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Discussion Starter #1
ive been enjoying my jrsc+bbk until i hooked up a boost gauge and saw the im only hitting 7psi. i thought it was supposed to be something like 10 or 11 psi. whats the deal? anyone else have this problem?
 

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what other mods do you have?

what is your rev limiter set at?

Better cylinder head, headers, etc, all make the motor more efficient, therefore you lose boost, but gain power.
 

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Discussion Starter #3
all i have is headers,flex,exhaust. rev limit is stock and so is everything else. what does your vac read? mine says 20 or a little less when im cruising. i wonder if there might be a little leak where the hose connects to the guage. could this be possible? but i cant hear anything so i dont know.and also wouldnt i lose some vac?
 

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Since you have header, flex, and exhaust--you made it so there is less backpressure so your boost reads lower. Even though the gauge shows less boost your car gained more power because it is more efficient like VenomRogue said.

BTW: I think ZX3's put out 9lbs of boost with the JRSC+BBK
 

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That, and your stock rev limiter thats at, 6750 or something? You get more boost as the revs go up, I rev mine to 7100 and see about 9 lbs of boost, keeping in mind that I have a FR head..which i lost 2-3lbs of boost with.

The exhaust probably lost ya about 1.5 lbs of boost, and I think you would see the rest of the boost your expecting if you raised your rev limiter to around 7000 or so. Keep in mind though, that if you havent reloacated your IAT, then this will push even more hotter air into your motor, so make sure you get your tune right.
 

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kharazmatik said:
all i have is headers,flex,exhaust. rev limit is stock and so is everything else. what does your vac read? mine says 20 or a little less when im cruising. i wonder if there might be a little leak where the hose connects to the guage. could this be possible? but i cant hear anything so i dont know.and also wouldnt i lose some vac?
My vac reads about 10-15 when im cruising. You could have a leak in the engine bay somewhere and venom said, you exhaust and stock rev limited are probably also why you are only boosting to 7psi.
 

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Discussion Starter #7
the less backpressure thing makes sense.wow my exhaust is robbing 2-3 psi. but hey less boost and more power is better than more boost and less power.about the relocation of the IAT. is that needed?and how do i do it?


venomrogue: how do you have so much boost?i know you lost some with the head. but how are you still getting 9psi? what mods do you have?and do you recomend a dyno tune?
 

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Its not "needed" to relocate the IAT. It IS however safer. People talk about doing it all the time, but I dont know how many people actually have messed around with it on the dyno. I took my car up to FocusSport and ran it on the dyno with the IAT relocated. I was also breaking in a brand new engine, but with the IAT hooked up in the manifold, the car made 145whp with the BBK on the car. I didnt get a chance to dyno the car with it hooked up to the MAF because it was late on a friday...but I hooked it back up to the MAF when I got home and the car ran like it used to before I made the change. (according to the butt dyno). The problem with the IAT in the manifold on a JRSC is that the IAT will NEVER see low enough temps to actually advance the timing. Randy even set the tune to not pull spark until 170 degree intake air temperature. But it still only made 150whp. The problem is that it will make power still at the lower RPM's, but when you start to really spin the blower...its making so much heat that retards the timing significantly. And it did that even on the first dyno run...so its not because it built up heat....it was like that from the start. Just something to think about. Its REALLY safe...but you arnt going to be making any power. And to answer your boost question about venomrogue's car, I think that he is running either the bigger crank pulley or smaller sc pulley with his BBK.
 

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Correct, i currently have a VERY small pulley on it, but I am switching to a 2.4 blower pulley with a 5.7 crank pulley, because with that small of a pulley, you get alot of belt slippage.

And when you get it retuned with a relocated IAT you want to set it to where it wont pull spark till around 190ish or so, or just set a water/meth injection system to kick in at 75% WOT to keep the temps down (which is what is being installed next week for me) I plan on using my washer fluid resivouir as the water/meth resiuviuor instead of the small ass one that comes with the snow kits, so i can use it alot more.

Using a relocated IAT, you can set your tune around the water/meth injection without becoming "married to the bottle", because if your WM fails, then the motor pulls an assload of timing to save itself. This is the reason i relocated mine, well that, and i upgraded to a 90mm MAF that didnt have the 6pin connector which is needed for the MAF IAT [:D]
 

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Discussion Starter #10
no one here is good with the focus. its all hondas and nissans as usual. can i just go to a dyno and have them tune my car or do they need an sct or somekind of focus tunning software?
 

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SCT or diablosport is the easiest...everything else costs twice as much.
 

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VenomRogue said:
Correct, i currently have a VERY small pulley on it, but I am switching to a 2.4 blower pulley with a 5.7 crank pulley, because with that small of a pulley, you get alot of belt slippage.

And when you get it retuned with a relocated IAT you want to set it to where it wont pull spark till around 190ish or so, or just set a water/meth injection system to kick in at 75% WOT to keep the temps down (which is what is being installed next week for me) I plan on using my washer fluid resivouir as the water/meth resiuviuor instead of the small ass one that comes with the snow kits, so i can use it alot more.

Using a relocated IAT, you can set your tune around the water/meth injection without becoming "married to the bottle", because if your WM fails, then the motor pulls an assload of timing to save itself. This is the reason i relocated mine, well that, and i upgraded to a 90mm MAF that didnt have the 6pin connector which is needed for the MAF IAT [:D]
careful where you put the w/m nozzle, if it's before the TB it will flood and short the TPS...at least thats my experience...
 

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My water/meth nozzle will be after the blower rotors, in the manifold itself. you dont want cold liquid hitting very hot blower rotors, bad things happen.
 
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