VP44 guys help me on this

bling

bling

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Nov 30, 2009
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Ok i took my truck out the 1/8 mile this weekend to shakedown the setup in my sig. My best run was a 9.3 which is depressing considering the setup. My real question is what stall are u guys running in your converters with a similar size charger. I really coulndt stay on top of the charger. My boost would read about 45 at wot and backpressure was the same basicly. It would launch good but it just isnt driving the charger at all. Im blacking out the strip the whole way down. The stall speed in my converter is really high. I cant tell u exactly cause i dont have the papaer work but a buddy of mine uses the same stall for a 3.0 12 valve puller. we tried it thinking we were gonna go 2.8 but ended with my 67mm. It feels like the converter is so loose that i cant even build enough back pressure to really spin the turbo. I sat on the line at 2800 rpm and like 5 lbs of boost. i max out at 3200 with the drag comp. Its a tcs converter and i get one free converter change. I feel like i need to go back to stock or closer so it will put load on the truck and build more drive pressure. What do u guys think. I may be able to post video of one run to really show u.


please help me
 
heres a video of one run [ame="http://www.youtube.com/watch?v=Rvty0NE7PBw&feature=player_profilepage"]http://www.youtube.com/watch?v=Rvty0NE7PBw&feature=player_profilepage[/ame]
 
While we can recommend something, your best bet is to talk to the guy who is going to build your converter.
 
BgBlDodge said:
While we can recommend something, your best bet is to talk to the guy who is going to build your converter.
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granted yes. Im just trying to get the feelers out there and see what others are running since this isnt a pioneering advanture, I know there are similar setups running now.
 
Im running a triple disc from Goerend. Im not sure what the stall speed is but I dont think its to high. My 1/8 mile time is 8.44 with a 1.887 60' time. Which isnt my best 60' either. This was done with the setup in my sig but with my stock cam. I dont have a new time yet with the Killer B.
 
i ran the truck like 8 times that day and really watched the back pressure and boost gauge. When the tc locks it falls on its face. Its like the gap from wot unlocked and then locked is too much load all at once and i snuffs the charger right out. I feel like if i had 60 to 70 lbs drive pressure and fifty pounds boost it wouldnt fall under the charger when it locks.
 
Im no expert by any means, but If you gave it a little more time in the prestage to spool. Could you launch with more boost? I launch at 15psi. I have launched at 20psi but I get a better 60' with 15psi. Also it may help to know what your current stall speed is and if your converter is a single or triple disc. Also what are the full specs on your charger? 67mm compressor and what turbine wheel?
 
Maybe close to a v10 stall? Maybe try a stock diesel stall. When is the converter locking?
 
First couple guesses ar is too large on that charger

Second the converter is too tight

Just went through the same issues myself
 
MCForstenRacing said:
Mud tires and a lift kit don't help either. put an exhaust system on that truck bro
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thats a leveling kit and no lift but i didn even plan on running but the owner said we could for free so i went for it. .68 ar is pretty tight and its a triple disc with a v10 stall now that i checked it. I dont see how that converter is to tight. I can power brake to 2800 and the tires dont brake loose and it only has 5lbs of boost. Its almost free reving

the only tighter ar option is .58
 
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kleann said:
Maybe close to a v10 stall? Maybe try a stock diesel stall. When is the converter locking?
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converter locks at the end almost of the eighth. Ive tried locking it early with the switch and it falls on its face. I feel like i either need more rpm or more drive pressure
 
smoken02 said:
Im no expert by any means, but If you gave it a little more time in the prestage to spool. Could you launch with more boost? I launch at 15psi. I have launched at 20psi but I get a better 60' with 15psi. Also it may help to know what your current stall speed is and if your converter is a single or triple disc. Also what are the full specs on your charger? 67mm compressor and what turbine wheel?
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charger specs

comp wheel
67 ind 84 exd

turbine wheel
74 ind 64 exd .68 ar with polished h cover
 
I agree with you on the charger that ar is really tight why? You are throwin quite a bit of fuel at that thing what are you running for electronics? Interesting sized turbo if I read your Sig and what you've said correctly
 
MCForstenRacing said:
I agree with you on the charger that ar is really tight why? You are throwin quite a bit of fuel at that thing what are you running for electronics? Interesting sized turbo if I read your Sig and what you've said correctly
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electronics is just a drog comp and i only have it turned on for the rpms

no timing and level one only. ive tried a few combos at the track but nothing seemed to help. We went tight on the exhast side cause we were worried about spooling issues with the limited rpm. We were thinking that it may over spin it in the process so we had an external wastegate installed and i have it blocked right now. no where near enough drive to open it yet. the turbo is all precision. based off a garret gt38 but all there parts.
 
i think you are killing yourself with that charger. You are capable of spooling a lot more turbo then that. I am in no way a turbo expert and would never tell some one that i am. I have experimented with quite a few different setups and that charger something in my gut tells me it is way too small. I have spooled T6 based 71/77 ontop of an s4t 86/98 with ease. Also single chargers as large as 75mm. What about a 66-67 with somewhere in the 70/75 range exhaust with an 80ar? Again i could be totally off base but im confident that turbo is killing you way too small.
 
MCForstenRacing said:
i think you are killing yourself with that charger. You are capable of spooling a lot more turbo then that. I am in no way a turbo expert and would never tell some one that i am. I have experimented with quite a few different setups and that charger something in my gut tells me it is way too small. I have spooled T6 based 71/77 ontop of an s4t 86/98 with ease. Also single chargers as large as 75mm. What about a 66-67 with somewhere in the 70/75 range exhaust with an 80ar? Again i could be totally off base but im confident that turbo is killing you way too small.
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i know what you are saying. But you would think a turbo that is too small would spin like crazy. My stock tubo would scream with all that fuel. Monster mike said that i could spin a 71mm with ease. Somthing is not adding up. Im gonna pressure test it tommorow and see if i have a boost leak somwhwere. I know i dont have an exhaust leak. i would see the soot somwhere...as far as the turbo we thought i would spin the crap out of that thing thats why we got the wastegate. I have a few options i can change on my current turbo as far as compressor wheels and housings. i still feel i need to tighten the coverter so it will load the truck up more. It free revs way to much and wont build boost. im gonna wait to make that move but it isnt out of the question.

The idea behind this turbo was 2.6 vp pull/drag truck with less than 4k rpm. U figure tighten up the exhaust so u can spin it with less rpm and a lot of fuel and waste what isnt needed and still protect the charger from over speeding. Its acting like a 2.6 pulling turbo with a giant exhaust meant for a 12 valve with 5000 rpm.
 
I do agree something is not adding up. I would do the same and pressure test the system. I would change the charger up go bigger. Loosen up the converter a bit. I know we are limited in rpms but don't let that discourage you when building the turbo for your truck. The more you lug that thing down the more fuel she is going to pump.
 
MCForstenRacing said:
I do agree something is not adding up. I would do the same and pressure test the system. I would change the charger up go bigger. Loosen up the converter a bit. I know we are limited in rpms but don't let that discourage you when building the turbo for your truck. The more you lug that thing down the more fuel she is going to pump.
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oh yeah. the challenge makes it fun. if it was easy then everybody would own a vp. Im gonna play with it some. pressure test for sure and go from there. ill keep u posted. Thanks for the help though
 
Shoot me with an email coleforsten@gmail.com with you combo/setup we have been through a lot with the vp and had some good success I would be happy to shoot you over some suggestions and recommendations if you would like. If not no worries just offering a helping hand
 
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