Car Way Too Laggy

[GimpyDammit]

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-

[DVS JEZ]

Did u just fit these turbos or did it only become laggy after fitting the ebc?

Have u recently changed cam gears or anything else?

Have u checked the condition of ur cat?

[Aleckr33]

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.

[MrStabby]

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?

[MrStabby]

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?

[N1GTR]

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

[Aleckr33]

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

[Nee-san]

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

[GimpyDammit]

Not sure about the actuators, was done by someone else. Can they be setup differently?

[Juan_2_3]

will probably be the actuator, tighten them up so they open later or

get new actuators that will open close to or at the desired pressure

[paulR32gtr]

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.

[R31Nismoid]

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...

[Trozzle]

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

[R31Nismoid]

Who knows whats wrong, or how it's been installed was kinda more my point.

Anything could have been done really. Or even the EBC settings are backwards.

Sounds like a "take it to a pro" time

[Trozzle]

Yeah I'd say either faulty EBC (doing nothing) or incorrectly installed (hence doing nothing)

[MrStabby]

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.

[paulR32gtr]

+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.

[GimpyDammit]

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

[Trozzle]

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.

[N1GTR]

Unigroup; that is all