Think i screwed up - Boost Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Think i screwed up
Sunday, September 24, 2006 4:16 PM
Well i've had the car out for about 2 months now. Runs ok... considering its untuned at the moment. I finally had a car decide to go me lastnight from a roll in 3rd gear. it was none other than a 5.0L stang. car kept up with him no problem and i wasn't even redlining it (7.5psi). the problem is this however. i can almost never get it up to the lbs of boost it should be at when i stomp in it. i think i screwed up on the trim and a/r on the turbo that i got. its a super T70. trim is 64.5 with a turbine a/r of .84 and a compressor a/r of .70. is this turbo a little to big for the car, or is just the fact that it hasn;t been tuned yet? for the spring its getting bigger injector, inline fuel pump, fuel rail, clutch and flywheel as well as either a piggy back system or standalone (which i can afford)

Re: Think i screwed up
Sunday, September 24, 2006 4:38 PM
double check everything for boost leak.... the turbo is a bit on the big side but u should still be able to get something out of it. I would make sure everything is hooked up right and nothing is leaking to cause it not to boost.



Re: Think i screwed up
Sunday, September 24, 2006 4:40 PM
Holy @!#$ that's a huge turbo...





4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!

Re: Think i screwed up
Sunday, September 24, 2006 4:44 PM
hahaha yes, yes it is. i had to put it inside the egnine bay in two peices cause not matter what way i tried, it wouldn't fit. think i might have to drop down a size. but i still want the T3/T4. have any suggests then? i'm looking at making 400whp+ when i'm all done.
Re: Think i screwed up
Sunday, September 24, 2006 4:49 PM
I had a t3/t4 57 trim .48/.60 on my 2200 and it did what ur talking about. It was so hard to tune. However, i switched out to my t3s60 I have now and my A/F's have since come out ALOT better. Too much air, not enough fuel is BAD. Also, that turbo you have pushes alot of air, meaning you're needing even more fuel to even things out. From my old turbo to my new one, I didnt even need to change injectors or pressures, etc to get a consistant 12.0-1 A/F on my wideband throughout my powerband. IDK, just my personal exp.








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 4:54 PM
i should have mentioned before when i posted this, i have the 2.4 LD9 motor (1999). i was wondering if i should switch over to the garrett super 60 turbo
Re: Think i screwed up
Sunday, September 24, 2006 4:56 PM
A t3/t4 50/57/60 trim would be nice, depending on motor specs. Also, a .63 ar on the turbine would be a good idea, .48 would end up being start to get restrictive around the 300-350 whp mark. To hit those #'s, you'd definitely be building that motor up so I'd go with a 57 or 60 trim w/ .63/.60 ar's.








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 5:00 PM
oh for sure. the motor will be built. those a/r's are you talking compressor side or turbine side? the motor won't be built for awhile though. so i still need to to spool fast and hard. and pull hard right up to redline
Re: Think i screwed up
Sunday, September 24, 2006 5:04 PM
A t3s60 maxes out around 300-325 hp, so if you're serious about hitting 400+, ur gunna need to stay w/ a t3/t4. Also, do you even have ANY fuel mods? FMU, injectors, pump? If not, your gunna pop ur motor quick. At the minimum i'd say you need at least an FMU and 330cc injectors for the psi ur on. Im not too fimiliar with boosting an ld9, but I think the stock injectors are around 250cc. I got some 370cc RC engineering injectors(hi-imp) if ur interested. I'll let em go at a good price, paid around 300 for em. Shoot me an email(in my reg) if you want em.








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 5:10 PM
Turbine=.63 compressor=.60. There are many dif sizes available like turbines of .48/.63/.84(?) and comps of .50/.60 If your looking at a turbo thats good now and after, hit a t3/t4 .63/.60 w/ 57 trim(or 60). it'll spool around 3500 or so now, and (depending on the build specs) around 3000 when built. Like I said ,depending on motor specs, It can spool earlier OR later, but you bump ur redline up also with valvetrain and tuning tools like HPtuners. Possiblities can be endless, if the money's right








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 5:16 PM
so the one i have now could do the same with proper tuning than correct? or do you feel its just a little on the big side?

Re: Think i screwed up
Sunday, September 24, 2006 5:23 PM
I bet it'd be okay with proper fuel mods, after the build up the powerband will be alot better. When does your's spool? IIRC, that turbo is capable of 400+ whp EASY! You can stick with it for now, but I highly doubt your in the turbo's efficiency range. That means it's prolly getting heat soaked which isn't good on your seals and bearings.








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 5:36 PM
ya the turbo is capable of 500+hp. it spools at 3000rpms which is where i want it. just takes a bit of time to hit that 5=psi mark. but i'm thinking its because its not tuned yet. when i get the head port and polished, stronger vavle springs and 5 angle valve job, it will flow air alot faster and i can hit those higher rpms. would love to get it to hit a redline of 8-9000rpms
Re: Think i screwed up
Sunday, September 24, 2006 5:45 PM
oh and explain what heat soaked exactly is. cause there has to be a way around that? i think i'm gonna be wrapping the downpipe in exhaust wrap and getting an insulator for the turbine side of the turbo, cause its getting warm under the hood.
Re: Think i screwed up
Sunday, September 24, 2006 5:47 PM
Get the fuel setup first, then go from there. You want to build the motor, not get another you HAVE to build! Also, if you're spooling at 3K but not full boost within 500 rpms after spool, i'd say you got some boost leaks. If the car is running really lean, then yes it might not hit full boost cuz the engine is cutting out. As the rpms climb and the boost is going up, if the fuel isn't coming in with the air accordingly, then the injectors are going to lean and clip out, not letting you hit the 5 psi or whatever. it's like the air is starting to pressurize and then it loses pressure do to being lean, causing the exhaust gases leaving the combustion chamber to lose pressure and not spin the turbine wheel hard enough to produce the boost you are trying to hit. I hope that makes since!








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 5:52 PM
and the heat soak? will the exhaust wrap and turbine insulator help?
Re: Think i screwed up
Sunday, September 24, 2006 6:24 PM
The heat soak im referring to is that the turbo is running efficiently. IT's not spinning at the rpm's/boost level it needs so in turn it's causing more friction on the turbo's shaft/seals/bearings. That causes them to overheat and heat soak. You need to find the compressor map of your turbo to find out it's efficiency range. On a turbo that big, it's lowest efficient boost level is probably around 10 psi or more.
Basically, you aren't turning the shaft fast enough to keep it cooled down. It sounds weird, I know, but it's true. Like when you use a drill bit that goes threw a piece of metal easily, it doesn't get as hot as if you use a bit that just sits there and spins. It gets really f'n hot! It's almost like the shaft going threw your bearings is moving to slowly, causing it to store heat, instead of rotating fast enough to expel the heat from it. The oil running threw the bearings can only cool it down so much.
All in all, not keeping a turbo in it's efficiency range will end up causing it to prematurely fail! Meaning, it'll need a rebuild MUCH sooner than expected!








Failure is not failure if you learn from it
Re: Think i screwed up
Sunday, September 24, 2006 8:57 PM
Shifted wrote:Holy @!#$ that's a huge turbo...




LE61T PTE6262 Powered

Re: Think i screwed up
Monday, September 25, 2006 1:32 PM
sounds like the turbo is too big, and the system is to inefficiant.......... to build proper boost. You need a smaller turbine a/r...... .84 is to large......... try some thing in the low to mid .60's.......

You can hardly hit 5psi by the time you hit redline?





SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

Re: Think i screwed up
Monday, September 25, 2006 2:41 PM
I can hit full boost if i redline it threw the gears. but if i stomp on it in say 3rd and take it to the red, it won't hit full boost. i'm moreless wondering if its because i don;t have it tuned yet

I have an FMU out of a ford probe V6 that was turbo'd. still need injectors and a new pump. just trying to figure out what size of injectors i should go with. i don;t want to have to keep changing them with increased boost. maybe 500cc ones??
Re: Think i screwed up
Monday, September 25, 2006 3:50 PM
to give you a straight answer of "is it beacuse its not tuned yet?" the answer is no.....the turbo is simply too big.

Re: Think i screwed up
Monday, September 25, 2006 3:56 PM
What exhaust size do you have? Could that be too restrictive?
anywho, sounds like a boost leak, nachotec had the same problem, he couldn't get past 8 pounds for the life of him.... rechecked and sealed all his boosting tubes, car went right to 15 lbs....that was an interesting ride. hehe
Re: Think i screwed up
Monday, September 25, 2006 5:56 PM
thats a freakin huge turbo man. Maybe a smaller turbine would help along with maybe a smaller compressor. I had a .50 compressor and a .63 turbine with 57 trim and it spooled to 8psi by 3k. On the eco motor by the way so little less flow and smaller displacement. Your turbo is to big for your build right now. Down size it and build it and you'll be in 350+ easy. Good luck.


*2012 mazdaspeed3*
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search