Boosting Question
10-06-2010, 08:13 PM
#1
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Boosting Question
Hey guys I have a 86 951 with Stage 2 Autothority chips, MBC, new 15psi wastegate, hv bosch fuel pump... I was wondering it I add a 3 bar regulator would I be able to up the boost to 17 safely? I never run the car to redline during boost but am in the 5k RPM range.
I am running a k26/6 at the moment
I am running a k26/6 at the moment
10-06-2010, 08:22 PM
#3
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The information on the chips pertains to the fuel pressure regulator.
If your chips read 2.5 bar, you need to stick with it.
The ignition timing curve written is also intended to operate within a narrow margin - 17 is pushing it on both counts.
Finally - if you have a 26/6, you will realize little gain at 17 psi - you will have hot air.
If your chips read 2.5 bar, you need to stick with it.
The ignition timing curve written is also intended to operate within a narrow margin - 17 is pushing it on both counts.
Finally - if you have a 26/6, you will realize little gain at 17 psi - you will have hot air.
10-06-2010, 09:04 PM
#4
Race Director
The information on the chips pertains to the fuel pressure regulator.
If your chips read 2.5 bar, you need to stick with it.
The ignition timing curve written is also intended to operate within a narrow margin - 17 is pushing it on both counts.
Finally - if you have a 26/6, you will realize little gain at 17 psi - you will have hot air.
If your chips read 2.5 bar, you need to stick with it.
The ignition timing curve written is also intended to operate within a narrow margin - 17 is pushing it on both counts.
Finally - if you have a 26/6, you will realize little gain at 17 psi - you will have hot air.
10-06-2010, 09:13 PM
#5
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I was running 17psi all this year and the PO did the same for over a year with the 26/6. "Was" is the key word as i just popped the head gasket last weekend. In hindsight )including a couple rennlist warnings and discussions since blowing the gasket) the back pressure was surely too high at that psi with the 26/6.
I can see that a WB would have been helpful though i still wouldn't have known what backpressure was.
Not whining here..it will go back new and improved. My plan is a slightly larger turbo running about 15psi until I can go with larger injectors and WB.
Then again...what do I know!
I can see that a WB would have been helpful though i still wouldn't have known what backpressure was.
Not whining here..it will go back new and improved. My plan is a slightly larger turbo running about 15psi until I can go with larger injectors and WB.
Then again...what do I know!
10-06-2010, 11:30 PM
#6
I'm pretty sure the Autothority Stg 2 chips are not mapped for 17lbs of boost. They came with a jetted banjo bolt to use with the stock CV/wastegate. Never had a boost gauge while I had them so I don't know what boost was set at, but I don't think it was anywhere near 17, as I only ran 15 with my MAF/Max chips/Tial/MBC set-up and the car felt considerably faster.
10-06-2010, 11:49 PM
#7
Race Director
APE Chips can be run upto 19psi, some say 21psi, but Minh told me long ago never past 19.......although as we all know it is not recommended for the obvious reasons 
Mine ran extremely well at 17, a bit lean, but nothing close to damaging as some others experienced.
Mine ran extremely well at 17, a bit lean, but nothing close to damaging as some others experienced.
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10-07-2010, 12:31 AM
#8
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I recently saw someone's dyno on here that had APE chips and was pushing 17/18psi and he pulled a decent dyno, it was looking a little rich towards the end when boost dropped in the higher RPMs... he had a 3bar FPR... so maybe I should get an adjustable FPR from lindsey and a WB gauge to ensure I'm where I need to be.
10-07-2010, 01:43 AM
#10
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Yep, exactly. Even if you get the AFRs good with a piggyback, the timing won't be correct (too much) for the higher boost.
10-07-2010, 01:48 AM
#11
You would more than likely be better spending the little extra money now for proper chips tuned to your set-up. Turning up the boost past what chips are meant for may lead to catastrophic results.
Only trying to help, not hate.
Only trying to help, not hate.
10-07-2010, 08:43 AM
#12
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Sorry - let me make that more clear.
The chip has code for the fuel pressure regulator - if your chip is made for a 2.5 bar regulator, you can't just stick a 3 bar in there....for obvious reasons.
Likewise the boost level and injector size....these parameters are not arbitrary.
This is why it is ALWAYS necessary to know exactly what is written on your chip. Buying 5th/6th/7th hand chips is risky.
The chip has code for the fuel pressure regulator - if your chip is made for a 2.5 bar regulator, you can't just stick a 3 bar in there....for obvious reasons.
Likewise the boost level and injector size....these parameters are not arbitrary.
This is why it is ALWAYS necessary to know exactly what is written on your chip. Buying 5th/6th/7th hand chips is risky.
10-07-2010, 08:46 AM
#13
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Thread Starter
No worries, I understand where you guys are coming from and the input is important. I don't have the experience many of you have with these cars and especially upgrading them, so I value anything said. I think I will keep the boost at 15psi until I have the proper setup.
10-07-2010, 11:57 AM
#15
Race Car
This was off their site,
STAGE II - 48 hp increase
The Stage II DME and KLR chip set come with a new Banjo Boost bolt that has an air correction jet installed in it to bump up the boost pressure to 1.0 bar (14.7) psi. With over 40 hp being gained, this kit provides you the best bang for the buck and makes a true seat of the pants difference. Be prepared to hold on to the steering wheel as your car accelerates through the gears.
STAGE II - 48 hp increase
The Stage II DME and KLR chip set come with a new Banjo Boost bolt that has an air correction jet installed in it to bump up the boost pressure to 1.0 bar (14.7) psi. With over 40 hp being gained, this kit provides you the best bang for the buck and makes a true seat of the pants difference. Be prepared to hold on to the steering wheel as your car accelerates through the gears.