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Discussion Starter #1
I am running a Turbonetics 60mm ball bearing watercooled turbo with a manual boost controller. The boost increases with each gear 1st is 7psi, 2nd is 8.5, and third is 12psi. Is this normal or is something not installed correctly. Also would it be different with an electronic boost controller? I would like it to produce roughly the same psi in each gear. Any ideas???
 

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no one ever responds in this section it makes me mad! im one thread above u
 

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bueller
 

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I have a turbo but don't know much how car stuff works...my mechanic handles everything. I'll give my 2 cents but I wouldn't take it as a definitive answer. My car has an electronic boost controller and one plan is to launch the vehicle at the lowest boost 11 lbs, and then go to a higher boost level (maybe 16-18 lbs) in 2nd and max the boost in 3rd. The digital controller allows you to do this. I wasn't aware that a manual controller offered programed incremental boost level increases...so my best guess would be that this might NOT be normal. Maybe it has something to do with the amount of time available for spooling in each gear???

Don't have the race tune locked in yet, so none of the above is track tested.
 

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a big question here would be what kind of boost controller is it, If Its A ball and Spring then you can have weak or stong spring and its not giving it enought time to spool in each gear because it will go through the lower gears faster.

I've have not personally heard of staging the boost in each gear like that, but if an electronic boost controller is set up that way it should be fine. But in a perfect world you should want the same boost in each gear so its perdictable and you dont over boost.
 

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Discussion Starter #9
Well I think it is a combination of things. I removed the controller and I'm producing more boost in 1'st and 2'nd gears, (8#'s) but in 3'rd I'm reaching about 12.5 psi. This is with the 5# spring in the waste gate. And to top it all off my clutch is starting to slip with the extra power. I was hoping it would last a little while 'til I got things lined out. It only slips when I launch so if I take it easy in 1'st maybe it will hold out 'til then. The turbo does seem to stay spooled up now. I'm using the Turbonetics Evolution wastegate that came in the kit. Any ideas?
 

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ok the next thing it could be is restrictive exhaust, when you wastegate opens to allow the extra air bypass the turbine, it needs to flow enough air out so that it doesn't continue to build boost when its not supposed to. If its not that the waste gate could be bad (not as likely) .

But I got a good test for you. Get on the highway of high MPH road and cruise it 5th gear at low R's and give it some gas untill the boost reaches max. If its pulling over 12.5 you know its restricted exhaust. If it lock at 12.5 then see if you can get 1st and 2n'd to pull any more boost.

With just the Stock wastegate I'll bet you any thing your only supposed to make about 8.5 PSI and when you hit 3rd your exhaust it out flowing your pipes.

BTW when you do these tests keep the boot controller off.
 

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every forced induction car ive ever known of...factory or aftermarket does not make as much boost in lower gears except for pd blowers...my does this as well...its has to do with the time it takes to spool up and being in the lower gears it doesnt have enough time
 

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Discussion Starter #13
every forced induction car ive ever known of...factory or aftermarket does not make as much boost in lower gears except for pd blowers...my does this as well...its has to do with the time it takes to spool up and being in the lower gears it doesnt have enough time
So with the 5# spring it should produce 13psi in 4th gear???
 

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So with the 5# spring it should produce 13psi in 4th gear???
depends on your waste gate


and as far as the comment about building boost
if you have a good turbo and wastegate i dont see that at all
once i spike 8.7psi it STAYS in first, 2nd, 3rd 4th and 5th

garret SC44 JOURNAL bearing not ball bearing or anything special

i'll hit peak boost at the same psi level in EVERY gear
 

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Discussion Starter #15
depends on your waste gate


and as far as the comment about building boost
if you have a good turbo and wastegate i dont see that at all
once i spike 8.7psi it STAYS in first, 2nd, 3rd 4th and 5th

garret SC44 JOURNAL bearing not ball bearing or anything special

i'll hit peak boost at the same psi level in EVERY gear
Thanks! That is the way I thought it should be. I don't have any experience with FI, and I haven't found anyone locally to get any advice from. I don't do business with the speed shop that dyno'd the car anymore either (they ran 21psi of boost through my stock bottom end while dynoing). I don't think they were trying to blow it up...? Either way I don't put much faith in them anymore. Luckily the stock clutch let go @ 569 rwhp on a mustang dyno.
 

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wow i think i'd have to shoot somebody in the big toe for that (21 psi run)
 

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the turbo works with the exhaust. the more you work the motor the more boost you will get. that is why some turbo guys run 3.73 instead of 4.10's to build up boost quicker. it is normal don't worry. i don't get full boost until 3rd. I run a 76mm turbonetics w/ 4.10 gears.

you should not run more that 8-9psi with a stock lower block.

i hope this helps.
 
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