Jump to content
SAU Community

Recommended Posts

ok,

I'm running a pair of Garrett GT 2860 - 7's in my GTR, and i'm getting full boost are 6k, which is way too high in the rev range.

I currently had a Gizzmo MSIbc installed, and I have tried a manual controller and its still lagging.

I fitted the factory boost control solenoid and it ran 8 psi @ 4k which is about right.

Anyone else had a problem with excess lag in a GTR? Or have any idea why its lagging so much?

Mate suggested that the wastegates are opening too early, if this is the case can I restrict them somehow?

Any suggestions welcome

-Michael-

Link to comment
https://www.sau.com.au/forums/topic/355457-car-way-too-laggy/
Share on other sites

I'm running a pair of Garrett GT 2860 - 7's in my GTR, and i'm getting full boost are 6k, which is way too high in the rev range.

I currently had a Gizzmo MSIbc installed, and I have tried a manual controller and its still lagging.

I fitted the factory boost control solenoid and it ran 8 psi @ 4k which is about right.

With proper boost control you should be at 16psi by 4k, not 8.

How did you setup the wastegate actuators?

A friend of mine is having the same problem with his GTR, twin GT-RS turbos, 272 cams, etc... Full boost by 5500rpm. I'll find out whats going on when he gets his car back from the tuner.

GT-RS are far bigger and laggier than -7s. Did you mean GT-SS?

A friend of mine is having the same problem with his GTR, twin GT-RS turbos, 272 cams, etc... Full boost by 5500rpm. I'll find out whats going on when he gets his car back from the tuner.

Sounds spot on for those turbos and cams on a 2.6 or 2.8

he said thats whats under the hood, i havnt seen them myself. the car makes 460 awkw though. Would gt-ss make that power??

No way in hell mate, you have GT-RS x 2 there my friend.

GT-SS are hard out pushing 330KW let alone another 130KW on top of that, definitely GT-RS

The actuator rods have a thread on them so you can tighten / loosen them. This would be the first place to look.

Try tightening them up by screwing the end on so the total rod length is shorter. This means the actuator needs to see more boost before it starts opening the wastegate up further.

A friend of mine is having the same problem with his GTR, twin GT-RS turbos, 272 cams, etc... Full boost by 5500rpm. I'll find out whats going on when he gets his car back from the tuner.

Well GT-RS turbos - what do you expect? 800hp of turbo isn't going to be responsive on a 2.6ltr

Sounds perfectly normal - and totally unrelated to the OP as he is talking about R34 N1 turbos.

I'm running a pair of Garrett GT 2860 - 7's in my GTR, and i'm getting full boost are 6k, which is way too high in the rev range.

I currently had a Gizzmo MSIbc installed, and I have tried a manual controller and its still lagging.

I fitted the factory boost control solenoid and it ran 8 psi @ 4k which is about right.

Anyone else had a problem with excess lag in a GTR? Or have any idea why its lagging so much?

Well you've answered your own question.

The EBC install is incorrect. If you've put the factory setup on there and it was instantly more responsive... Then it's rather obvious where the issue is...

Well GT-RS turbos - what do you expect? 800hp of turbo isn't going to be responsive on a 2.6ltr

Sounds perfectly normal - and totally unrelated to the OP as he is talking about R34 N1 turbos.

Well you've answered your own question.

The EBC install is incorrect. If you've put the factory setup on there and it was instantly more responsive... Then it's rather obvious where the issue is...

Well if the EBC is the issue, it would have to be simply doing nothing. By that I mean having the same effect as no boost controller at all....would that really amount to that the increase in lag? Sure, it's been proven to be the issue by his simple troubleshooting - yet I can't see how a boost controller will be the difference in 2000rpm

The actuator rods have a thread on them so you can tighten / loosen them. This would be the first place to look.

Try tightening them up by screwing the end on so the total rod length is shorter. This means the actuator needs to see more boost before it starts opening the wastegate up further.

+1. After you tighten the actuators, make sure they are both working in unison by applying boost to the signal line, and making sure they move together. Otherwise you could flog out a turbo.

For clarity, it appears you have two boost control problems.

1. Probably actuatory adjustment

2. Boost controller installed incorrectly/broken.

+1. After you tighten the actuators, make sure they are both working in unison by applying boost to the signal line, and making sure they move together. Otherwise you could flog out a turbo.

True this - very important the actuators are configured consistently across both turbos.

OK, i'll take a look at the actuators on the weekend, hope they can be adjusted without removing too much

I'm pretty sure the install is correct, there are 2 lines, one for actuators another from manifold. Boosts to target, just takes too long, old controller did the same thing, that's why I replaced it, thought the unit was faulty.

On the note of take it to a pro, can you recommend someone?

Thanks for the input :)

By target, do you mean higher than your actuator's spring rating? Try running a vac line directly from the boost source off the intercooler piping or wherever you're getting it from to the actuators. Completely remove the boost controller from the equation. You said with the standard boost solenoid in place, it made 8psi? If that's the rating of your actuators, I dare say that's probably the issue. While your turbos aren't HUGE, they're certainly flowing a decent amount of air and therefore exhaust even at that low boost, so I wouldn't be surprised if it was just simply overcoming the wastegate flap and pushing it open.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • That still isn't a lot to go on. I don't have a Y50 Fuga Head Unit wiring diagram. I can say that a lot of nissans of that age shared head unit plugs, so if you are in Australia something like this would probably help: https://aerpro.com/app091# You plug that into the car loom, then either plug the head unit ISO into that (if it has ISO), or you buy and ISO adapter harness that you wire in. Bit of stuffing around, but once you have ISO its easy to change things in future.
    • It is a kunfine Android screen . Does anyone know the wirering diagram of the fuga ??
    • just an update to this, poor man pays twice  Tried sanding down the pulleys but it didnt do the trick. Chucked another second hand alternator in the na car which I got for free off my mate and its fixed the squelling. Must have been unlucky with the bearings.    As for my turbo car, I managed to pick up a cwc rb alternator conversion bracket + LS alternator for 250 off marketplace, looked to be in really good nick. Installed it , started the car and its not charging the battery.... ( Im not good with auto elec stuff so im not sure if this was all I needed to do but I verified such by using a multimeter on the battery when the engine was running and I was only getting 12.2v )   I had to modify the earth strap for the new LS alternator , factory earth strap was a 10mm bolt which did not fit the bolt on the LS alternator which was double the size so I cut it off , went to repco bought some ring terminals that fit, crimped it onto the old earth strap and bolted it up to the alternator , started the car and same issue. Ran like shit and was reading 12.2 at the battery.  For a "plug and play" advertised kit thats not very plug and play but alas.  My question is , am I missing something ? Ive been reading that some people recommend upgrading the stock 80 amp alternator fuse to a 140 amp but I dont see how that would stop the alternator charging especially at idle not under load.  Regardless ive pulled it out and am going to get it bench tested by an auto elec tomorrow but it would be handy to know if ive missed something silly or have done something wrong.   
    • My wild guess is that you have popped off an intake pipe....check all of the hoses between the turbo and the throttle for splits or loose clamps.
    • Awesome, thanks for sharing!
×
×
  • Create New...