New Turbo Now Installed...

[dbo]

I got an RB20 with a GT25R, so I know about lag aswell...

you say it kicks in bout 3500 and full boost bout 5000.. sounds very similar to my car. I'm not sure you have done anything wrong, it may just be down to the fact that the turbine is abit small for the compressor to be responsive.

I bought a SII RB25 turbo to put onto my car, as I'd prefer abit less power with more response (i'm into drifting, so it makes sense to have more usable power..

Although in saying all this, The GT25R I have would be a ripper turbo for a drag GTS-t or even better on an RB25. The turbo you have will probably make buttloads of power aswell, although only in the top end.

[kwazza11]

i'd say youve got a exhaust leak either on the manifold to head gasket or turbo to manifold, recheck all the bolt tensions.

Edited May 8, 2006 by kwazza11

[CATKICKER]

Thanks for the input dude, I did check whe I hooked it up but may be something to look at (plus I can get to it while it is in there). I am also going to check for boost leaks because I have a feeling that may have something to do with it...

Cheers,

Todd

Check the actuator is not the problem, being too long and holding the wastegate open.

Did you check that before you put the turbo on? I had a GCG on my 2.5 and it was as laggy as you describe, turned out the wastegate was being held open. Fixed that up, now nice and responsive.

[Guest Mashrock]

lag is fun anyway.

[CATKICKER]

lag is fun anyway.

Not as fun as a responsive turbo!

I hate not being able to stab it in third and get thrown back!!

I hate not being able to put my foot down in second coming out of a corner and get the back end out!!!

I hate lag!!!!

Unless there is something wrong that I can fix, its coming out!

[CATKICKER]

BTW: the turbo has a fast ticking noise down low (even when revving while stationary) and then once it hits boost, it has a real high pitched whur/scream - almost sounds electronic)

I am just putting this down to larger wheels, larger turbo... Any suggestions?

I am going to take it to some mates that know their stuff and see what they think...

Edited May 8, 2006 by CATKICKER

[CATKICKER]

will check tomorrow night... I have a feeling I might have been too careful not to snap a bolt off!

[sky30]

BTW: the turbo has a fast ticking noise down low (even when revving while stationary) and then once it hits boost, it has a real high pitched whur/scream - almost sounds electronic)

I am just putting this down to larger wheels, larger turbo... Any suggestions?

I am going to take it to some mates that know their stuff and see what they think...

Id say you turbo is worn out, that screaming noise when it comes on boost ids most probably the compressor wheel rubbing against the comp cover (not good).

I d check it out for shaft play.

[CATKICKER]

I don't think it is but I will have it checked... Shaft play was pretty much not there and less than my stock turbo and that was perfect.

[mr_rbman]

i'd say i told u so but u said not to, oh well, maybe get it tuned and they might be able to improve on it.

[CATKICKER]

Have just had another look at it tonight.

The wastegate is definatly closing all the way (I can hear in when I pull the actuator arm manually).

When revving it in the garage, the ticking sound (only way I can think to describe it, kinda sounds like a big 308 - almost sounds like it is running rough, but it isn't).

I am pretty sure it is going to be the gasket between the manifold and the turbo leaking somehow as that is where the sound seems to be coming from (stuck a bit of tube to my ear and then around the turbo area to get a presise area where it was)... I tried to tighten it but really wasn't able to get any more out of the bolts.

I think I will run it past one of the performance mechanics down here and see what they think! Not looking forward to having to take it off again but will have no choice if that is the case. Might take it out and sell it to get something a little less laggy.

Can anyone tell me what the symtoms of a leaking turbo gasket are? sound I am guessing but what else? Will I be losing responce / power? Cough a little when streching out?

Thanks for all the suggestions and comments guys, it all helps and is much appreciated!

Todd

Edited May 9, 2006 by CATKICKER

[AlexCim]

my issue will have the following symptoms

- semi silent turbo on idle

- on slight slight throttle, there will be a rattle in the dump pipe/turbo area

- once 0psi+ is reached, the rattle (its like, small bearings in a can being rattled) goes away.

The noises you describe sound like a manifold to turbo gasket leak..... you did change it right when you changed the turbo??

[CATKICKER]

I didn't change it because it looked fine... didn't even goop it when I had it right there... I am a silly boy!

[R31Nismoid]

I think your paying the price of buying something without knowing the specs.

You can see that the turbine housing has been milled out a silly amount to fit that exhaust wheel in there.

I wouldnt be surprised if it came off an RB30

[CATKICKER]

I believe it came off an RB25 and was then hiflowed... Yeah, I noticed that the exhaust wheel was pretty friggin big!! Can't believe they fit it in!

Will be nice to see how it goes if it indeed is the gasket.

I will get a pro opinion and update.

Is there a best place to get the gasket? How much should I expect to pay? (Standard t3 I am guessing?)

[Ceffy_SA]

Hmmm, the turbo looks a little like my one i have waiting to go on my RB20. Reading your restults of your new turbo have got me worried about my new one, i really want to avoid too much lag as my car is a daily driver.

Here are some pics of my "hybrid" turbo, its a HT18 front off a RX7 series 4/5 with a rb20 rear housing on the back and the RX7 steel wheel that has been machined into the rear housing. Most people here would agree my turbo would probably have the same response as yours catkicker. Ill might sell mine now, anyone want a fresh'ly rebuilt turbo i couldnt handle full boost by 5000rpm

Edited May 10, 2006 by Ceffy_SA

[CATKICKER]

Obviously I don't know that much about turbos however the compressor housing is a lot smaller... still could be laggy though. I am getting used to mine now and have booked it in for a checkup tomorrow to find the problem (have been told it sounds like the gasket as expected!)

Not any good for drifting or stop and start but top end power is huge! Probably give it a bit just for the love and see if I get sick of it...

[Rolls]

Rotaries tend to have pretty big rear wheels so at a guess Id say its going to be fairly laggy. Im not sure how it works with putting a bigger wheel into a smaller housing, if this affects it at all.

[CATKICKER]

Well... I took it to the mechanics today and had then run their eye over it. They told me that the turbo was too big for the car (as I already knew) and that there was a leak between the manifold and the turbo.

Ah hah... there we go!

soooo, I got pissed off with it on the way home so decided to cut a little sik!

I pulled it apart again and unbolted the turbo from the manifold (2hrs). I then found that the bottem left had pooed itself and there was nothing there, so I grabbed my gasket silicone and dropped it like it was hot!

Result, well at this stage I do not have anything to go on other than driving it from the garage to the cold outside (because I wanted to let the goop cure) however there was no leaking.

I will take it to work tomorrow and give it some stick on the way home and update... Fingers crossed!!

[Ceffy_SA]

Well... I took it to the mechanics today and had then run their eye over it. They told me that the turbo was too big for the car (as I already knew) and that there was a leak between the manifold and the turbo.

Ah hah... there we go!

soooo, I got pissed off with it on the way home so decided to cut a little sik!

I pulled it apart again and unbolted the turbo from the manifold (2hrs). I then found that the bottem left had pooed itself and there was nothing there, so I grabbed my gasket silicone and dropped it like it was hot!

Result, well at this stage I do not have anything to go on other than driving it from the garage to the cold outside (because I wanted to let the goop cure) however there was no leaking.

I will take it to work tomorrow and give it some stick on the way home and update... Fingers crossed!!

Will be good to see how it goes now, hopefully you will have reduced turbo lag