How To: Map Clamp

[AutoEuphoria]

Great writeup...made the install very easy and straight forward, and I HATE wiring.

 

[tru-boost]

Ahhh you got it done huh. How do you like it ?

 

[AutoEuphoria]

I like it a lot...seems to work great! Good AFRs, good fuel pressure...I haven't upped the boost yet over stock levels because I wanted to wait until I got the upgraded fuel pump internals and a better BPV

 

[spoolin_05]

the map clamp seems like its a little useless...why not spend the money and get the standback?? From my understanding its just a cheaper way to get a little more boost? But u still cant adjust or tune. I guess its worth it if you want to stay near stock boost lvls. But for those of us wanting to do more, we should go standback right? Im a little new so correct me if im wrong...i just got interested reading into the standback..

 

[Captain KRM P5]

for one or two psi more with bolt-ons, its not a bad way to go. some cars hit cut after just a few bolt ons honestly, and no boost increase.

 

[kingpin748]

the map clamp seems like its a little useless...why not spend the money and get the standback?? From my understanding its just a cheaper way to get a little more boost? But u still cant adjust or tune. I guess its worth it if you want to stay near stock boost lvls. But for those of us wanting to do more, we should go standback right? Im a little new so correct me if im wrong...i just got interested reading into the standback..

I run 18psi with mine and have for months. It was less than $3 to build versus $600 for a standback. You can't really compare the two.

 

[tru-boost]

There are also a ton of car with a "tuned" standback that still hit cut. The SB can tune around it sometimes but on a powerfull car it doesnt do the trick. I got the ecu flash from cpe and it seems to have stopped all my cut. The map clamp worked perfectly fine until the temps dropped, then i cut. Otherwise i could run 26psi without issue.

 

[destrux]

This is just what I was looking for. I'm used to dealing with DSM's, where you just unplug the stock boost control solenoid, pitch it toward the nearest trash can and install your MBC. Good to know there's a simple way around the speed3's boost nanny. Now I just need to pick up a boost gauge.

One question... why do some people need to tell the ECU it's only making 3.5psi and some need to tell it 15psi? Shouldn't it always be set around 15 no matter what car it's on? Won't telling it that it's only making 3.5psi (when it's actually making 16 or 17) cause the ECU to use a more aggressive timing curve, and cause knock?

 

[Mid_Life_Crisis]

One question... why do some people need to tell the ECU it's only making 3.5psi and some need to tell it 15psi? Shouldn't it always be set around 15 no matter what car it's on? Won't telling it that it's only making 3.5psi (when it's actually making 16 or 17) cause the ECU to use a more aggressive timing curve, and cause knock?

The boost "setting" should be adjusted using something like a Dashhawk. The idea is to tweak it so that you get the best a/f ratio and other values that you can. Depending on mods and the tolerance variations of the particular factory pieces you have, this can vary by a fair amount.

 

[destrux]

I see. I'm guessing that you can probably do away with the map clamp if you are using an accessport? I'm not sure if I like the idea of the car not being able to see the real map sensor reading. If it's like most cars it uses the map sensor to pick the proper fuel and timing map for the pressure conditions it's seeing. If it's seeing less pressure than the engine is actually experiencing, it probably would choose a more aggressive timing and afr value than it should. With the design of the map clamp in the OP it would affect it like this all the time, not just when overboosting. The Split Second map clamp or a boost bleeding type BCD is better, but still would cause that when you get over 15.6psi. Hmm.

If an AP would allow me to do this the correct way, I'd rather just wait till I have one of those to raise my boost.

 

[Mid_Life_Crisis]

If an AP would allow me to do this the correct way, I'd rather just wait till I have one of those to raise my boost.

Yes! He can be taught!
If you had a clamp and purchased an AP, the first thing you would do is remove the clamp.
Pretty much the whole point of the clamp is to fool the ecu into using a different map (or part of a map, whichever). This is clearly less than ideal.

 

[destrux]

Yes, yes... I'm learning. The older OBD1 cars are like tuning lawnmowers compared to these cars. I'm going for my ASE advanced engine performance specialist test in march... I've been reading books and forums to the point that I nearly have some of the books memorized cover to cover. I'm hoping to not have to retake a $70 test. Engine Management: Advanced Tuning is a good read. It seems no matter how much you read though, every ECU has it's own strategies that you need to know about. That's the hardest part. I'm hoping the idiosyncrasies of particular applications won't be on the test, and it sticks to the general stuff.