Easy solution for D1's and cruise bucking
#1
Easy solution for D1's and cruise bucking
I had a car recently that got a D1 on his H/C car.We installed the kit and there was some real bad bucking at cruise.Found out the MA was getting too much air(not enough bypass).After figuring it out I ordered another 1 1/2 bypass valve assembly from ATI.
We installed this on the pass side up pipe midway up the radiator by drilling the pipe,welding a 1 1/2 fitting then installing the valve and pointing it at the ground under the radiator.The vacuum was Tee'd off the other valve.
The car drives perfect now.No bucking at all,start up is great..
Figured I'd pass this on
We installed this on the pass side up pipe midway up the radiator by drilling the pipe,welding a 1 1/2 fitting then installing the valve and pointing it at the ground under the radiator.The vacuum was Tee'd off the other valve.
The car drives perfect now.No bucking at all,start up is great..
Figured I'd pass this on
#2
8 Second Club
iTrader: (34)
you can just up the MAF numbers up to 6Khz also and get rid of 99.9% of the weirdness with an ATI. If you look the MAF numbers in that range are lower then a stock car and that drops the PW way too far at idle and part throttle and when the car pulls fuel to drop the ltrims the car just dies. It doesnt make sense since you would think the numbers would be higher since there is a lot of air moving there with the ATI but with the throttle blade closes/almost closed it must get some kind of reversion thing happening. C5 MAFs are ~a foot away from the TB and they dont seem to have that problem..
More bypass is the proper, although more expensive, way to do it though..
More bypass is the proper, although more expensive, way to do it though..
#5
Been over a week and still great..
Yes,you can play with the MAF table but that isn't really a permanent fix..This is actually cheaper than what I've read of people going with $500+ valves..
I've got a few E-mails about how to do this,hopefully next weekend I'll take some pics so people have an idea on how it goes together,really simple when you see it.
Yes,you can play with the MAF table but that isn't really a permanent fix..This is actually cheaper than what I've read of people going with $500+ valves..
I've got a few E-mails about how to do this,hopefully next weekend I'll take some pics so people have an idea on how it goes together,really simple when you see it.
Trending Topics
#8
8 Second Club
iTrader: (34)
Not sure what you mean by the MAF table changes not being permanent, its not something will be learned out with the ltrims - on the contrary - it makes the ltrim numbers very consistant across the board. It just takes a little time to do it. I have 4 ATI cars running around that idle/drive like stock and no one has complained.
Only problem is if you pulley up a bunch it will change things a bit, I do think having more bypass is the right way to do it (or move the MAF away from the TB/change to a draw through) but its hard to get any easier then LS1edit
Only problem is if you pulley up a bunch it will change things a bit, I do think having more bypass is the right way to do it (or move the MAF away from the TB/change to a draw through) but its hard to get any easier then LS1edit
Originally Posted by Slowhawk
Been over a week and still great..
Yes,you can play with the MAF table but that isn't really a permanent fix..This is actually cheaper than what I've read of people going with $500+ valves..
I've got a few E-mails about how to do this,hopefully next weekend I'll take some pics so people have an idea on how it goes together,really simple when you see it.
Yes,you can play with the MAF table but that isn't really a permanent fix..This is actually cheaper than what I've read of people going with $500+ valves..
I've got a few E-mails about how to do this,hopefully next weekend I'll take some pics so people have an idea on how it goes together,really simple when you see it.
#10
Originally Posted by kp
Not sure what you mean by the MAF table changes not being permanent, its not something will be learned out with the ltrims - on the contrary - it makes the ltrim numbers very consistant across the board. It just takes a little time to do it. I have 4 ATI cars running around that idle/drive like stock and no one has complained.
Only problem is if you pulley up a bunch it will change things a bit, I do think having more bypass is the right way to do it (or move the MAF away from the TB/change to a draw through) but its hard to get any easier then LS1edit
Only problem is if you pulley up a bunch it will change things a bit, I do think having more bypass is the right way to do it (or move the MAF away from the TB/change to a draw through) but its hard to get any easier then LS1edit
#14
I'm running a Hot Cam (218/227 @ 50 .525" / .525" 112 LSA) and I'm experiencing really bad bucking at cruise. Hope to get something done soon to alleviate the problem.
Edit: Running a D1-SC @ 5psi
Edit: Running a D1-SC @ 5psi
#16
8 Second Club
iTrader: (34)
Originally Posted by NoGo
Or, if you want to get fancy just disable the MAF for the lower RPMs. Mine doesn't kick in until ~1800+ RPMs. Works pretty well with the supercharger strapped on. I don't have any bucking issues at least with the S/C and my cam.
#18
TECH Resident
iTrader: (3)
Join Date: Nov 2001
Location: Richmond, VA Where fast cars, well......are hard to come by.
Posts: 979
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by NoGo
Or, if you want to get fancy just disable the MAF for the lower RPMs. Mine doesn't kick in until ~1800+ RPMs. Works pretty well with the supercharger strapped on. I don't have any bucking issues at least with the S/C and my cam.
#20
Originally Posted by HUGGER ORANGE SS
Lord. I'm running the same cam as you know and I don't have any bucking effect. I am running a aftermarket BOV though. I wonder if that would have any effect.
Clint
Clint
Dyno graph in case anyone else wants to see it: http://www.outerworld.ws/dyno/1.jpg