How To: Map Clamp

Ok so people have done it but not posted any pics or anything - Anything you do is worthless without Pics.....so here you go.

Map Clamp - I used the following diagram and went to Radio Shack and picked up the parts and made the clamp. I couldn't find a project box small enough so I purchased a LED that had a small battery box and I gutted it out. You will need to find something yourself as well.



Once completed I took off the battery lid as well as the ECU cover and located the wires I needed according to this diagram.



The connector your want to look at is the one on the left and there are 4 rows looking at it from the angle of the Pic starting from the Top to Bottom:



The Wires/Connections you're looking for are;

Connector 2AG white/green wire is the signal - Top Row 7 Pins from left
Connector 2AU green/black wire is the 5v source - 3rd Row 4th Pin from Left
Connector 2AV brown/green wire is the ground - 4th Row 4th Pin from Left

Once the wires are located, you will want to shave a little area on them so you can solder in the connection from the Map Clamp....>DON'T cut any wires, just strip off some of the shielding.

Now on my Map clamp, I had the Red Wire as the 5v, Black for Ground and Green for Signal. Yours may be different if you purchased it online or used different colors...to each there own.

Here is mine Soldered in Place and Taped up.



Another Angle



And here is the finished product. I used some wire tubing I had laying around to run the wires through and I mounted the Map Clamp to the side of the Battery Box (where I like to put everything as you can see).



Map Clamp



Ok now how did I set my Map Clamp. Well there are 2 ways.

1. Use a DashHawk or other device that sees what the ECU sees for Boost and set it where you want it boost wise. This is how I did it as I have a DashHawk. I set the Map Clamp all the way to the left and made a run. The ECU read -8 PSI max. I then turned the clamp clockwise till I got the setting I wanted. I set the Map Clamp at 15.08PSI for now which seems to be pretty damn good. I did a few pulls and my MBC was set to 19PSI and I didn't have any issues at all.

2. Connect a long wire to the Signal and one to the Ground wires on the connections before you tape them up and then getto run them into the cabin of the car. This way you can have a buddy with you while you're making runs and they can monitor the Voltage using a Voltage Meter. Do a run, see what the voltage is and adjust as needed. I guess the common settings are between 3.5 and 4.0. However, I HAVE NO CLUE as I didn't check my voltage, just what my ECU was seeing for boost.

Shoot me a PM if you have any questions and I will help with what I can. I hope this helps others in their venture. For those of you trying new things as well, it would benefit the community as a whole if you actually took the time to document your jobs.

MBC + FCD same as MAP + MBC ?

Where does the use of a MBC and a FCD intersect, if at all, with the use of this MAP clamp and a MBC ? Do they accomplish the same end just through different paths ?..one better than the other ?

The Map Clamp replaces the BCD when using a MBC/EBC. I had the BCD before the Map Clamp. Is the Map Clamp any better? Dunno. I just didn't like the idea of bleeding of boost and liked the idea of lieing to the ECU better.

Here are some options for enclosures.

Link

Link

i mad this same exact clamp but mine only adjust up to 3.5

I'm not sure what mine clamped at as I used my DashHawk to see what PSI my ECU was seeing and clamped it at 15.06 at WOT in 4th.

If I get sometime this weekend (or if it stops raining long enough), I will see if I can get a voltage reading on it and what it's clamped at.

What you can do is adjust it till you get boost cut then back off a couple turns. To go from -8 psi to 15.06 psi I had to make about 9 turns if that gives you a starting point.

Bravnik said:

I'm not sure what mine clamped at as I used my DashHawk to see what PSI my ECU was seeing and clamped it at 15.06 at WOT in 4th.

If I get sometime this weekend (or if it stops raining long enough), I will see if I can get a voltage reading on it and what it's clamped at.

What you can do is adjust it till you get boost cut then back off a couple turns. To go from -8 psi to 15.06 psi I had to make about 9 turns if that gives you a starting point.

Click to expand...

i have mine turned to the highest it will go and that is exaclty 3.50 and i still get boost gut.. is there different resisters i could try?

samsel450r said:

i have mine turned to the highest it will go and that is exaclty 3.50 and i still get boost gut.. is there different resisters i could try?

Click to expand...

If I recall correctly, you want to reduce the voltage to make it "see" lower pressure. I'm pretty sure you need to go the other way a little.

samsel450r said:

i have mine turned to the highest it will go and that is exaclty 3.50 and i still get boost gut.. is there different resisters i could try?

Click to expand...

Turn it down some till you don't get boost cut anymore. That will fix your problem.

so do you need a BC after the clamp or can you go with out as the clamp is making the ecu up itself.

the clamp does nothing more than stop boost cut. if you want more boost, then you need a BC.

tru-boost said:

the clamp does nothing more than stop boost cut. if you want more boost, then you need a BC.

Click to expand...

This is wrong. By telling the ecu that you are never over whatever boost level you set the clamp to, the car stops trying to lower boost to its design level. The purpose of the boost controller is to prevent overboosting in cars with extensive intake and exhaust mods that are capable of producing potentially dangerous (to the motor) boost levels. Based on Laloosh's experience, you can make some exhaust mods and still have your boost levels stay within reason without resorting to an aftermarket boost controller.
Personally, I wouldn't risk it. The clamp allows higher boost, the boost controller limits how much higher.

How is Tru wrong? You basically agreed with him, stating the clamp allows higher boost (by preventing boost cut). It is not "making" you boost more, the intake and exhaust mods increase efficiency of the turbosystem, thus resulting in a few more psi. The map clamp just "allows" you to do it (within reason). By adding a boost controller, you can eliminate the boost limiting feature in 1st and 2nd gear. You can also fine tune boost and adjust based upon outside temps/conditions. It is not just for preventing overboosting. I dont believe people are "overboosting" to begin with. You can dial in a pretty hefty boost spike which tapers off when used with a map clamp.

well from what i gather is that if you use the clamp you have a preset limit on what psi the computer sees if thats true then this in effect with the stock boost controller is a limiter and controller all you're doing is setting a premeasured voltage or whatever to fake the ecu into reading a level of boost so the ecu reads lower and the clamp reads what level of boost you want. and yet again if thats true then the mbc is a precautionary measure and tuning measure only.


but i'm a rookie at turbo cars so i could be wrong.

shucky said:

How is Tru wrong? You basically agreed with him, stating the clamp allows higher boost (by preventing boost cut). It is not "making" you boost more, the intake and exhaust mods increase efficiency of the turbosystem, thus resulting in a few more psi. The map clamp just "allows" you to do it (within reason). By adding a boost controller, you can eliminate the boost limiting feature in 1st and 2nd gear. You can also fine tune boost and adjust based upon outside temps/conditions. It is not just for preventing overboosting. I dont believe people are "overboosting" to begin with. You can dial in a pretty hefty boost spike which tapers off when used with a map clamp.

Click to expand...

Did we read the same post? What I read is that a clamp will not allow higher boost. That you need a BC for that.

If you add a clamp, it effectively disables the stock boost control by making the ecu always think that the actual boost level is really lower than it is. This means that the only things controlling how much boost the system can produce are turbo size, restrictions in the intake and exhaust, and fuel availability (there may be others, but you should get the idea). The factory boost controller never "sees" full boost, so it leaves the wastegate running wide open (or is it closed) trying to increase the boost. The turbo then has nothing controlling it to a preset limit unless you install a boost control that you can set yourself.
Some people on here are seeing some pretty high spikes. Again, I wouldn't take the chance of running without some sort of functioning boost control in place.

detsilverms3 said:

well from what i gather is that if you use the clamp you have a preset limit on what psi the computer sees if thats true then this in effect with the stock boost controller is a limiter and controller all you're doing is setting a premeasured voltage or whatever to fake the ecu into reading a level of boost so the ecu reads lower and the clamp reads what level of boost you want. and yet again if thats true then the mbc is a precautionary measure and tuning measure only.

but i'm a rookie at turbo cars so i could be wrong.

Click to expand...

Maybe the wording is confusing me, but it sounds like you are of the belief that the clamp is presetting a boost target, like "okay, give me this much boost". The map is not setting a limit. It is fooling the ecu into seeing a particular result, in this case a specific boost pressure.

Oversimplified sequence of events in the management cycle.
1) You step on the gas.
2) Boost starts to increase.
3) ECU checks all the inputs, determines that you are in the correct gear and throttle opening to go "all out".
4) It reads the map sensor and determines that "hey, we can give this guy a couple more pounds" and uses the controller to set the wastegate to allow more pressure or it reads the map sensor and says "whoa there, too much boost" and the controller uses the wastegate to rein in the boost pressure.

If you have a clamp in place and set to say 10psi, the ecu thinks it is reading the map, but never sees higher than that 10 pounds, so it never gives the command to the controller to rein in the boost. It is therefore possible for a turbo to develop more boost than the engine can handle, especially without a proper tune. Now Laloosh has some significant mods to his intake and exhaust and his car holds at 19 psi with no boost controller, so maybe no matter what the test charts for our turbo indicate, in real life situations the turbo may not be capable of holding much more than this for any length of time. If this is the case, then there may be no reason whatsoever to use a boost controller, but I wouldn't take the chance.
Also, bear in mind that when we talk about boost controllers, there are two completely different levels here. There are the fancy electronic ones that you wire in to bypass the ecu and control the factory solenoid (or replace the factory solenoid and control the wastegate via the replacement solenoid) and there are very basic controllers that are little more than boost limiters. These are the kind that you splice into the air lines and do nothing more than limit max boost, as compared to the first which give you programmable boost control based on parameters you select. I am referring to using the simpler of the two to prevent a higher maximum boost than you want.
Clamp allows higher boost, BC limits how high.

Mid Life, sorry .. perhaps the wording gets confused or misinterpreted, but we are saying the same thing here. We agree, finally ... ha ha ha ... j/k

The factory boost control solenoid has to be bypassed when using a MBC or EBC, or the ECU will find ways to reduce pressure back to stock like levels. This has already been experimented with. Use loosh's write up for hooking up a boost control.

Mid_Life_Crisis said:

Maybe the wording is confusing me, but it sounds like you are of the belief that the clamp is presetting a boost target, like "okay, give me this much boost". The map is not setting a limit. It is fooling the ecu into seeing a particular result, in this case a specific boost pressure.

Oversimplified sequence of events in the management cycle.
1) You step on the gas.
2) Boost starts to increase.
3) ECU checks all the inputs, determines that you are in the correct gear and throttle opening to go "all out".
4) It reads the map sensor and determines that "hey, we can give this guy a couple more pounds" and uses the controller to set the wastegate to allow more pressure or it reads the map sensor and says "whoa there, too much boost" and the controller uses the wastegate to rein in the boost pressure.

If you have a clamp in place and set to say 10psi, the ecu thinks it is reading the map, but never sees higher than that 10 pounds, so it never gives the command to the controller to rein in the boost. It is therefore possible for a turbo to develop more boost than the engine can handle, especially without a proper tune. Now Laloosh has some significant mods to his intake and exhaust and his car holds at 19 psi with no boost controller, so maybe no matter what the test charts for our turbo indicate, in real life situations the turbo may not be capable of holding much more than this for any length of time. If this is the case, then there may be no reason whatsoever to use a boost controller, but I wouldn't take the chance.
Also, bear in mind that when we talk about boost controllers, there are two completely different levels here. There are the fancy electronic ones that you wire in to bypass the ecu and control the factory solenoid (or replace the factory solenoid and control the wastegate via the replacement solenoid) and there are very basic controllers that are little more than boost limiters. These are the kind that you splice into the air lines and do nothing more than limit max boost, as compared to the first which give you programmable boost control based on parameters you select. I am referring to using the simpler of the two to prevent a higher maximum boost than you want.
Clamp allows higher boost, BC limits how high.

Click to expand...

it was probably the wording but thanx. that gives me a total view on the clamp. also i did know the difference between the EBC and MBC. though i'm a rookie to owning a turbo car, i'm not a rookie to driving them. my lil' brother had a dsm talon with a mbc and some of my friends own turbo hondas and wrxs. but thank you the info you gave was helpful.

the cars boost controller gets its boost readings from directly from a vac. hose that connects to the turbo, not the ecu. the map clamp does nothing but help stop boost cut....thats it, period. it wont lean out the car, or change the tune in any way. if you use it on an other wise stock car nothing will change with your boost patterns....nothing ! your boost is controlled by the WGA and boost solenoid. but there is no reason to use this on a stock car. this mod works best for those with a MBC. you dial in what ever boost you want, the ecu never sees it...everyone is happy.

WTF why doesn't pics like evr load up on my computer nice write up but it just sucks i have to goto another computer to see the pics. am i missing a soft ware or something cause like 90 % of the time people post pics on here i can't see them on my computer.