Looking for missing power after 122HH upgrade...
07-08-2008, 05:57 PM
#11
07-08-2008, 07:15 PM
#12
When you drop the power band down, and dont change the cam, things change. Upping the boost does not always mean a gain, it just means more heat in that type of blower. You need to see your old boost graph versus the new boost graph to really know. You are only talking a peak number of boost. It hits in all different spots on the graph with a blower like that. A dyno is a representation of how far up can you make power, hence the reason why you see the difference up top. Because its just that, a dyno. If you can continue to make power up top effectivley, then you show more on a dyno. Thats all. It means nothing more than that. If you make more down low and through the area where it only matters, then you are doing better. Building a setup for a truck with only a peak dyno number in mind will only give you a disapointing result in how it runs. Sure its fun to see a number, but if I were you and I made a ton more power down low, I would be happier with this setup than the last.
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Also, I may be expecting different results as I have been comparing my j-tube inlet setup to the front inlet setups. I guess I need to get more details regarding iats, boost, fuel pressure and AFR...if all seems in line then we'll find out if the 8" crank pulley will be another "Nope, not it."
07-08-2008, 07:46 PM
#13
First, the build that the kit is installed on:
2001 GMC Yukon: LS6 block, Eagle 4" crank, Crower 6.125" rods, Diamond -7cc pistons, AFR 225 72cc heads with 8017 springs, Siemens 60# inj, LPE GT2-3 cam, Comp 850 lifters, Crane 1.7 Gold Race rockers, JBA Ti Ceramic coated hdrs, Magnaflow catted y-pipe, Corsa Touring catback, Alkycontrol meth inj, Volant CAI, FLT Level 4 4L60e, Auburn Pro LSD w/ 3.90 gears, 20x9" Denalis Repros/275-45R20 General UHPs.
Got the 122HH upgrade installed and tuned. Although we requested the kit be pulley'd for 10# peak boost, the 3.0" pulley that it came with gave 6.5# boost and 507rwhp/515rwtq. Not a bad start and we were looking forward to a pulley swap to get our 10# and 600/600!
We were shipped a 2.85" pulley and got a whopping 8# boost. We picked up 40rwtq down low but actually lost some up top
? The tune is dialed in, so we are at a loss to determine where the problem lies. We removed the CAI to see what that would do...no change. We discussed the MAF being a restriction but there are many folks here putting down 600rwhp and running the 85mm MAF, so we don't believe that is the issue. We are going to go to an 8" balancer/pulley to see what that picks up, but it still does not answer what is going on with the top end.
Two questions:
1) Anyone have any thoughts on the missing HP?
2) What are the options for 8" balancer/pulleys? I know about ECS, and ASP is modifying oem balancers to 8"...does ATI make one, any others?
2001 GMC Yukon: LS6 block, Eagle 4" crank, Crower 6.125" rods, Diamond -7cc pistons, AFR 225 72cc heads with 8017 springs, Siemens 60# inj, LPE GT2-3 cam, Comp 850 lifters, Crane 1.7 Gold Race rockers, JBA Ti Ceramic coated hdrs, Magnaflow catted y-pipe, Corsa Touring catback, Alkycontrol meth inj, Volant CAI, FLT Level 4 4L60e, Auburn Pro LSD w/ 3.90 gears, 20x9" Denalis Repros/275-45R20 General UHPs.
Got the 122HH upgrade installed and tuned. Although we requested the kit be pulley'd for 10# peak boost, the 3.0" pulley that it came with gave 6.5# boost and 507rwhp/515rwtq. Not a bad start and we were looking forward to a pulley swap to get our 10# and 600/600!
We were shipped a 2.85" pulley and got a whopping 8# boost. We picked up 40rwtq down low but actually lost some up top
? The tune is dialed in, so we are at a loss to determine where the problem lies. We removed the CAI to see what that would do...no change. We discussed the MAF being a restriction but there are many folks here putting down 600rwhp and running the 85mm MAF, so we don't believe that is the issue. We are going to go to an 8" balancer/pulley to see what that picks up, but it still does not answer what is going on with the top end.Two questions:
1) Anyone have any thoughts on the missing HP?
2) What are the options for 8" balancer/pulleys? I know about ECS, and ASP is modifying oem balancers to 8"...does ATI make one, any others?
07-08-2008, 08:31 PM
#14
Wow, I am a little surprised. It seems that it is either the blower efficiency (maybe there is extremely high IAT's and timing is being pulled) or you are not able to spin the blower fast enough with the current crank pulley.
I would check the IAT's and A/F and go from there. I made 515rwhp on my lq4 on a dynojet with the 22's and 545rwhp on Rick's dynapack. Something is wrong. I think it has to wth the ability to spin the blower fast enough. The front inlet/rear drive have a huge advantage by being able to overdrive there blower before changing a blower pulley or crank pulley.
I would check the IAT's and A/F and go from there. I made 515rwhp on my lq4 on a dynojet with the 22's and 545rwhp on Rick's dynapack. Something is wrong. I think it has to wth the ability to spin the blower fast enough. The front inlet/rear drive have a huge advantage by being able to overdrive there blower before changing a blower pulley or crank pulley.
07-09-2008, 02:22 AM
#16
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I know I had a ton of slip on my setup when I had the maggie. Sometimes I was at 8# and sometimes it was at 6# and it always made a ton of heat. The blower was too small for the motor and worked over time, and the belt slip didnt help. You can switch to the inovators west 8" pully and I suggest going to a 8 rib pully opposed to the factory six rib at the same time to try and cure the problem. Or go with the new 2300TVS.
07-09-2008, 05:25 AM
#17
The graph I have posted is of the 383/122HH has both the 6.5# (blue) and 8# (red) runs. Although I whole-heartedly agree with the "be happy with the better low end increases" (where the power is more usable), at this time I'm attempting to use the graphs as a tool to determine if I have something amiss--possible intake restriction(s), valve float, belt slip, high iats, etc.
Also, I may be expecting different results as I have been comparing my j-tube inlet setup to the front inlet setups. I guess I need to get more details regarding iats, boost, fuel pressure and AFR...if all seems in line then we'll find out if the 8" crank pulley will be another "Nope, not it."
Also, I may be expecting different results as I have been comparing my j-tube inlet setup to the front inlet setups. I guess I need to get more details regarding iats, boost, fuel pressure and AFR...if all seems in line then we'll find out if the 8" crank pulley will be another "Nope, not it."
The belt is not slipping, the IATs aren't pulling timing (I have a boost cooler), and the timing and fuel logs are right on. Allen's tuned more than a few of these. He says the tune is right on the money. I believe him.
Last edited by old motorhead; 07-09-2008 at 05:44 AM.
07-09-2008, 01:47 PM
#18
Didn't mean to hijack your thread. Just agreeing with you. Something ain't right. If the Magnuson boys had told me that I'd realize a 30 hp increase by "upgrading" to the 122, I wouldn't have bothered. Money and time could have been better used on other pursuits.
The belt is not slipping, the IATs aren't pulling timing (I have a boost cooler), and the timing and fuel logs are right on. Allen's tuned more than a few of these. He says the tune is right on the money. I believe him.
The belt is not slipping, the IATs aren't pulling timing (I have a boost cooler), and the timing and fuel logs are right on. Allen's tuned more than a few of these. He says the tune is right on the money. I believe him.
We aren't done tweaking just yet, and an SD tune and possibly a more performance oriented cam (I have a Synergy 226/230-590/590-114 LSA that I could throw in as well) is not out of the question either. But first we'll try the crank pulley and see what it does.
