not getting enough boost question
11-09-2009, 08:32 PM
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not getting enough boost question i have the aps twin turbo kit on my camaro..... always had it at the stock
8 lb spring with no boost controller...... would hit 8 to 9 lbs. no problem..... then i bought a manual turbonetics boost controller...... turned it in a few turns and was around 10 to 11 lbs. thought i would swap out the cheap plastic bosch valves for some billet replacments...... hooked it up like the bosch and it would spit all my boost out at 5 psi...... called the shop i bought them from and said those valves were designed to be fed from the side and vent boost out the bottom...... sounded wrong but tried it and it no longer spit out the boost....... it held it and vented only when i lifted the throttle..... but i went to the track on saturday and went 11.60 at 118..... thought it should be faster so i checked the boost on the next run and i was only getting 6 lbs. of boost...... tried cranking up the boost controller a bit and nothing... no change..... turned it in 4 times..... and nothing more than 6 lbs. of boost........ so that night i went home and put the bosch valves back in...... instantly i had 8 lbs of boost..... hit 9 a few times....... turned the boost controller up and again...... no boost over 8 this time.
so........ what the heck is going on ???
thanks,
8 lb spring with no boost controller...... would hit 8 to 9 lbs. no problem..... then i bought a manual turbonetics boost controller...... turned it in a few turns and was around 10 to 11 lbs. thought i would swap out the cheap plastic bosch valves for some billet replacments...... hooked it up like the bosch and it would spit all my boost out at 5 psi...... called the shop i bought them from and said those valves were designed to be fed from the side and vent boost out the bottom...... sounded wrong but tried it and it no longer spit out the boost....... it held it and vented only when i lifted the throttle..... but i went to the track on saturday and went 11.60 at 118..... thought it should be faster so i checked the boost on the next run and i was only getting 6 lbs. of boost...... tried cranking up the boost controller a bit and nothing... no change..... turned it in 4 times..... and nothing more than 6 lbs. of boost........ so that night i went home and put the bosch valves back in...... instantly i had 8 lbs of boost..... hit 9 a few times....... turned the boost controller up and again...... no boost over 8 this time.
so........ what the heck is going on ???
thanks,
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11-10-2009, 07:07 PM
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well..... i am having the shop i bought the billet BOV's from check them out...... but even with good functional bosch's i still cant go over 8 lbs. of boost.....has to be with the turbonetics boost controller..... being bad or not hooked up right...... the regulator has 4 ports..... i have 2 blocked and using the other 2
11-10-2009, 08:03 PM
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11-14-2009, 11:39 AM
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ok...... here is the latest update..... damn turbo's lol......
i yanked the boost controller out completely... went to a local tial supply shop
here and picked up some red springs.... suppose to be 11.5 lb. springs.
pulled out the old ones and these were huge compared to the little green ones in there...... any way....... under full load and full boost i am hitting 9 lbs. of boost on whats suppose to be a 11.5 lb spring>>>>> grrrrrrrr.... am i missing something here ? should i keep changing springs till i finally get the 10 lbs. i want ?
i yanked the boost controller out completely... went to a local tial supply shop
here and picked up some red springs.... suppose to be 11.5 lb. springs.
pulled out the old ones and these were huge compared to the little green ones in there...... any way....... under full load and full boost i am hitting 9 lbs. of boost on whats suppose to be a 11.5 lb spring>>>>> grrrrrrrr.... am i missing something here ? should i keep changing springs till i finally get the 10 lbs. i want ?
11-14-2009, 11:58 AM
#14
They are approximate but should be close. You can usually get double spring pressure with boost controller. Remember boost controllers can't lower boost under the spring can only raise it higher.
If you have the proper springs and cannot raise boost with the controller than likely you have boost leak issues or turbo issues.
Also think it matters where you read the boost from. If the gates are 7psi and you read from intake after going thru the intercooler would think you would get a bit lower do to intercooler loss . So you might need 12psi spring to get 10psi on guage if intercooler loses 2psi. Just an example..not sure how much a particular intercooler will lose.
Still can't see a bit problem here. What do you want to run max with your setup..15psi max..20psi max. ..Also if you are going to do staging thing with boost with say eboost two remember lowest stage can't be less then minimum spring pressure.
So if you wanted to stage then say 7 base spring and maybe could stage 7, 9, 12,15 type of thing. I have not tried staging with my eboost but plan on trying it.
If you don't want to run a controller at all then guess you can keep upping the springs till you get where you want to be. But if you want to take the boost up then again cant' see why you cant' get double spring pressure or within a pound or so.
If you are having big problems getting say 10 psi springs to go up to 18 or something then you should boost leak check things and if that checks out maybe turbo is not putting out proper boost.
I
If you have the proper springs and cannot raise boost with the controller than likely you have boost leak issues or turbo issues.
Also think it matters where you read the boost from. If the gates are 7psi and you read from intake after going thru the intercooler would think you would get a bit lower do to intercooler loss . So you might need 12psi spring to get 10psi on guage if intercooler loses 2psi. Just an example..not sure how much a particular intercooler will lose.
Still can't see a bit problem here. What do you want to run max with your setup..15psi max..20psi max. ..Also if you are going to do staging thing with boost with say eboost two remember lowest stage can't be less then minimum spring pressure.
So if you wanted to stage then say 7 base spring and maybe could stage 7, 9, 12,15 type of thing. I have not tried staging with my eboost but plan on trying it.
If you don't want to run a controller at all then guess you can keep upping the springs till you get where you want to be. But if you want to take the boost up then again cant' see why you cant' get double spring pressure or within a pound or so.
If you are having big problems getting say 10 psi springs to go up to 18 or something then you should boost leak check things and if that checks out maybe turbo is not putting out proper boost.
I
11-14-2009, 12:18 PM
#15
Big red is proper spring for 12.5. Are you checking in like third gear? Are you doing a long enough run to make sure you aren't hitting that number.
You can do a test carefully by unhooking line from turbo nipple to gate. Then see what you can get but watch things carefully. With no line and red springs you should be able to get like 20psi out of it if not 25 if the turbos could do it.
If you can't get 12 or 15 out of it then as said boost leak maybe from blow offs or somewhere else or turbo problem.I guess possibly chance of gate sticking open from oil maybe ,we know the aps like to blow oil sometimes..
Are you sure your boost guage is accurate. Maybe take readings from map sensor thru laptop if you are running 2 or 3 bar..
But really wouldn't be getting super hung up if you are pound or so off here and there.
Just get a working boost controller and you should have zero problems going up with those red springs as said to 20psi for sure if not more.
I like the turbosmart manual boost controllers. They also have to be put in the right direction between gate and turbo.
Electronic like eboost 2 or equivalent are also nice ways to go but of course a lot more money.
You could also keep running the aps bosch blow offs until you figure out this boost issue as adding aftermarket blow offs is likely confusing the issue. I do have zero problems with my turbosmart kompact direct unrecirced replacements. They are easy to adjust and work fine.
I also believe in using quailty name brand stuff especially for gates and blow offs.
We already know about knock off turbos..LOL
Gate is of course critical. I think Tomz28 had problem with his gate not holding boost and it was dirty I think maybe oil fouled?..Pretty sure he just cleaned it .
I also changed out the aps bolt /stud setup on my passenger gate so can remove it now much easier to do spring swaps even with my 4l80 swap. Drivers side is no big deal since gate faces out and have more room.But passenger was not fun with their fastening setup.Couple bucks and fixed that issue.
You can do a test carefully by unhooking line from turbo nipple to gate. Then see what you can get but watch things carefully. With no line and red springs you should be able to get like 20psi out of it if not 25 if the turbos could do it.
If you can't get 12 or 15 out of it then as said boost leak maybe from blow offs or somewhere else or turbo problem.I guess possibly chance of gate sticking open from oil maybe ,we know the aps like to blow oil sometimes..
Are you sure your boost guage is accurate. Maybe take readings from map sensor thru laptop if you are running 2 or 3 bar..
But really wouldn't be getting super hung up if you are pound or so off here and there.
Just get a working boost controller and you should have zero problems going up with those red springs as said to 20psi for sure if not more.
I like the turbosmart manual boost controllers. They also have to be put in the right direction between gate and turbo.
Electronic like eboost 2 or equivalent are also nice ways to go but of course a lot more money.
You could also keep running the aps bosch blow offs until you figure out this boost issue as adding aftermarket blow offs is likely confusing the issue. I do have zero problems with my turbosmart kompact direct unrecirced replacements. They are easy to adjust and work fine.
I also believe in using quailty name brand stuff especially for gates and blow offs.
We already know about knock off turbos..LOL
Gate is of course critical. I think Tomz28 had problem with his gate not holding boost and it was dirty I think maybe oil fouled?..Pretty sure he just cleaned it .
I also changed out the aps bolt /stud setup on my passenger gate so can remove it now much easier to do spring swaps even with my 4l80 swap. Drivers side is no big deal since gate faces out and have more room.But passenger was not fun with their fastening setup.Couple bucks and fixed that issue.
11-14-2009, 03:30 PM
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my gauge is reading boost from a vaccum port behind the intake......
i am doing a 45 roll in 3rd and standing on it till 5500 rpm , gauge reads 9 lbs.
i know the stock ls1 cant take too much boost but i would be happy with a solid 10 lbs of boost to the motor or.... maybe 11 lbs. lol i gave up on the billet blow off valves i bought found out there spring was way to weak and went back to the bosch....... i also found out that the vaccum lines going to the top of my bov's were not seeing vaccum..... the shop that installed my kit ran them to a T fitting and then to a vaccum line off a sensor mounted to my intake....... so they had no vaccum to them till maybe i turned something on...... so the bov's might have been venting back up through that top port..... as far as boost controllers go..... i think at this point i might be too tempted to turn it up and might damage something at too high a boost..... guess i should be happy with 9 lbs. but really wanted to see 10 lbs. u think i might be pushing 11 lbs. out the turbo but by the time my gauge sees it its only showing 9 lbs. ? as for changing out the springs...... its not as bad as i thought it would be....... took me 30 min. to do both sides...... i just pulled all the allen bolts out and slowly worked out the top cap past the trans...... then reversed the process.... was still a struggle but got it done .
my goal is to see a low 11 or high 10 out of this set up now..... i just went 11.60 on only 6 lbs. going to track tonight..... on 9 lbs. hopefully i do a little better . also....... i think i might have to do a gear swap..... have a th400 with 3.40 gears....going through traps at 6100 rpm . was thinking of adding a 50 shot of nitrous in 3 rd gear....... but no way with this gear set.
i am doing a 45 roll in 3rd and standing on it till 5500 rpm , gauge reads 9 lbs.
i know the stock ls1 cant take too much boost but i would be happy with a solid 10 lbs of boost to the motor or.... maybe 11 lbs. lol i gave up on the billet blow off valves i bought found out there spring was way to weak and went back to the bosch....... i also found out that the vaccum lines going to the top of my bov's were not seeing vaccum..... the shop that installed my kit ran them to a T fitting and then to a vaccum line off a sensor mounted to my intake....... so they had no vaccum to them till maybe i turned something on...... so the bov's might have been venting back up through that top port..... as far as boost controllers go..... i think at this point i might be too tempted to turn it up and might damage something at too high a boost..... guess i should be happy with 9 lbs. but really wanted to see 10 lbs. u think i might be pushing 11 lbs. out the turbo but by the time my gauge sees it its only showing 9 lbs. ? as for changing out the springs...... its not as bad as i thought it would be....... took me 30 min. to do both sides...... i just pulled all the allen bolts out and slowly worked out the top cap past the trans...... then reversed the process.... was still a struggle but got it done .
my goal is to see a low 11 or high 10 out of this set up now..... i just went 11.60 on only 6 lbs. going to track tonight..... on 9 lbs. hopefully i do a little better . also....... i think i might have to do a gear swap..... have a th400 with 3.40 gears....going through traps at 6100 rpm . was thinking of adding a 50 shot of nitrous in 3 rd gear....... but no way with this gear set.
11-14-2009, 03:45 PM
#17
If the guage is accurate ,are you speed density.if so you should be able to log boost with map..might have to play with some math to do it though..
I still thought big intercooler could cause drop in boost. Course normally you just dial up what you want with the controller. If you are dead set on x boost on the guage which is what the engine is actually seeing then put the manual controller back on there and quit messing with springs. Or to to electronic ,ones like eboost are better than most manual types. Lots more features.
If you are on stock engine then wouldn't be too greedy. Unless you have money for back up when this motor goes boom.Stock pistons are fragile things.Seen a few too many blown stock ringlands but not my car.I went forged engine right away.
Best of luck at the track and don't think 3.40 would be problem with small shots .You should still have lots of mph potential with 3.40 and reasonable size tire..
Course again if you are stock engine you want to keep rpm down.I figure am safe to 7000 once in awhile so that does give me more top end potential. There are calculators to help you figure out your mph give or take converter slippage I guess.
I still thought big intercooler could cause drop in boost. Course normally you just dial up what you want with the controller. If you are dead set on x boost on the guage which is what the engine is actually seeing then put the manual controller back on there and quit messing with springs. Or to to electronic ,ones like eboost are better than most manual types. Lots more features.
If you are on stock engine then wouldn't be too greedy. Unless you have money for back up when this motor goes boom.Stock pistons are fragile things.Seen a few too many blown stock ringlands but not my car.I went forged engine right away.
Best of luck at the track and don't think 3.40 would be problem with small shots .You should still have lots of mph potential with 3.40 and reasonable size tire..
Course again if you are stock engine you want to keep rpm down.I figure am safe to 7000 once in awhile so that does give me more top end potential. There are calculators to help you figure out your mph give or take converter slippage I guess.
11-15-2009, 03:44 AM
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ok....... took it to the track tonight. went 11.0 at 126 with a 1.75 60 ft
leaving at 2400 rpm foot braking it. no boost on the launch......damn....... so close to a 10 second pass...... not bad for a bone stock motor on 9 lbs. i guess.
leaving at 2400 rpm foot braking it. no boost on the launch......damn....... so close to a 10 second pass...... not bad for a bone stock motor on 9 lbs. i guess.
11-15-2009, 08:39 AM
#19
Hey almost a 10 thats pretty decent on stock engine.I assume you have a stall ,what tranny? Do you have a two step?
60ft not bad either if you didn't get any boost on launch.
Oh was thinking sure your inlet tubes are not sucking shut? And you are pretty sure your turbos are still ok..no excessive play when you check them. no big oil out the back?
Anyway good you go to have some fun at track , I have to wait till next spring to test out my car. I didnt' have things finished up in time to go to track or dyno this year. Heck would settle for a gtech time for now but the roads are cold and don't have any real drag tires to use.
60ft not bad either if you didn't get any boost on launch.
Oh was thinking sure your inlet tubes are not sucking shut? And you are pretty sure your turbos are still ok..no excessive play when you check them. no big oil out the back?
Anyway good you go to have some fun at track , I have to wait till next spring to test out my car. I didnt' have things finished up in time to go to track or dyno this year. Heck would settle for a gtech time for now but the roads are cold and don't have any real drag tires to use.
11-15-2009, 12:58 PM
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i am running a Vig. 3000 stall and TH400 trans........ no 2 step so i start to push through the brakes at 2400 to 2500 rpm ...... i f i could have built at least 3 to 4 lbs on launch....... that would have been a 10 second pass..... was going to ad a 50 shot of nitrous for 3rd gear on the big end but i am already out of gear..... going through the traps at 6000 rpm with 3.42 gears.
