Car running slow and theory to bounce off you guys.

[AL92]

I have a new 50 trim turbo on my car.AGP RS49.Its been slow to spool and not putting out like I think it should although have been running it at like 13psi as dont' have a fmic yet.
I do have fuel supporting mods.

Anyway I thought possibly a blown headgasket as see some white smoke but upon closer inspection white smoke is just condensation due to colder weather. Anyway when installed the new turbo the welded on elbow pointing to passenger side forced me and this could be because I didn't clock the turbo ,anyway the lower intercooler hose was serioulsy twisted to the point of being pinched almost totally shut.
I also did a boost test today and at about 20psi the tester blew off the turbo no matter how tight I tightened it on.This makes me thing that the air is not getting to the engine like it should.I know a boost leak will seriously take away power but would a boost restriction like an almost totally shut off line lower intercooler hose cause a massive power loss and make the spool very slow also.

 

[CanadianTSi]

Could be a boost leak, could be an exhaust leak, the IC piping deffinitly isn't helping...also 13psi on a 50 trim isn't going to feel all that fast...Remember supporting mods first people

When does it actually start to spool at?

 

[hostile]

You need to fix what you can and then go from there.

If you know something isn't right just make it right.

I also 13 psi on a 50 trim isn't going to feel like much.

 

[AL92]

I think its not really spooling up till 4000 and read it should be all in by then latest.
I know need some supporting stuff.Only thing left is the fmic.Fuel and tuning is taken care of.Have 2600 clutch to install also. I realize 13 psi isn't that much but seriously the car should go way faster than 16.1 at 90mph and best 60ft do to lack of power in first is like 2.50. I ran a 14.4 at 100mph with my 14b and 2.24 60ft on wet pavement.

Unless these 50 trims are super super laggy dogs and only work well at 25psi and 5000 rpm launches.If thats the case then likely go to an evo 16 and sell off this 50trim.

 

[AL92]

Replaced pinched off lower intercooler hose and car seems to run better.I am starting to turn up the boost and see how it feels.But pretty sure its faster than before but the old butt meter has bee wrong before.Will make some new tazzo runs and see whats up.

 

[AL92]

Ok this is embarrassing but have to tell the tale so others may not make this retarded mistake.After searching thru the forum looking for people with similar super slow boost problems like mine and after the car really not being faster today after fixing the pinched intercooler hose I found out what I did wrong.My AGP wastegate was not attached to the turbo.I just threw it on the 02 housing with rod attached facing the passenger side..DUH>
I had the wastegate wide open and guess when it finally build up some boost like 10psi by 6000 it would close it a bit mabye but of course everything was all backwards.Too tired and late tonite and didn't have my old 14 b to remember that the gate has to push the wastegate open towards the drivers side.I saw pic on this subject in the forum by accident and also in my haynes manual.
Wow I feel dumb but hey some instructions would be nice ok AGP guys!! I also didn't know could clock my turbo and chopped up my stock fan pretty bad.Betting didn't have to do that if clocked the turbo.Anyway think email agp with a few tips and putting up a nice install section on their site might be a good thing and also think they should sell the right head bolt as when I put my turbo oil feed off my oil filter housing had a heck of time finding proper bolt to block oil feed on head and finally wound up cutting a bolt to fit.

Anyway guys..I think by tommorrow I will have a rocketship.!! no wonder best time I could get with my 50 trim with gate and acutator backwards was 15.3 at 90mph..amazing it even did that.

 

[sweet97]

The actuator for an AGP does go on the 02 housing. You need to adjust the part that threads on so you have to pull it an 1/8" or so to reach the flapper pin which should be towards the 02 housing also. That is closed, with the flapper towards the 02. Mark

 

[repoofrs]

I've been having the same problems as him with the same turbo and I have a FMIC. I do have a small boost leak and now my exhaust is leaking, before the turbo I think, but prior to this, my turbo wouldn't really spool until I hit about 5.5K. Now, I suspect it is a wastegate malfunction maybe. How long should the rod be? Should I turn it all the way in so as to shorten the rod length and then try and attach it to the flapper? I am really at a loss as to what is causing my loss of power.

 

[sweet97]

Shorten the rod so that you will have to pull it about 1/8th inch to go onto the flapper rod. Too short and it will not boost till 25 PSI. Too long and you are running with the flapper open. You should start boost around 3500 and have 15 PSI by 4000 RPM. Mark

 

[repoofrs]

Cool, thats just what I thought. However, I have the rod shortened almost all the way and I still can not build any boost until higher RPM's. Most likely due to exhaust leaks but it was like this before as well, just not as bad.

 

[sweet97]

I just looked at mine and I have over 1/2" of threads still showin. Gotta fix those leaks! mark

 

[AL92]

I don't know about you other guys.Sweet 97 seems to be working ok from the sounds of it and doubt my turbo is fubar they are pretty simple and it does spool up no oil smoke etc.
I did have my wastegate closed not sure about the 1/8 past or whatever thing.So it seems that my problem is due to the exhuast pre turbo lots of people are now saying to me that it does cause big power loss and very slow spool.I may have some boost leaks too but not sure why but my tester was blowing off at like 15psi so hard to test things and tightened it like crazy too.Not sure if my pinched off lower intercooler problem had anything to do with that.Also do you have to check boost leaks with throttle open too or throttle closed.

Anyway my new thick supposedly unblowable gasket should arrive overnight express tommorrow and with luck will get it in there and go for a new test drive.I can't see my 50 trim being this slow spooling and gutless and having no low end as being normal.I have talked to many guys and read posts with similar turbos and while they said there is a bit of lag depending on rpm they also said the turbos are animals and fine on the street.But I swear if can't get mine working decently its going to be gone and a evo big 16 or ball bearing turbo will be in its place.

Anyway the only pre turbo leaks I have are my turbo to exhuast man gasket.I used the ring and pretty sure not supposed to.Also I have brand new evo ex man and brand new mits multilayer exh man gasket.I hope they are reusable as may have to take off my ex man to fix up this turbo gasket and clock the turbo a bit as its too close to my fan.I wish someone would have told me you could clock a turbo and included some tips and instructions.

 

[ninety7gst]

also 13psi on a 50 trim isn't going to feel all that fast...Remember supporting mods first people

why does it not feel like it's boosting until 15psi or more? my t25 felt powerful when u first started boost...i have a 50 trim now also

 

[sweet97]

That turbo is not starting to make power until 15 psi and really starts to kick at 18 PSI with some guys running 20 PSI or a couple more on pump. Is your mod list up to date? I'll look see! mark
How are you controlling the ful and what IC do you have?

 

[ninety7gst]

That turbo is not starting to make power until 15 psi and really starts to kick at 18 PSI with some guys running 20 PSI or a couple more on pump. Is your mod list up to date? I'll look see! mark
How are you controlling the ful and what IC do you have?

i have 650cc injectors and a walbro 255 fuel pump, controlled by ecu+ piggyback ecu (kinda like dsmlink) and the stock sidemount IC would that matter on low boost?

but that makes no sense to me....if it doesn't start make any power until 15psi...and i only have boost set for example 20psi, then is that 5psi of boost? if thats true, then it makes no sense to run a 50 trim turbo, cuz a t25 would be pushing 10psi....so wut do u mean by it really doesn't make any power until 15psi?

 

[sweet97]

Your stock turbo had a sweet spot so to speak from what 8 to 16 PSI? The 50 trim is making more at 15 than the t-25 was at 15 because it is puming denser air, it is more efficient. Once the 50 trimgets to it's power range of 18-22 PSI and you shift and keep the rpm's up you will feel more power. What's the "piggy-back" you have? I use a MAF-Translator for fuel control. You will be needing an IC upgrade if you have a stock IC. I just got my 50 trim so it is tuned for 17/18 PSI and it's much bettet than the 14/15 I had before and I am expecting to reach 20 PSI. It's a different feel. My EVO III was a terror with quick boost. I don't know yet if I will get the 50 trim to that same feel since it does spool slower & make power at a higher RPM. Mark
You are making more power at 15 PSI with the 50 trim but taking longer to get there and rpm's need to be kept up to getthe 50 trm to work the way you want.

 

[ninety7gst]

wow that's insane, i didn't know turbos had a "power range" i figured that was just engines...
well it almost FEELS like i get as much boost when the 50 trim gets 15psi
as my t25 felt like when it started boost....maybe this is because im at a higher speed and it takes more to push you in your seat at higher speeds? also i have an internal wastegate w/ a mechanical manual boost controller if that matters

a couple more questions....
#1 - if you were only running 10psi a t25 is better than a 50 trim?
#2 - wouldn't a bigger turbo push MORE air in than a smaller turbo @ the same boost?(even low 5-10psi boost) if so y doesn't it feel like it?

 

[sweet97]

Yes turbo's have a "range" where they are most efficient. I may have given some confusing info. At 10 psi the t-25 is probably making more power than the 50 trim. Maybe not. This is not easy for me to answer.The 50 trim makes power at a higher engine RPM. The way you "FEEL" it is te confusing issue and again the 50 trim likes to be in the 18-22 psi range for most power. The T-25 is down lower, more like you probably drive every day. There is a pst about a guy wanting to run a Holset 35 which will not start to boost until 4000 RPM.
You need to get the 50 to run at 20 psi with good tuning & get used to keeping the revs up. mark

 

[Mirage2LTurbo]

Soooo much mis-information.

-Colin

 

[sweet97]

Colin how about a little help?! I admitted I could not explain the "phenomonom" of the "feeling" he is getting between the 2 turbo's at 10PSI. I admit my lack of knowledge though I have experienced some of what is going on between turbo sizes. So how about some help?
Thanks, Mark

 

[ninety7gst]

my boost is set @ 22psi on pump gas

 

[Tongboy]

Yes turbo's have a "range" where they are most efficient. I may have given some confusing info. At 10 psi the t-25 is probably making more power than the 50 trim. Maybe not. This is not easy for me to answer.The 50 trim makes power at a higher engine RPM. The way you "FEEL" it is te confusing issue and again the 50 trim likes to be in the 18-22 psi range for most power. The T-25 is down lower, more like you probably drive every day. There is a pst about a guy wanting to run a Holset 35 which will not start to boost until 4000 RPM.
You need to get the 50 to run at 20 psi with good tuning & get used to keeping the revs up. mark

lets straighten this out a bit.

a range where the turbo is efficient is its efficiency range and it has to do with pressure vs air flow not just straight pressure. it is only related to engine speed when looking at when the engine is pumping enough air to get it into its effeciency islands. a turbo that will flow more air at the same psi as a smaller one will take longer to make more psi becuase its flowing more volume then the smaller one.

 

[sweet97]

my boost is set @ 22psi on pump gas

Well what's it like at that boost? I hope much better because that is my goal!

 

[ninety7gst]

well it really feels like 13 or so psi on a t25 when ur in 2nd and finalyl grab traction ...but i am at a higher moving speed...like mph wise than when my t25 was boosting....at higher speeds i can feel the difference, cuz u couldn't really feel the t25 push u in the seat when i'm in 3rd


but im still confused on the whole smaller/bigger turbo thing....i know u need higer rpms for a bigger turbo to make it spool up, but 10psi should feel like 10psi.....regardless how big the turbo...just like 500hp should feel like 500hp no matter the engine or car... plzzzz clear this up for me...im so confused...

 

[AL92]

10psi don't feel like 10psi on different turbos.Its not the boost pressure its the airflow that makes the power difference.The bigger the turbos the more air they move thru and the more power you get.
Now upping the boost on the same turbo will make more power up to the point where the turbo starts pushing too hot air and efficiency gets way too low.

So there is no way in heck a 14b or t 28 feels the same at 10psi as a 50 trim at 10psi.Or at 20psi or 30psi.

The turbos are rated in airflow to give rough ideas of how much hp they can support.
For example my AGP RS49 is rated 49 lb/min. A 14b is way less.So it can't support anywhere near the power of a 50 trim.Even if you up the boost on the smaller turbo you reach the point where the additional boost doesn't increase power and you are pushing the little turbo too hard.

Efficiency maps I guess come in to this discussion too but I think the 50 trims are actually efficient even at 10 or so but they just aren't moving that much airflow at 10psi to really be impressive yet.

Anyway it all theory crap and basically the bigger turbos put out more power at higher boost levels but the downside is usually slower spool.You can compensate a bit by downshifting but of course this dont work when going up thru the gears.This is why you would lauch higher on a bigger turbo and try to keep the revs up also.

I also am not that impressed running my 50 trim at around 10 psi or so.But betting it is putting out close to the same power as my 14b was at 15 or more.I like sweet 97 have
big hopes that the 50 trim will turn into an animal when i can run 20 to 22 on the street.I need to buy a good front mount intercooler and install my new water /alco injection system.But I am fairly confident that 50 trim can do me proud once running up in that 20 range.