ok here I will explain my problem!! I've an ecotec 2005 in a cavalier 1999, I've a custom turbocharge setup... now I'm tired of having boosting problem i'm asking here!! I tryed everything I've no idea what is the problem.. Ok my problem is, when I floor the gas pedal my boost comme high(12psi) and after that come very low (5-6psi), ok now everybody told me, you have a piping leak blablabla....no my piping have zero leak, I do the leak test a lot of time, no leaks...after that i installed today an external wastegate with an external dump pipe, the boost come to 10psi and drop to 6-7psi...i'm really tired.... is it possible my turbo is too smal for my engine?? i use a garret T25 (eagle talon 99 stock turbo) I really have no idea what can cause boost loss like that
please help me!!
i will list here all my turbo setup for everybody know about everything to make sure they can help me correctly:
- Garret T25 (eagle talon 99 stock turbo)
- Turbonetic BOV
- Turbosmart external wastegate
- External wastegate dump pipe
- 2¼ Inch exhaust line
- No catalytic converter
- Cherry bomb exhaust
- SDS EIC with 2 390cc injectors
- 2inch custom piping going from the turbo to the intercooler and comming into TB
- K&N filter
- Custom turbo manifold (log style)
- Ngk Tr7 plugs
I think that is all...
please help me
http://cavalierdomination.monchar.com
Shifted wrote:2 1/4" exhaust is pretty tiny, that could be part of the problem.
i have an external wastegate dump, you think my exhaust could be a problem... dawmn
http://cavalierdomination.monchar.com
maybe the 2 1/4 is too restrictive and not letting the turbo spool freely.....maybe there is a restiction on the exhust side holding up the turbo....its a theory...not to sure though...
2 1/4 is capable of handling 300+ hp and over 20psi so i doubt it you exhaust i have seen 25+ psi ran on 2 1/4 with a catalytic converter and no problems.. it almost seems like the turbo is overspooling..
I have the same problem with my 2001 2.4L turbo but I got a cracked manifold so maybe you should check for leaks before the turbo.
The boost kick up to 8 psi but then goes down to 4 psi with high rev.
I have a 2.5 exhaust.
I will have it weld and i'll hope that the boost will stay at 8 psi.
DaveTres wrote:I have the same problem with my 2001 2.4L turbo but I got a cracked manifold so maybe you should check for leaks before the turbo.
The boost kick up to 8 psi but then goes down to 4 psi with high rev.
I have a 2.5 exhaust.
I will have it weld and i'll hope that the boost will stay at 8 psi.
euhm sorry for you but I dont think it is your problem, I also have my manifold breaking few time before I get it correctly fixed and this only cause for me the turbo spooling very slow, I wish for you it is your problem, for myself my manifold was checked yesterday, no crack no leaks....
http://cavalierdomination.monchar.com
justinhc wrote:2 1/4 is capable of handling 300+ hp and over 20psi so i doubt it you exhaust i have seen 25+ psi ran on 2 1/4 with a catalytic converter and no problems.. it almost seems like the turbo is overspooling..
when you say overspooling you mean my turbo could be too small for my car???? If i'm sure this is the problem I will upgrade for a giant one!!!
http://cavalierdomination.monchar.com
the t25 is a pretty small turbo, did you check the compressor map to see if it would even be efficient on your engine?And i dont think its your exhaust, i have 21/4 and can run 20psi just fine.
ya you should find the compressor map and see if the turbo is too small.. it is very possible that you just spinning it past its capabilities. dont go too big though.. i have a mitsu 20g and it works wonderfully
the turbo is to small, i can tell you that right now, you should have never wasted your time with it..just get another turbo
Volumeking333(Ryan) wrote:the turbo is to small, i can tell you that right now, you should have never wasted your time with it..just get another turbo
ok so i'm gonna check out for a new turbo!!
http://cavalierdomination.monchar.com
ok so I posted this yesterday and it must have timed out...
Where do you have your wastegate line comming from???
is it comming from the turbo or the tb...
I was having a huge problem with this. Mine would spike to 9 psi then drop all the way down to like 3 or 4 pis...
I was hooked up to the line on the turbo... when I moved it to my tb it was fine because then the wastegate was reading the boost pressure drop through all my piping.
if this helps cool if it does not sorry
horsepower is how hard you hit the wall, Torque is how far you push the wall with you
ya those stock dms turbos are so dam small for our engines. Arent those turbos only good for like 250hp?
Josh Csepegi (CUYOTE) wrote:ok so I posted this yesterday and it must have timed out...
Where do you have your wastegate line comming from???
is it comming from the turbo or the tb...
I was having a huge problem with this. Mine would spike to 9 psi then drop all the way down to like 3 or 4 pis...
I was hooked up to the line on the turbo... when I moved it to my tb it was fine because then the wastegate was reading the boost pressure drop through all my piping.
if this helps cool if it does not sorry
damn !!your right dude !! that was the problem!!!! I try it and now my boost is always stable
!!!! hurray for you josh!!! thx for your help!!! I also buy a new turbo !!! I'm really impatien to receive it and install it!!!!
http://cavalierdomination.monchar.com
Myles wrote:ya those stock dms turbos are so dam small for our engines. Arent those turbos only good for like 250hp?
Depends. Even a 14B - at least on our VR4s, can get 14 or 15psi without surging, and yeah, around 250HP if everything else is done right. But at that point they're pretty much maxed out and asking much more is risking it. And keep in mind the 2nd Gen DSMs actually used smaller turbos than the 1st Gen. If you want to use a factory Mitsubishi turbo, stick with 1st Gen DSMs and early EVOs. We just had an EVO I here last month for the VR4 meet that's laying down somewhere around 380HP on the stock Big 16G and there's a lot left in it. If I remember right, particular turbo will flow in the neighborhood of 500cfm and for our engines that should be plenty. So many people go on the parent engine's displacement alone to decide if the turbo is big enough, but I'd be willing to bet that a 4G63, though smaller in displacement, is moving just as much - if not more - air than an LD9 or maybe even an Ecotec. There's nothing wrong with using the turbo from another car, hell I'm doing it too, but if you don't know if it'll work, you really need to look at the compressor map, flow rates, etc.
wow I helped huh who would have thunk it... 4 years up working on this damn turbo car wrenching on it every day really gave me some info...
haha anyways man thanks for the props. and your welcome for the help.. anytime i can be of service man i will...
you too ln2johnny any time you want just send me an e-mail
horsepower is how hard you hit the wall, Torque is how far you push the wall with you
