Gt2871r .64 Sr20det

[rotation3x]

Ok, So I went to get my car tuned and ended up with nothing. Here is my setup

Sr20det redtop stock internals
Gt2871 .64
Greddy Fmic
300zx mafs
740cc injectors
Full turbo back 3" exhaust (No Cat)
Apexi power fc


Everything bought brand new except mafs

I have a garrett 14lb wastegate actuator that I had bought separate from the turbo.

We get the car on the dyno and it is pushing 19+psi at 1/4 throttle at 38-4000k rpm. So the tuner says the actuator is to tight and was out of threads to take some tension off. He welded an extension to it. Still did the same thing.

After that he disconnected the actuator from the turbos wastgate flap and saftey tied it up/open. The turbo still made 19+ psi at 1/4 throttle at about 4k rpm. The boost read 3-4 psi all until 38-4000 rpm then it spiked and the tuner said it would have kept going if he didn't let off.

I know I have have no tuning skills but I put everything together myself. I do have some knowledge of it, but this is just kinda hard for me to explain because I nor anyone else has ever had this happen. So with that said PLEASE DON'T FLAME ME!

http://i260.photobucket.com/albums/ii15/nis240drft/jb021.jpg

http://i260.photobucket.com/albums/ii15/nis240drft/jb026.jpg

http://i260.photobucket.com/albums/ii15/nis240drft/jb027.jpg

http://i260.photobucket.com/albums/ii15/nis240drft/jb028.jpg

[SoguRacing]

I just put together my turbo..same as yours, can i get a better pic of the actuator rod? say..from the side? My turbo spools fine. i just need a tune and to install my z32 maf,injectors and some other stuff. get a better pic and maybe i can help you. Actually, it looks like your wastegate is open which would allow exhaust gases to exit the housing and not make boost. Try tightening / shortening the lever until its closed with tension on the lever. you should have to pull the bar out of the actuator which will take a bit of force and slide it on the flap and put the retainer clip on it.

[lazierhobo]

dont really know about your other problem, but you dont want your o2 sensor right at the top of the turbo elbow like that, it will get way too hot and you will kill it instantly. you want it to be further like 14-18 inches from the turbo.

have you gotten the wastegate to open at all? maybe the actuator is bad

[Sileighty_85]

I just put together my turbo..same as yours, can i get a better pic of the actuator rod? say..from the side? My turbo spools fine. i just need a tune and to install my z32 maf,injectors and some other stuff. get a better pic and maybe i can help you. Actually, it looks like your wastegate is open which would allow exhaust gases to exit the housing and not make boost. Try tightening / shortening the lever until its closed with tension on the lever. you should have to pull the bar out of the actuator which will take a bit of force and slide it on the flap and put the retainer clip on it.


hes trying to lower his boost not rasie it, he said he disconnected the Flapper and still hit 19PSI

I must say that is weird what boost gauge are you running? Maybe bad?

dont really know about your other problem, but you dont want your o2 sensor right at the top of the turbo elbow like that, it will get way too hot and you will kill it instantly. you want it to be further like 14-18 inches from the turbo.

have you gotten the wastegate to open at all? maybe the actuator is bad

Thats the stock location for the O2 Sensor

he just said he tied the WG flapper open and it still hit 19+ PSI

[SoguRacing]

My bad, I was thinking the opposite cuz i had the opposite problem recently of not getting any boost.

[chaseSR86]

has to be your gauge? whats the afr with 19psi?

[rotation3x]

has to be your gauge? whats the afr with 19psi?



My gauge is a brand new stri x line. The tuner was mainly going by his gauge on his laptop/dyno screen until I told him to check mine to see if it was reading the same and it was. afr was 10.5:1.

[rotation3x]

The reason the flap is open a little is because I had to drive the car home 2 hours without going over 1/4 throttle which would cause it to spike to 19+ lbs
So the tuner thought to leave it open like that just for saftey.

[slider2828]

Here is the easy stuff.... How is your vacuum hooked up? You said you disconnected the flapper from the actuator rod? Did you try this? Pictures please of you doing this.. You don't have a boost controller just an actuator?

[rotation3x]

Here is the easy stuff.... How is your vacuum hooked up? You said you disconnected the flapper from the actuator rod? Did you try this? Pictures please of you doing this.. You don't have a boost controller just an actuator?


Ok there are 3 nipples on the throttle body ...

top left going to fpr t'd off to boost gauge

top right going to nipple on hotpipe

Bottom nipple not used

The tuner disconnected the flapper from the actuator rod while on the dyno.

And there is no boost controller.

Sorry I didn't bring my camera to the dyno.

[rotation3x]

I just don't get it, people are saying I gotta bore the wastegate hole bigger or go external. I havn't seen anybody have problems with this turbo running the stock actuator.

[IStop4NoMan]

Ok there are 3 nipples on the throttle body ...

top left going to fpr t'd off to boost gauge

top right going to nipple on hotpipe

Bottom nipple not used

The tuner disconnected the flapper from the actuator rod while on the dyno.

And there is no boost controller.

Sorry I didn't bring my camera to the dyno.

wait you said the top right is going to nipple on hotpipe? i hope you mean the BOV. also, where are you getting your actuator vaccum source? that should be coming from either very close to the turbo on the hotpipe, or from the turbo itself. can you manually open the flapper with the actuator off?

[Prok0]

You may want to check and make sure the diapragm isnt ripped..

Take some vacuum line and put it to the wastegate nipple, then take a compressor and put a little air into the line ( Not a whole lot, dont want to tear the diapragm ) you can just hold a nozzle up to the line but not physically put it in, and the wastegate should push the actuator rod back, if it doesnt your diapragm is probably torn and air is probably bleeding out the back of the wastegate...

[SoSideways]

You might want to double check to make sure that the O2 housing isn't blocking the wastegate flapper on the turbine housing from opening.

I've had experience where I helped a friend put a Megan Racing O2 housing onto his T28, and he was getting crazy boost just like you said. Turns out the little piece that bolts onto the O2 housing that acts like the divider on the GReddy O2 housing was blocking the WG flapper on the turbine housing from opening.

If it isn't blocking your WG flapper, and the WG flapper is able to open 100% and you're still getting 19psi+ at a quarter throttle, then something else is wrong.

[rotation3x]

It has to be something else. I checked with my stock 02 outlet and my Ebay outlet that I was using and neither hit.

Actuator seems to be fine. I did the compressor thing it worked, however I set my compressor regulator to 14 ish psi and it didn't move it much so i put it at about 22 psi and it moved more....I did not feel any air coming past it.

Istop4noman : I did mean the bov haha sorry about that. Yes my wastgate vacuum source is on the nipple on the hotpipe about 6" from the turbo.

[SoguRacing]

does your internal flapper hang up on anything inside? does it have free motion?

[ROIDMONKEY]

R u using a boost controller? if yes check in the back of the BC it should have a little switch , that switch is when u running a external wastgate or internal .

[SoguRacing]

you might want to specify what brand boost controller you're talking about because i have an AVCR and it doesn't have a switch

[rotation3x]

I had a greddy profec b spec II and I think it may have had a switch but regardless I disconnected it anyways.

I talked to my sales person where I got the turbo from and he has been talking to precision for me and they are telling me to pull the exhaust housing off the turbo to see if a lip was left on the inside of the wastegate hole and to smooth it out if it was a lip and if not I will need to upgrade my turbo manifold

[rotation3x]

does your internal flapper hang up on anything inside? does it have free motion?


Yes the flapper opens freely with the actuator rod disconnected with both stock and my ebay outlet pipe.

[IStop4NoMan]

its gotta be the actuator, no doubt about it. is it adjustable? like the HKS type?

[McRussellPants]

Ign timing or cam timing is messed up?

we just dealt with an RB26 surging like hell because the tune was so off that it was getting 19lbs at like 3000rpm

[Flybert]

im with russel pants. timing is retarded or exhaust valves are open because cam timing is off.

[ROIDMONKEY]

you might want to specify what brand boost controller you're talking about because i have an AVCR and it doesn't have a switch
mine is BLITZ and i was having that problem . read ur manual , im just guessing u know, u might not have that setting . but BLITZ BC have a little switch behind for that , external or internal wastgate

[1cleanS13]

FYI there is no switch on the back of the Greddy profec B type S, I just checked on mine...

[Prok0]

Actuator seems to be fine. I did the compressor thing it worked, however I set my compressor regulator to 14 ish psi and it didn't move it much so i put it at about 22 psi and it moved more....I did not feel any air coming past it.


If its a 14psi wastegate it should open up fully even before 14psi.. If it didnt there would be serious spiking issues... So maybe its wastegate and some timing problems as well..

[rotation3x]

Ign timing or cam timing is messed up?

we just dealt with an RB26 surging like hell because the tune was so off that it was getting 19lbs at like 3000rpm

That makes the most sense to me so far, But the engine dosn't run like timing is off.

I am going to double check timing and compression this afternoon.


As for using my compressor to check the actuator, I don't think my compressors gauge is very accurate.

[fliprayzin240sx]

K if you're still spiking with the flapper wide open, not sure whats causing your engine to push way more exhaust flow than most, but one solution is for you to mill out the flapper hole. Basically mill it out to almost the size of the flapper itself (just enough so the flapper will still shut but with the hole as big as possible). That way, when the flapper is open, more air will go thru the flapper than the turbine...

[OBEEWON]

Ign timing or cam timing is messed up?

we just dealt with an RB26 surging like hell because the tune was so off that it was getting 19lbs at like 3000rpm


Thats a good thing though!

[rotation3x]

K if you're still spiking with the flapper wide open, not sure whats causing your engine to push way more exhaust flow than most, but one solution is for you to mill out the flapper hole. Basically mill it out to almost the size of the flapper itself (just enough so the flapper will still shut but with the hole as big as possible). That way, when the flapper is open, more air will go thru the flapper than the turbine...

What would I use to mill through cast?

[water]

I'm guessing this is an issue with your actuator and/or where its mounted.

You should use an actuator meant for lower boost anyway and let the boost controller control your boost. You'll get faster/better spool. This is b/c actuators gradually creep open (it is a spring, remember) as boost increases causing slower spool but w/ the boost controller intercepting the signal, the actuator spring won't see pressure until just before peak boost is realized.

[rotation3x]

I never thought of it like that, but it made 19 psi with the flapper open manually. I know my actuator is good I bought it brand new.

[GSXRJJordan]

I cant believe everyone missed this...

IT SOUNDS LIKE YOU DIDN'T HAVE THE ACTUATOR HOOKED UP TO A VACUUM/BOOST SOURCE.

It's the only explanation.

Edit: Good luck, sounds like horrible timing or some other engine-related (not turbo/wastegate) problem.

[rotation3x]

It has to be something else. I checked with my stock 02 outlet and my Ebay outlet that I was using and neither hit.

Actuator seems to be fine. I did the compressor thing it worked, however I set my compressor regulator to 14 ish psi and it didn't move it much so i put it at about 22 psi and it moved more....I did not feel any air coming past it.

Istop4noman : I did mean the bov haha sorry about that. Yes my wastgate vacuum source is on the nipple on the hotpipe about 6" from the turbo.

The actuator is getting vacuum source from nipple on hotpipe.

[tt99ol]

10.5:1 afr is part of your problem
and if ignition timing is off and it misfires too
then you have anti lag
which spools turbos how a jet engine works
by burning fuel with the turbine blades
get it leaned out a bit and see if the problem goes away
go into your power fc and set the injector values to 50%
this will run the car as if it were on stock injectors so you can see if thats the problem

[rotation3x]

Yeah, I have talked to a guy at xs engineering and he said...

too rich
Fuel pressure too high

the car does not misfire, however it did before I got my 1/4 throttle tune.

[rotation3x]

My pfc injector is set at 50% now and 22ms.

[McRussellPants]

Thats a good thing though!

yeah, until you know what compressor surge feels like.

[Ninjabread]

I'm having a similar issue with my t28.

I have hks 264 step 2 cams though. Even with the flapper wired right open, I was seeing 15-17 lbs of boost. Gonna fix my external gate setup and slap it back on... It never went over 10 lbs (10lb spring).

[rotation3x]

I checked my timing and it is to spec. Only thing I couldn't find is where the cam gears are suppose to be, the intake cam is at about 10 o'clock and the exhaust cam is about 1.

I really don't want to go external because I mean I spent $1100 on the turbo with the internal design and it should be working. I just don't know what gives.

[v-empire]

i read it kinda fast, but seems like you have over boost issue. your car hits a brick wall and detonates a little at 3.5-4 k rpm? the boost gauges just spikes up ?

new doesnt mean its good.
i ve seen many new actuators, fpr, etc that are bad.
check on that. if you changed your source of vacuum to hot pipe, you should have steady vacuum source.


check on that. go for easy stuff first. good luck, let us know.

[Sileighty_85]

I cant believe everyone missed this...

IT SOUNDS LIKE YOU DIDN'T HAVE THE ACTUATOR HOOKED UP TO A VACUUM/BOOST SOURCE.

It's the only explanation.

Edit: Good luck, sounds like horrible timing or some other engine-related (not turbo/wastegate) problem.

i read it kinda fast, but seems like you have over boost issue. your car hits a brick wall and detonates a little at 3.5-4 k rpm? the boost gauges just spikes up ?

new doesnt mean its good.
i ve seen many new actuators, fpr, etc that are bad.
check on that. if you changed your source of vacuum to hot pipe, you should have steady vacuum source.


check on that. go for easy stuff first. good luck, let us know.

He said he diconnected the the Acuator Rod from the W/G Flapper and tied it open and its still spiking
he also used the tunners Boost gauge

[rotation3x]

^ correct. Does anyone know what size the wastegate hole should be? A few peeps have told me to make that bigger first. I took the exhaust housing off the turbo and the wastegate hole is smooth, nice and round and the flapper opens freely. I would rather not go grinding the hole out for nothing. Also the flapper all the way up is in the way of getting to the top of the whole.

I noticed I had my ebc (greddy profec b spec 2) vacuum line that goes to the controller t'd between the actuator and the hotpipe. I don't remember doing that or if the tuner did it for his guage. I wouldn't think he would do that.

[rotation3x]

I just bored out my wastegate hole, I will let you guys know if it fixes the problem.

[fliprayzin240sx]

What would I use to mill through cast?

Dremel is your best friend. Take the turbo off and and pop the exhaust housing off. Its not that hard to take it off the turbo.....

[rotation3x]

^^ Yeah man I took it off last night bored it out with the dremel and everything seems to be A ok now.

After putting everything back together and starting the car I noticed I had a fuel hose on the rail busted. Not sure if it was like that before, I wouldn't think so though since I drove it 2 hours back home from the tuner and didn't smell anything.

[rotation3x]

It is now holding 10 lbs after boring the wastegate hole. I will be taking it back to the tuner this week sometime.

[rotation3x]

Made 300.4 whp and 277.19 tq.

Boost was @ 18 lbs

A/F was 11.5:1

Now I got a blown head gasket.

[djcobra]

ouch! a blown head gasket... I'm surprised that some of the guys on here didn't mention anything about upgrading the head gasket or warning the poor guy when boosting more than 14psi. Anyways looks like you have to replace the bloody thing now, and while your at it might as well upgrade the cams along with a thicker metal head gasket and please don't cheap out! I personally use the Apex'i and boosting 15psi daily, car puts out ~320whp on a GT28RS (disco), combined with a HKS 555cc injectors, HKS Step2 256/264 cams, HKS springs, and retainers... good luck.

Steve.

[rotation3x]

Thanks for the advice!! I am getting a cosmetic metal head gasket.... I hope thats a good one.

also getting a new intake manifold gasket and ARP head studs

As far as cams go, I would like to stick with stock for now. I know the BC 264cams are suppose to be sweet with the 2871 but I am iching to drive the car.

[((sr)) kelly]

what is your duty cycle at 19 psi? i bet its th guage

[fromxtor]

Thanks for the advice!! I am getting a cosmetic metal head gasket.... I hope thats a good one.

also getting a new intake manifold gasket and ARP head studs

As far as cams go, I would like to stick with stock for now. I know the BC 264cams are suppose to be sweet with the 2871 but I am iching to drive the car.

I would get a cosworth or some other brand, cometic is nothing but trouble.

[idahotuner]

you should test to see if it opens up. takea air compressor anda nozzle that is jsut for blowing air. and use it to blow air into the acuator to see if it opens.

[idahotuner]

well ignore my abouve comment. i didnt take the tiem to read the whole thread.

but deff go apexi for your head gasket. use copper spray-a-gasket. and do ARP headstuds. those area must when changing head gasket.

[fliprayzin240sx]

^^^ +1, Do it right and do it once. APexi HG, ARP studs are worthy investments. Id spend the money on those over cams if I have to pick between the 2. Same some money later down the road, get the cams and get the car re-tuned with it.

Beside, with the .64 trim, you honestly dont need some big cams. Heck, even step 1 HKS drop in cams will be more than enough for that turbo.

[s15specR]

You got pics of the turbo area ? I'd like to see how it all comes together, thanks.

[rotation3x]

Finally got it back together.
New rod bearings
New main bearings
polished crank
new cometic head gasket
arp head studs
black top head with multi angle valve job

Have 750 break-in miles on it so far.

Changed it up a bit while it was out too.

http://i260.photobucket.com/albums/ii15/nis240drft/s14011.jpg

[GSXRJJordan]

Good luck with that Cometic gasket - post up your results after the next dyno!

[rotation3x]

:-/ Yeah I hope it holds up. Only one way to find out though. I put 1k breakin miles on it last night changing oil to sythetic today and going to see what its got @ 10 psi.

[SoguRacing]

apexi ftw, but good luck

[jspaeth]

Looks really nice and clean.

Minus the SSQ, but hey, whatever floats your boat or finds your lost remote

[BiG MiKE86]

So whats the update? Dyno'd again?

[rotation3x]

F a cometic head gasket people warned me but damn. I got a leak some where its not bad unless I get into boost my temp spikes up then comes right back down when idleing. On the dyno before I got it retuned It made 305whp 277 torque @ 15 psi on a dyno jet.
After trying to get it retuned it busted the gasket, it was building up pressure popping the rad. cap up and pushing fluid in the coolant tank while under boost.... Does not do it at idle. Anyways what are the some good headgaskets and thickness for my setup and don't say cometic I learnes the hard way.

[BiG MiKE86]

Apex-i
Power Enterprise?

I am personally using a cosworth 1.1mm but if I had to do it again i'd shoot for the Apex-i - I hear nothing but good about those

[moses]

Shit now you got me worried. I have the same set-up boosting at 18 psi and now I am scared that I will blow my head gasket. How hard is that to change? Can you chance the head gasket and still heep the head all together without messing with timing?