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PCV Software Programming For BOOST !!

42K views 160 replies 26 participants last post by  Dakota_1993! 
#1 ·
Perhpas I can help as I see some are having a hard time working with the software for the PCV on their Boost machine.

One question that I see a discussion on is the placement of the MAP sensor.

The charged air intake is broken down into 2 parts. 1st part is between the Turbo outlet and the throttle blade. 2nd part is between the throttle blade and the intake valve.

Place the MAP anywhere in the charged air intake you like -- But keep these facts in mind. Placing the MAP sensor at the Turbo outlet and it will read the pressure the Turbo is putting out. This is not the same pressure that is at the intake valve.

Why ?? ....... Friction loss of all the components comprising the charged air intake. Elbows/size of pipe and length/type and size of the intercooler -- -- All contribute to the loss of pressure -- Maybe as much as 2 PSI.

Place the MAP sensor between the throttle blade and the intake valve -- Now the sensor reads the true pressure/vacuum going into the cylinder -- But one then has to program for fuel delivery while in a vacuum. Not an issue if one understands this and correctly programs the software.

Personally -- I place the MAP sensor just before the throttle blade. By placing it here and data logging I can verify how much I over Boost and watch the action of the BOV. I address fueling while the charged air intake is in a vacuum in 2 tables within the software to which I'll describe later in this post.

Method of tuning for a Boosted application. I started out a few years ago with the PCV -- The PTI version hadn't been thought of then and the software wasn't quite as robust.

Being somewhat OLD and a bit brain dead (Alcohol Saturated) .. .. :rofl3: -- I couldn't comprehend fueling in a vacuum and Boost together using just one table. So -- I tuned in both TPS and Pressure. Many -- Many pitfalls tuning via this method -- But I did get pretty good tuning via this method. Even helped a few fellows out here over the years.

Then there are other terms many use. Absolute pressure - Relative pressure or atmospheric pressure -- Gauge pressure and then Kilopascal.

The software can be configured using any one of these methods or a combination of them. I can see why the user has such a difficult time with the software or if he/she thinks they have no issues -- Why their engine runs/performs poorly !!

Now -- I'll get down to programming the software that is easy for the beginner to understand.

1st is the MAP sensor. Supplied in the PTi version is a Bosch 3 BAR MAP sensor.

Three things to understand -- 1st ..... Any MAP only reads Absolute Pressure. 2nd -- The manufacturer will state the voltage and pressure operating range of their sensor. And in this case here are the values -- You don't have to understand them -- Just understand the math I'm about to show you to properly build the Voltage table. This is the table that converts the voltage sent by the MAP to a numerical value the software understands and can work with.

The operating voltage and absolute pressure range of this sensor is:

Voltage: 0.250 VDC to 4.750 VDC.
Absolute pressure: 1.59 PSI to 44.52 PSI. -- We're going to change the input to referrence pressure only - Or gauge pressure with addressing atmospheric pressure/your elevation taken into account.

It's within this table that we will change from absolute pressure to atmospheric pressure and factor in your elevation.

Here's an example of how this works -- It's really very easy to understand. At sea level the atmospheric pressure - The air pressure on your hand is 14.7 PSI (14.696 to ber exact). The sensor's low pressure value is 1.59 PSI. Here's the math -- 1.59 minus 14.7 equals a negative 13.11. (-13.11). This is what is entered for the pressure in the 1st colum. Lets say your at 1000' elevation -- Use this table to compute:



1st colum under pressure -- 1.59 minus 14.2 equals a negative 12.61 (-12.61).

2nd colum under pressure for 1000' elevation converting from absolute to atmospheric/gauge pressure:

44.52 minus 14.2 equals 30.32.

Here's a pic illustrating the voltage table converting absolute pressure to gauge pressure taking into account the atmospheric pressure at 1000'.



Only select 2 colums for this table. The software perfectly interpolates/scales to the 1000th of a volt between the low and high voltage values.

Don't understand all this -- No worries -- Just build the voltage table this exact way and providing you operate between sea level and 10,000' your Golden and will never have to come back to this table.

I don't want to loose this post so I'm letting it fly and will continue with a final posting showing how to build the Fuel pressure table taking into account both vacuum and pressure.
 
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#2 · (Edited)
Building the Fuel pressure table. I take into account 3 points. 1st is colum differential in PSI. then Vacuum and Boost -- And in considering Boost .... Taking into account the waste gate setting and over Boosting.

Here's a typical example: You're waste gate is set at 15 PSI. The charged air intake does run in a vacuum under decel and you may change your 1000' elevation that the voltage table is configured for. No worries -- Just follow this example:

Colum count: 1st 10 colums represent vacuum - 11th colum represents atmospheric pressure at 1000' and the last 18 colums represent Boost -- I allow the 3 extra colums for over Boosting. This brings your total colum count to 29. This is what you enter under Pressure Table Axis Definition/Table Size -- 29.

Populate the 1st box - Which is pressure/gauge pressure enter -10
Populate the last box with 18 -- Leaving all the intermediate boxes blank and hit interpolate. The software builds these blank pressure cells. Then hit OK and your done designing/configuring the Fuel pressure table.

2 pic's illustrating your pressure table axis:





Here is what your Fuel pressure table then looks like -- All ready for you to configure based on your desired A/F ratio value and the size of your injectors. This table is entirely hand built -- But the good thing is ...... If you run the A/T -- As you except the trims this table is rebuilt ..... SWEET !! !!



Looking at the pic -- One sees all the tuning cells ...... A bit hard to see the PSI differential between colums though. Working with the software it is easy to see - Just can't replicate with a pic. So -- I'll offer another suggestion:

A much coarser Fuel pressure tune -- Ranging from - 6 PSI to 14 PSI with a colum differential of 2 PSI -- Pic illustrating:



I hope this helps in some small way to those that might be struggling with the software.

Dynojet does offer this video to also help understand:



There is so much more to the PCV and the software like Timing/Extending the rev limiter/Nitrous/Dual fuel/Changing the fuel curve on the fly/Data logging/Launch control/Speed limiter (For youth or your favorite dealer) .. .. :rofl3:

I need another Beer -- Hope I didn't make to many mistakes ... If I did I'm sure you all will let me know .. .. :rofl3:

May The Force Be With You -- Good Luck ....... :)

:ride:
 
#3 ·
Really cool. Will have to study this a bit when im not at work. As you said tuning via tps and pressure just doesn't take all throttle position and airflow possibilities into consideration on a boosted application. Thanks for sharing.
 
#4 · (Edited)
Being somewhat OLD and a bit brain dead (Alcohol Saturated) .. .. :rofl3: --

Now I understand. ....lol. J/K. Just wanted to say thanks for your great posts and help the other day. An asset to the forum!!!

Thanks again Dave!!


Sent from my SM-N900V using RZRForums.net mobile app
 
#5 ·
1st colum under pressure -- 1.59 minus 14.2 equals a negative 12.61 (-12.61).

2nd colum under pressure for 1000' elevation converting from absolute to atmospheric/gauge pressure:

44.52 minus 14.2 equals 30.32.

Here's a pic illustrating the voltage table converting absolute pressure to gauge pressure taking into account the atmospheric pressure at 1000'.



Only select 2 colums for this table. The software perfectly interpolates/scales to the 1000th of a volt between the low and high voltage values.

Don't understand all this -- No worries -- Just build the voltage table this exact way and providing you operate between sea level and 10,000' your Golden and will never have to come back to this table.

I don't want to loose this post so I'm letting it fly and will continue with a final posting showing how to build the Fuel pressure table taking into account both vacuum and pressure.
Hey Sparky, if one was wanting to set up to operate between sea level and 10,000', wouldn't the pressure be set up with -13.11 and 34.42 (-13.11 being 1.52 - 14.7 and 34.43 being 44.52 - 10.1)?
 
#6 ·
Hey Ken --

"Hey Sparky, if one was wanting to set up to operate between sea level and 10,000', wouldn't the pressure be set up with -13.11 and 34.42 (-13.11 being 1.52 - 14.7 and 34.43 being 44.52 - 10.1)?"

Ah No -- I see your train of thought and my mentioning that altitude operating range .. Sea level to 10,000 feet.

The low and high pressure value input is for a given elevation atmospheric pressure point - Not multiple or range of elevation.

Place the MAP sensor at any given elevation point -- As an example 10,000' and the atmospheric pressure or relative pressure is 10.1 PSI. For the low pressure input the value one enters is -8.51 and for the Hi pressure point the value entered is 34.42.This then has the correct MAP sensor scaling for this specific elevation - And combined with the Fuel pressure table -- Correctly fuels the engine.

Best way I can answer this for ya -- Coarse I could be wrong ..... Wouldn't be the 1st time -- This is the way I set mine up and it works perfectly .. .. :)

Thanks fellows -- I don't frequent the Forum much anymore but with the new machine I am following the 1000 thread to see what the issues/innovations are that might be of help to me.

Good Luck !!

:ride:
 
#138 · (Edited)
Hey Sparky. I was trying to understand pressure tuning and set up but im not getting it. First-how does one know where to even start on building the voltage and pressure boxes on the pressure configuration. Ive read and read and watch videos and its just not sinking in. Ive got a 2 bar map sensor and im running a procharger. Your pictures of your pc5 stuff are all deleted. I just wish i knew what to put in the 2 voltage boxes and the 2 pressure boxes to start. And i have no idea where to start with the pressure table set up. Im in cadillac Michigan at 1310 above sealevel Can you help me. I know how to use everything else on the program i just dont get this part. I do have auto tune as well and running total 9psi of boost on pump gas
 
#7 ·
Sparky thanks for the insight on tuning with boost pressure. I have setup my maps with corrected pressure at elevation, but my map wasn't built like that it was built with relative pressure, so when I change the values it 0's everything out and im starting fresh. Can I convert the table or what is the best way to build/fill in the table. And are you tuning/adjusting values in this column?
 
#8 ·
Hey Shelby --

Sorry as I'm not understanding your compound question.

So let me make these comments relative to you specifically.

Your tuning via Relative Pressure or Gauge Pressure. This is the easiest way to tune and understand what's happening within the software. And depending how you setup the Fuel Pressure Table -- You can also tune in vacuum -- With the added benefit of -- If using the Auto Tune -- Having it correct your manually entered values in the Fuel Pressure Table.

The Voltage Table is where the Magic happens -- That being taking the input from your MAP -- Which only references Absolute Pressure and converts this to a voltage -- And converts Absolute Pressure to Relative or Gauge Pressure. This all depends on how you populate the 2 Pressure values.

Now -- You must then convert this voltage that was derived from Absolute Pressure and convert to Relative or Gauge Pressure.

Taking also into account your location -- Fayetteville, AR which has an elevation range of 800' to 2515' -- -- Then calculating your average Atmospheric Pressure and looking at the elevation/pressure table I posted in Post #1 -- The closest average elevation is 1312' with an Atmospheric Pressure of 14.0 PSI.

Now you calculate and populate your 2 Pressure entries within the Voltage Table -- And reference your method of tuning -- That being Relative Pressure.

Here's how you do this:

Select 2 tables for the Voltage Table -- It scales or interpolates correctly between the Low and High values you enter.

1st Voltage entry -- This is the low voltage reference enter: 0.250 and for the Relative Low Pressure enter: -12.41 (1.59 minus 14.0 = -12.41)

2nd voltage entry -- This is the high voltage reference enter: 4.750 and for the
Relative High Pressure enter: 30.52 (44.52 minus 14.0 = 30.52)

Hit Ok and your done with the Voltage Table. Unless you drastically change your operating elevation -- You will never have to return to this Table.

The next Table you will manually build will be the Fuel Pressure Table. Then your Target Air Fuel Table. Make sure that the Fuel Table which will display on your software screen but is disabled -- Is set to all zero's.

Hopefully this is of some HELP for you .. .. :)

Now -- Your a Master Tuner .. .. :rofl3:

:ride:
 
#10 ·
DAVE
Ive got the volts set just like you said so im on the same page so far. Next I have the target af set where I want in the auto tune but im not sure where to start building my fuel pressure table, im not sure how to start building this, I have tune right now that the isn't corrected voltage like above some im tuning via throttle percentage, but I would like to tune off boost pressure.

I understand that auto tune will correct off of the af I set but I need boundaries to run the machine at. I just installed 63lb injectors and tuned up to 18lbs of boost but im trying to get more of a grasp of how to build a new table off of boost pressure. so when I turn the boost down the fuel is corrected also.

thanks in advance
 
#131 ·
The preasure table is prety easy to set up. I had to read sparkys description a couple times to get it but all you have to do is decide how much vac and preasure you want to run. I run 15 vac +18psi. So to figure how many coloumns just add 15+18+1for 0 preasure so I need 34 columns. Go to the first column put in your vac setting -15 then scroll all the way to the last column put in highest boost 18. Then click the interpolate butyon and pcv will fill in the rest for you. When you run auto tune DONT give it a setting for idel! Low rpm (anthing below 4k on the 900) confuse it and it will just lean the crap out of it. WFO is also hard for it to tune because you dont stay in a cell long enough. It takes about 3 sec a cell to adjust.:D

Sent from my SCH-S720C using RZRForums.net mobile app
 
#11 ·
Hey Shelby --

Oh -- Ok ...... Currently your tuning via TPS with a pressure reference. This is another method of tuning -- I started out this way and works quite well but is a bit more involved to make work.

Like you've expressed -- Change to tuning via Pressure ........ Which is a much easier way to tune and understand.

Building correctly the Fuel (Pressure) Table is beyond what I can do here on my tablet --- I'll go to the shop and set that computer up and make a post on how this is done and how to properly build -- Especially referencing your larger injectors.

Check back in a couple of hours ......... Luckily I have the time at the moment -- If this were next week ....... I'd be slammed with the New Turbo'd Machine coming back Home .. .. .. :rofl3:

:ride:
 
#13 ·
Hey Shelby --

So do I -- For a sneak peek ....... Check out the avatar -- -- An early mockup pic .. .. :rofl3:

Ok .....

Your going to change your method of tuning from TPS with a Pressure reference to tuning via Pressure only -- And tuning via Gauge or Relative Pressure -- Easy.

1st -- Save your current .pvm tuning file. Give it a unique name in case you ever want to go back to this style of tuning.

Now -- Changing your style of tuning -- This is done from a clean slate.

1st is to build correctly the Voltage Table. Here is a pic for you to verify you've done this correctly. The values I've entered in building this table reflect a 3 BAR MAP and your average elevation for where you are at as I explained above.



Next is to create a template of the remaining tables. Here is how this is computed.

1st -- Establish if you want to tune in a vacuum. I suggest you do -- As then you can tune for any exhaust pop during decel and be able to set the A/F during idle. For a value I suggest 10 PSI of vacuum. This is not the correct way to represent vacuum -- But this way works for programming the software so excuse not referencing vacuum as inches of mercury.

Then -- Make note of your wastegate setting. In your case -- This is 18 PSI. Also factor in overboost. We all do this as it's the time when the throttleblades slam shut and the BOV opens -- The charged air intake overboosts. I use a 3 PSI factor.

Then -- One must set the column PSI differential. I use a factor of 1 PSI.

Here then is the math for setting the number of columns -- The template for the remaining Tables.

10 + 1 + 21 = 32 total columns.

Here is a pic illustrating how this is done ........ Set the column value to 32. Populate the 1st column with -10.00 and the last column populate with 21.00. Hit interpolate and the software populates all intermediate colums with their respective PSI value and you will see each column represents 1 PSI differential. This template holds true for both the Fuel (Pressure) Table as well as the Target A/F Table. Then hit OK -- And your done configuring the templates.



Next is to manually build the Fuel Pressure Table -- Referrencing your larger injectors.

Couple of points with this table and this method of tuning. A/T will correct your manually entered values providing your somewhat in the ballpark when you except the trims. The A/T works within an A/F range of 11 - 15:1. So you have to be in the ball park with your values in each tuning cell. Now -- How to calculate those values .......

1st -- Make sure all tuning cells have a zero in them. To set the 1st value to which has to be established before the remainding cells can be populated -- You must set this table correctly so the engine has the correct A/F you wish at idle. Here is how this is done ......

Your running larger injectors --- And your tuning in a vacuum up to and including atmospheric pressure. This represents the 1st 11 columns. HIghlight from top left to bottom right of the 1st 11 colums and enter a negative value of -- Based on the size of your injectors -- -- negative 50 (-50). This updates in your computers software only -- Now you must update the PCV -- HIt SEND MAP.



What you have effectively now done is taken the injector pulse from the engine's ECM and as it comes into the PCV -- Cut the duration of the pulse and cut it in half.

Now -- Start the engine. It will take a few seconds for the wideband to heat up and give you a display on your software screen. Once you have a A/F display -- Look at it and see if it hits your target A/F you have in your head. By the way -- disable A/T in software while you are doing this.

If your A/F is slightly lean at idle -- Then decrease the -50 value to perhaps -48. This will richen up the mixture slightly -- Then hit SEND MAP and instantly you will see a change in your displayed A/F ratio. Adjust as necessary so you hit your target A/F ratio you have in your head. At this point -- Then engine should be up to operating temp as this is important as then you should be on the normal run fuel map in the engine's ECM. There are many fuel maps within the ECM based on certain engine paramaters -- So I suggest never disabling the A/T.

Ok -- Now that you have established a numerical value for the 1st 11 columns -- Now you have to set values for each of the remaining columns. Considering the size of your injectors -- Rail pressure and comumn differential -- Take your best guess. I suggest to start use a factor of -5 differential.

This then equates for the 12th column -- This represents 1 PSI of Boost -- Take your value in the 1st 11 column and subtract -5 and enter into the 12th column. As an example in the above pic -- The 1st 11 colums have a value of -50 ........... So the 12th column enter a value of -45. And so on thru the 32nd column.

When you initially run the machine and except the trims a few times -- The Fuel Pressure Table is rebuilt. To help the A/T along -- Look at the rebuilt table and see if you were somewhat close in your -5 value between columns. If you were off you may wish to change this column differential value then start over.

Remember to enable A/T when done configuring the Fuel Pressure Table and Build your Target A/F Table entering an A/F value in each tuning cell.

Hope this in some small way HELPS .. .. .. :)

Now -- Your a Master Tuner .. .. .. :rofl3:

FUN Times .. .. :)

:ride:
 
#14 ·
This will give me a good start, I now have a better grasp, thanks to your explanation.
How long does the auto tune have to be in each cell for it to make a change in the Table/ Trim(pressure) that's where it should show up right. this weekend when I was working on tuning it, I couldn't get some of the cells to show change. especially where I needed them in the 80 to 100% throttle range at 7400rpms +.
and when I make changes in the boost pressure table like above do I need to hit send table, send map and do I need to accept the trims from auto tune everytime.
 
#15 ·
It takes several hundred engine revolutions for the A/T to populate 1 tuning cell. Several video's on the Tube of shops tuning the PCV illustrating.

When excepting the trims -- If you have the software optioned to automatically SEND MAP then no -- You don't have to hit SEND MAP when excepting the trims.

But -- As a precaution for someone new -- I always suggest to hit SEND MAP to make absolutely sure that the PCV gets the updated information.

Good Luck ..... :^)
 
#16 ·
What should target air fuel ratio be on an 800 with a low boost turbo setup? Wot and cruising? Trying hard to learn all this stuff. I'm familiar with Diesel tuning but this gas stuff is a whole different animal...lol
 
#21 ·
I assume by "low boost" you are running stock pistons then and under 8psi. I would still target 11.5 - 11.8 GAS AFR at WOT. With stock compression you are still working the engine pretty hard at 8psi and you don't want to get detonation. Cruise around 12.5 - 12.8 to be safe. Not sure how your turbo spools up. Mine still makes around 3-5psi at cruise and 5000 rpms. I would also pull .5 degree timing / lb of boost on GAS.
 
#18 ·
I did EXACTLY what Sparky suggested above and had a decent working tune in 30 minutes. I used a -3 differential, but something between -3 & -5 should be fine.

A few things that I noticed during this procedure:

1 - Watch (or have someone watch) your "auto tune ON light" on the PCV software while you drive around. You will probably notice it fall in & out of A/T at times. This is an area of your Pressure / Fuel table that will need some manual manipulation. I had my son monitor and simple put his finger on the screen and let me know. I would note the AFR and manual change those cells around his finger up or down. Like Sparky said, you have to be in the ball park or A/T turns off.

2 - Be cautious accepting A/T trims. LOOK at the Trim Table and note any big swings in numbers and manually manipulate to match the ones around it before accepting. I also recommend you zero out the A/T trim cells around idle as you have already established a good idle AFR (or zero those cells in the AFR table for time being). I do like to leave A/T on for idle once everything is done, makes for a nice steady idle when sitting still.

3 - I think many are confused with the pressure table, relative, absolute, etc. I still use my home made manual regulator and gauge and plug into my MAP sensor to validate the PCV is seeing relative boost and my voltage offsets are correct. I like this because what you see on your dash boost gauge is what the PCV sees. Makes finding problem areas much easier. Just change your voltage offsets until the PCV matches the manual gauge.



4 - Connecting your intake ports with a "balance" tube and putting your MAP sensor there will calm your pressure signals down a lot. You can even add a small pressure vessel in there as well to come it down more. The pressure signal jumps around a lot on a 900 motor when connected to only one of the IAC circuits. It can swing farther than you expect it to and chasing hesitation spots can be frustrating. This helped me get "dialed" much faster and better.

5 - Switching to E85 will simplify this whole process by 50% minimum. It is MUCH more forgiving with a broader PE (power enrichment) range from like 6.9 - 8.4 E85 AFR. This means that your tune only has to be in the ball park for the car to run OK. You will find where it makes best power, but it runs good anywhere in that range. Not to mention all the other positives.
 
#20 ·
YES!!! The concept is to abandon the TPS / Fuel table and tune solely on Pressure.

The initial -50 value that Sparky talks about is based on what injector size you are using over stock. Stock is somewhere around 30lb, so if you have increased to 60lb injectors, your initial IDLE (which is under vacuum and the turbo is not effective) fuel will need to be somewhere around -50%. So once you find out where yours likes to idle, populate EVERYTHING below 0psi with that number for an initial setting and decrease every column in the positive direction by the -3 to -5 rule.
 
#22 ·
6-8 psi non intercooled. Premium pump gas. I plan on putting in low compression pistons ( 9:1) and freshening up the top end upon install. Thank you very much for your help. Should idle A/F ratio be basically the same as cruise?

Sent from my SCH-I535 using Tapatalk 2
 
#26 ·
NO!

Stoich for 100% GAS is 14.7 and around 14.4 for 6-10% ethanol content. I idle my V8's at this ratio, but my turbo 900 motor just doesn't like that for idle. I found a smoother idle around 13.8, and talking to others this is common, especially on a boosted motor.

My GAS AFR's are roughly this:

IDLE, -10 PSI, 1250 RPM - 13.8
IDLE / CRUISE, -10-0PSI, 1250-2000 RPM - 13.0
CRUISE LOW, 0-4PSI, 2000-4000 RPM - 12.5
CRUISE HIGH, 4-8PSI, 4000-6500 RPM - 12.0
WOT, 8PSI+, 6500-8500 RPM - 11.5

Like I said, "rough"! Its kinda hard to show exactly when the table is "blended". I think Sparky has posted some actual AFR tables that look good.
 
#24 ·
Should idle A/F ratio be basically the same as cruise?

This is all up to you -- Use logic and base your A/F values on engine RPM and Load.

As an example -- On asphalt running at 50 MPH I have a Boost figure of 1.5 PSI. For this application I run an A/F ratio of 12.7

Another example -- Same speed on Sand ...... I'll run a Boost figure of appx. 5 PSI. I use an A/F target of 12.4

Think of it this way -- No matter what your operating conditions are -- You are tuning for the Boost/RPM you are operating at.

I also tend to run a bit leaner than most -- I do run 15 PSI of Boost on a 10.0:1 motor on clear 92 premixing in a bit of bean oil.

If you want to augment the timing on the pushrod motor -- Do a search as I've covered this extensively in the past. For the Prostar motor - Polaris has taken a different approach in regard to the timing -- And one can follow Brian's suggestion.

Being your running a Hot Pipe Turbo setup --- You may wish to augment your cooling system and drop your coolant operating temperature.

FUN Times .. :rofl3:

:ride:
 
#34 ·
I don't mean to derail the thread but sparkys pm's have been disabled and I wanted to make sure he see's this.

I see you suggest augmenting my cooling system. To lower operating temp im assuming...? Any suggestions for doing this? Is there a lower temp thermostat available? Drill a small hole in the thermostat?


Sent from my SCH-I535 using Tapatalk 2
 
#27 ·
Milos and I raced several times at SM over Easter. He IS FAST, but I wasn't that far behind - plus he only has 2 seats, and I have 4! His Z1 was running pretty good for the first time out. I think with a few adjustments he will pick up a bit more. Maybe a different tire, dunno?
 
#28 ·
Hey Bryan --

Thats quite a testiment for your setup as Milos has about 180cc's on ya and an additional 7 PSI of Boost !!

I really like the prospect of the Z1 -- I may go this route down the road as I now have a Speed Shop fairly close to me that does custom fab work. I still think back a year ago when I was in Queen's Shop and saw his creation with the Z1 in it -- Laying down on a bone stock N/A new motor -- Just over 532HP to the ground.

Take Care and Thanks for offering your tuning views. Refreshing to see others post on this topic !!

See Ya On The Sand .. .. :)

:ride:
 
#32 ·
Good post, thanks for sharing. We have a local shop that brings us quite a few of these to tune and I have yet to have one leave that I am 100% happy with. As was stated in this post the location of the Boost sensor plays a large part is how it runs. Preferably you would mount this on the engine side of the throttle blade but we have yet to find a good way to keep this reading stable due to the engine pulses. We have fabbed up a chamber to tap into the IAC line to see if it will buffer enough. We have never tried linking the 2 IAC lines together but will next time. Mounting the sensor on the charge tube side does not give accurate, repeatable boost readings under partial throttle. Wide open no issues but most don't run around at WOT all the time. Will post any new findings. Thanks.
 
#33 ·
As was stated in this post the location of the Boost sensor plays a large part is how it runs. Preferably you would mount this on the engine side of the throttle blade but we have yet to find a good way to keep this reading stable due to the engine pulses. We have fabbed up a chamber to tap into the IAC line to see if it will buffer enough. We have never tried linking the 2 IAC lines together but will next time.
From my experience and what I've seen, hooking the MAP sensor to the IAC circuit is a joke. With the pulse of the engine AND the IAC opening and closing (at idle) gives very inaccurate readings. At idle I would jump 6 cells on my Pressure / Fuel table - it now moves around 3 cells. Cory at Aerocharger and I discussed this in a lengthy conversation. Part of it is just the nature of the 900 engine. I drilled and taped into the bottom of my billet intake manifold and there is enough room to add an 1/8" NPT barbed fitting in each runner. My next step would be make a small buffer canister maybe out of some 1" PVC with capped ends, maybe 6-8+" long to see if it buffers it even more.
 
#40 ·
I see you suggest augmenting my cooling system. To lower operating temp im assuming...?

Yes.

Any suggestions for doing this?

Fluidyne Radiator.
Fan Override Switch/Relay.

Is there a lower temp thermostat available?

Not any more.

Drill a small hole in the thermostat?

Your on the right track. You can also cut out the plunger. The thermostat cannot be removed as it has a sealing rubber ring for the housing -- But there are a few things that can be done to it.

If one doesn't pay attention to the cooling system under Boost -- This is what can happen:



That's a pic of a head bolt out of my '902 motor. I blew 3 that day -- That one I just pulled out with my fingers with the case threads attached.

There are many precautions one can take to make these little engines live with Boost -- In my post above I've made 2 suggestions for you to consider.

FUN Times .. .. :rofl3:

:ride:
 
#66 ·
If one doesn't pay attention to the cooling system under Boost -- This is what can happen:



That's a pic of a head bolt out of my '902 motor. I blew 3 that day -- That one I just pulled out

:ride:
So what would be a safe boost level for an 800 motor? I found out, on the dyno, that adding some cooling to an intercooler can gain 7hp. Is this the cooling your talking about or more along the lines of radiator cooling? :popcorn:
 
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