made 497rwhp/452rwtq at the dyno @ a reported ~5psi (ok, ok, it was more like 5.31 or something close to it) @ 6.5k rpm. the boost reported was increasing linearly from what I can remember seeing in the computer screen (give or take ~1.25psi @ 2k rpm, ~2.X psi @ 3k rpm, ~3.Xpsi @ 4k rpm, ~4.X psi @ 5k rpm, ~5.X psi @ 6k rpm from what I could oversee in the graphs at the dyno shop).

The reason I ask is because I have no idea what the pulley sent in the "kit" should be. I keep reading it is 5psi in some places, and 7 psi in others. And since I received the wrong kit from what I ordered (ordered the "complete" kit which is supposed to come with 7psi, but got sent a "tuner" kit by the vendor - long story, don't ask :( ), I have no way of knowing. Is there any chart that reports SC pulley size vs crank pulley size vs psi (on our stock cars)?

Basically I want to know at what boost I should really be at (pulley-wise) to see if I am where I should be in power or if I should start checking for leaks.

There are a lot of factors that play into this question and not a ton of information. With your modifications and the base ProCharger kit you should be around 6-7 psi but without knowing your current pulley size I couldn't tell you for sure. I'm assuming you're close to sea level so you should be in the 6-7 psi range. You might want to check for belt slip.

Originally Posted by acowherd

Is that all that needs to be changed in order to run zr1 map? Won't throw any thing else off in the tune?

That is correct; those are the only changes needed.

MAP Sensor Linear 312.50 kPa
MAP Sensor Offset -11.25 kPa

Kind regards,

Jordan Priestley
888.308.6007

[acowherd]

Originally Posted by JDP Motorsports

There are a lot of factors that play into this question and not a ton of information. With your modifications and the base ProCharger kit you should be around 6-7 psi but without knowing your current pulley size I couldn't tell you for sure. I'm assuming you're close to sea level so you should be in the 6-7 psi range. You might want to check for belt slip.



That is correct; those are the only changes needed.

MAP Sensor Linear 312.50 kPa
MAP Sensor Offset -11.25 kPa

Kind regards,

Jordan Priestley
888.308.6007

Once you make those changes..how do you go about setting up your HP tunes scanner to log boost?

Thanks

[Unreal]

Just log your map sensor, probably reading in KPA. Then convert it.

[Kakashi]

First of all, thank you all for the information provided

---

I have no way to log it :( I did not tune it, it was a professional custom dyno tune. The tuner was as surprised as me of such low boost reading, but if the sensor is accurate (he did tune the ZR1 MAP sensor in with the offset and all) the most it read was 5.31 of boost. And yes, this is at sea level, although the humidity here sucks.

Now, don't get me wrong, I'm happy at the results! That is almost 500rwhp with only 5 of boost I just wanted to see if there was more left on the table (ie. if the pulley size that was sent on the tuner kit is supposed to provide more "boost" on a completely stock car, then I would start checking for belt slipping or leaks, but if it's right at the mark where it should be, then I would go celebrating )

I took some quick measurements of diameters an the supercharger pulley was in between 4 3/4 inches & 5 inches (I would say it was 4.87" or very close to it), and the measurements at the crank pulley were in between 7 3/4 inches & 8inches (I would say it was ~7.87" give or take)

I'm just a curious person Wanted to see if there was a chart for our cars stock (as I understand modifications such as headers, cams, lifts and other variables can lower the boost readings, even if the power stays the same or increases) somewhere along the lines that said:
-If Crank Pulley 7 inches & Supercharger Pully 5 inches, you should see about 5 boost on a stock car
-If Crank Pulley 7 inches & Supercharger Pully 4 inches, you should see about 7 boost on a stock car
-If Crank Pulley 8 inches & Supercharger Pully 5 inches, you should see about 7 boost on a stock car
p.s. these last numbers were randomly made up, just to illustrate what I was trying to find.

[nitto85]

Appreciate the info Redline Motorsports.

Other than needing the tune adjusted, is the ZR1 Map sensor plug and play with the current plug that is on the SS Camaros? Or do I need to buy a different cable to plug into the ZR1 MAP Sensor?

[JDP Motorsports]

Originally Posted by mst504

Other than needing the tune adjusted, is the ZR1 Map sensor plug and play with the current plug that is on the SS Camaros? Or do I need to buy a different cable to plug into the ZR1 MAP Sensor?

That is correct; it is a plug and play set up.

Kind regards,

Jordan Priestley
888.308.6007

[Kakashi]

Originally Posted by JDP Motorsports

There are a lot of factors that play into this question and not a ton of information. With your modifications and the base ProCharger kit you should be around 6-7 psi but without knowing your current pulley size I couldn't tell you for sure. I'm assuming you're close to sea level so you should be in the 6-7 psi range. You might want to check for belt slip.

S/C Pulley has 4.50 imprinted on it (measures about 4.87 in diameter from the outer lips)
Crank pulley (meassures 7.87 in diameter from outter lip to lip, i see no numbers imprinted on it but it was dark)
Belt is a DB660I-008
Sea Level

Would this help?