Question: AVNT4094/vs cheetah ?

D-MAX Mafia

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Nov 4, 2009
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Its throwing a MAF sensor code and engine under boost. I just cleaned the MAF waiting on the filter to dry so i can put it on and see if that helps. But its still only boosting to 10 pounds and thats at 3000 rpms. I'd like to see around 30 psi. I checked for leaks and everything is tight so i'm guessing its the tune?
 

D-MAX Mafia

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Nov 4, 2009
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No more codes but it still won't spool up till 3000 rpms. Boost is coming up to 20 psi but its right before it shifts.
 

D-MAX Mafia

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Nov 4, 2009
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Yeah everything is working right. I'm not throwing anymore codes it just won't spool. The tune is just a 100 horse DD tune with the LB7 idle and turbine brake, both of these functions are working so i know the vanes are moving. I pulled the turbo apart to port the turbine housing so i was initially worried that i put it back together wrong but since the vanes are actuating i don't think thats the case. Cruising speed is awesome egts are low and it gets down the road good until I drop the hammer. Lots of smoke! Do i need to tighten up the vanes in the tuning?
 

knagel

weakest link finder
Jun 4, 2007
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Yeah everything is working right. I'm not throwing anymore codes it just won't spool. The tune is just a 100 horse DD tune with the LB7 idle and turbine brake, both of these functions are working so i know the vanes are moving. I pulled the turbo apart to port the turbine housing so i was initially worried that i put it back together wrong but since the vanes are actuating i don't think thats the case. Cruising speed is awesome egts are low and it gets down the road good until I drop the hammer. Lots of smoke! Do i need to tighten up the vanes in the tuning?

Tighten your vains to 85% up to 1600 RPM's and see if this helps. If so then you need to work with you vain tables for FP and boost. You can go to 95% at low RPM's and then start opening them up to like 75% by 1800 RPM. If not, then something isn't right with the turbo or you hooked something up wrong. I was able to make 38-42 lbs boost with my VN4094 no problem.

Make sure you have changed your desired boost tables also.
 

knagel

weakest link finder
Jun 4, 2007
221
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Central, Iowa
The LB7 idle thing may be working against you also because to get that the vains are completely open then when you go to take off they have to close to spool. I would let the LB7's keep their idle;) or go to a big single non VN to get it
 

sweetdiesel

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Aug 6, 2006
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Tighten your vains to 85% up to 1600 RPM's and see if this helps. If so then you need to work with you vain tables for FP and boost. You can go to 95% at low RPM's and then start opening them up to like 75% by 1800 RPM. If not, then something isn't right with the turbo or you hooked something up wrong. I was able to make 38-42 lbs boost with my VN4094 no problem.

Make sure you have changed your desired boost tables also.

Any idea of the drive pressure when you do that?

I've always strived for the lowest vp to get lower dp
 

MarkBroviak

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May 25, 2008
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Any idea of the drive pressure when you do that?

I've always strived for the lowest vp to get lower dp

Alot more than 2:1, lol. Best thing to do when tuning one of these VVT's is use a dp guage. Getting them as close to 1:1 as possible is the best case senario for power production without losses.

bigmackmiller Quote:
Originally Posted by MarkBroviak
PS- Brayden, I am coming for that quarter mile time...
I did 12.19 in ECSB LLY single pumped with my 65mm STG2 2.6, I think I can get to your time after sled pulling is over...

Uh oh! show down in Nap Town!

Lol, actually ended up running 11.93 at 111.9mph in that truck. I plan to take the VVT record with my 2.6 Stg2 on my 2wd LBZ single pumped here in the very near future...:D
 

paint94979

Beer Nazi
Sep 18, 2006
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Alot more than 2:1, lol. Best thing to do when tuning one of these VVT's is use a dp guage. Getting them as close to 1:1 as possible is the best case senario for power production without losses.

bigmackmiller Quote:
Originally Posted by MarkBroviak
PS- Brayden, I am coming for that quarter mile time...
I did 12.19 in ECSB LLY single pumped with my 65mm STG2 2.6, I think I can get to your time after sled pulling is over...

Uh oh! show down in Nap Town!

Lol, actually ended up running 11.93 at 111.9mph in that truck. I plan to take the VVT record with my 2.6 Stg2 on my 2wd LBZ single pumped here in the very near future...:D

Mark a little off topic but what were the break downs of that 11.93 pass? That is amazing ET for the MPH that is for sure.:thumb:
 

MarkBroviak

DMax Junkie
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May 25, 2008
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Danville Indiana
Mark a little off topic but what were the break downs of that 11.93 pass? That is amazing ET for the MPH that is for sure.:thumb:

Stock LLy engine with DP 2.6 Stg2 w/LBZ mouthpiece AEM Bruteforce LBZ intake, DP 60% inj, Dual DP Modded LBZ pumps fed by Fass 200, BD Manifold, AFE intercooler pipe, SCIV w/5star & copilot, 4.10 gears on 35" BFG Alt's on H2's and tune by me. It was actually a sled pulling truck but JT let me drag race it to prove my chargers are alot more than just hype like some wanted people to think. I just hit a personal best today with my 68mm STG2 with a 2.6 cover at 705rwhp 1300+ftlbs on a built LLY dual fueled truck. Truck has 4.56 gears and 33" tires. This is todate the highest hp I have made out of any of the 4094 sized compressors. I am very happy with the results of it.:thumb: http://www.youtube.com/watch?v=2f6iRtDhEkQ
 

D-MAX Mafia

Hood down, smoke up!
Nov 4, 2009
1,112
13
38
Phoenix
Tighten your vains to 85% up to 1600 RPM's and see if this helps. If so then you need to work with you vain tables for FP and boost. You can go to 95% at low RPM's and then start opening them up to like 75% by 1800 RPM. If not, then something isn't right with the turbo or you hooked something up wrong. I was able to make 38-42 lbs boost with my VN4094 no problem.

Make sure you have changed your desired boost tables also.


What should the desired boost be? The current setting is 45 but my factory charger only made 22 on this tune. What all tables do i adjust? Today is the first time i really tried to work on a tune i was changing all kinds of stuff to get it to work! I was told over on the Diesel Place forum that the turbo should have spooled to 30 psi no problem on a factory tune. Is this true?
 

paint94979

Beer Nazi
Sep 18, 2006
11,715
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What should the desired boost be? The current setting is 45 but my factory charger only made 22 on this tune. What all tables do i adjust? Today is the first time i really tried to work on a tune i was changing all kinds of stuff to get it to work! I was told over on the Diesel Place forum that the turbo should have spooled to 30 psi no problem on a factory tune. Is this true?

i would have someone build you a tune... you would be much happier in the end