Spooling twins

TROJAN366

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
I went to the track today and unfortunately blew a boot about 300 feet into my first pass. I left at about 10 psi and the truck just seemed dead. It didn't really spool until it shifted to second. I used to leave at 10-12psi with this 72 as a single and it launched like a bat out of hell. Should I be waiting to get more heat in the exhaust or building more boost before I leave with twins??
 
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Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,683
5,838
113
Phoenix Az
Dyno is a whole different thing comparing to spool up if the operator can't load the truck enough
 
Evan@InglewoodTrans

Evan@InglewoodTrans

yerp
Vendor/Sponsor
Aug 5, 2010
3,118
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Western MA
TROJAN366 said:
I went to the track today and unfortunately blew a boot about 40" feet into my first pass. I left at about 10 psi and the truck just seemed dead. It didn't really spool until it shifted to second. I used to leave at 10-12psi with this 72 as a single and it launched like a bat out of hell. Should I be waiting to get more heat in the exhaust or building more boost before I leave with twins??
Click to expand...

What converter are you running? You need to try and leave a little higher and see if you still fall under the chargers.
 
H

Hot COCOAL

May the farce be with you
Jun 9, 2012
4,433
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0
I'm wondering if these experiences aren't a good reason to stay with a VGT charger as the secondary...
Wouldn't keeping the secondary a VGT and gating the excess drive pressure to the primary help with spooling?
 
paint94979

paint94979

Beer Nazi
Sep 18, 2006
11,715
8
38
37
I doubt you were leaving hard enough. I usually leave around 15-18 psi on my 75mm and it runs good. Anything under 15 and its a dog
 
TROJAN366

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
I guess next time I go up I'll start around 15psi. I figured I'd make a bunch of passes and work my way up to 15-18 but just thought it was odd.

Converter is an mlg-x
 
Cknight199

Cknight199

New member
Aug 23, 2012
1,827
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Salt Lake City, Utah
I've noticed (since switching to fixed vane) that launching is harder, and rather than building 12 psi and launching like I had my vvt, it's almost better for me to launch now at 18 psi and let off the brakes a bit slower so I don't lose traction, but can still stay ontop of the charger. Anything below 16 psi on this s475 and it falls on it's face.
 
Subman

Subman

Old Geezer
Jun 27, 2008
3,233
10
38
80
Madras, OR, Pahrump NV
Obviously depends on the stall of your converter, my MPI setup on White Out is a 4094 over a 5533 and it spools great at any DA. I leave the line at 20psi for my best 60' times.
 
TROJAN366

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
Mounting up the slicks tonight and taking another shot at the track tomorrow. Been busy as hell but I'm hoping to finally get on the fast 50 list. I've been having a blast with the truck and everything seems to be working well. As long as nothing dumb bites me in the ass (like a blown boot last time) I should be able to put this big girl in the tens!
 
smkndmax05

smkndmax05

"Smoked Out"
Feb 17, 2011
479
0
0
Indiana
25lbs here on the single. 1.46 60' and that was second gear start and a 1056. Good luck!


Sent from my iPhone using Tapatalk
 
moparkxracer

moparkxracer

Well-known member
Jun 25, 2010
2,309
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48
Out and about
Top 50

I'd like to make that list too.
TROJAN366 said:
Mounting up the slicks tonight and taking another shot at the track tomorrow. Been busy as hell but I'm hoping to finally get on the fast 50 list. I've been having a blast with the truck and everything seems to be working well. As long as nothing dumb bites me in the ass (like a blown boot last time) I should be able to put this big girl in the tens!
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