R33 Suddenly Very Laggy - What Should I Test?

[Aidan]

G'day guys

As the title says, my R33 has suddenly become very laggy. Boost takes for ever to build up and the car just generally sucks to drive. I'm having more fun driving the getz around atm.

First noticed it last saturday evening. Took the car out friday in the middle of the day and it was all good. Was a very hot day if I recall, and I did a fair bit of driving. Couple hundred K's here and there.

I've had a problem with the gearbox for a while now, its crunches in 4th if I shift too quickly. Friday evening it had a nice big crunch. First time in months. I dont think thats the problem though since the lag is through all the gears. Even reverse. I've gotta rev the car to 3000 just to get out of the driveway.

Im thinking it may be a vacume leak. Have not had the time to do any test as of yet as the christmas season has me pretty busy.

If anyone has any ideas regarding what it could be and what I should do, I'd be very greatfull.

Cheers

NB. Car is an R33 GTS-T S2 - RB25. No modifications to engine/induction or exhaust.

[R31Nismoid]

most likely leaky piping or similar, only way is to go looking for it

[trel]

"I've had a problem with the gearbox for a while now, its crunches in 4th if I shift too quickly. Friday evening it had a nice big crunch. First time in months. I dont think thats the problem though since the lag is through all the gears. Even reverse. I've gotta rev the car to 3000 just to get out of the driveway. "

Clutch sounds farked to me....

[Sheriff Wan]

Slipping clutch wouldn't make the car laggier - it would just free rev once it hit boost and you wouldnt go anywhere at all...

Im with Nismoid sounds like a lieak somewhere, more than likely cooler pipe popped off or got loose on the hot day...

[Don Dada]

Reset the ecu

[Finny]

If it was a vacuum leak the AFM would be reading incorrectly so the car would be dumping black petrol smoke out the exhaust and the acceleration would be very rough.

Check your waste gate actuator.

ignore the wastegate arm needs to be shorter bs it's just an image I found on google to explain the actuator arm

make sure it's attached correctly etc.

Electrical issues usually result in poor delivery, like the car no longer revs smoothly. If there is an issue with the actuator the car will still rev smoothly it's just the turbo won't spool till like 4000rpm.

Yes the turbo will still spool with the wastegate open on a stock turbo it just adds like 2000rpm to the spool and it only gets like 5psi.

Edited December 22, 2009 by Finny

[Birds]

Does anyone think this could be a leak at the exhaust manifold? I have a couple of broken manifold studs at the moment (RB engines are prone to it) and my turbo also seems to be taking a bit longer to spool these days.

[Lukas 33]

Is the car making any different noises at all? Does it still reached the same boost level it used to or will it not go that high? How much different is the lag. Like 500rpm laggier or 1500?

I would say leaky cooler piping or exhaust manifold leak.

[Trozzle]

What relevance does having to rev it to 3000 have to do with it being laggy? Are you saying that it's down on power, and if you don't have the revs up that high the engine will stall? Or at you saying it's as though the gearbox was jamming, or the handbrake was on? Just reading that line is suggesting the latter to me, which contradicts the rest lol

[Finny]

Yeah, there is not enough info there for us to make a guess at what the issue is.

[NZM.031]

what is your boost guage doing??

is the car laggy?? as in boostwise?? or lethargic?? as in just doesnt feel like its going anywhere when you put your foot down??

if the gears are crunching etc.. and you have to rev it to 3000rpm to get out of your driveway... the clutch could well and truly be farked.. which would make it feel like it was very lethargic as the engine would be revving as normal, but only 50% of that would be making it to the rear wheels..

are there any weird or disgusting smells?? if your exhaust manifold is leaking, you will see a black soot or burn mark on nearby components.. aka, on the firewall, or on the head or cam covers.

given that it doesnt have any modifications, therefore, there is little chance of things being tinkered with and coming undone.. id be pointing at clutch.. it is the only wear item and are due for replacment at anything over 100000kms.

if you have a vacuum leak, you should be able to hear a hissing noise on idle.. or a boosting noise on boost. spray some carby cleaner around all your vacuum lines and see which one makes the engine die down a bit.

now heres something that noone has mentioned yet... if your clutch is slipping, then there is less load being placed on the engine, so the more you put your foot down, the more the clutch slips... rather than having the load of the gbox diff and wheels.. so the engine is under what it thinks as less load.. so the turbo wont boost as hard.. like when your driving up a hill, if you put your foot down, the turbo will boost up almost instant, as there is alot of load being placed on the engine, more fuel, more exhaust, quicker boost.

dont forget the difference between turbo response and turbo lag. its two different things that a commonly misdiagnosed.

turbo response is when you put your foot down, and how soon it responds and starts to spin faster.

turbo lag is when you put your foot down and it starts to spin faster, how long it takes for the turbo to actually start producing a positive boost pressure.

cheers

Linton

[SATO GTS]

With the gear box 4th gear crunch, get some Redline Shock Proof gear oil and that will help to elliminate the crunch problem.

If its you clutch get up to speed in 4th or 5th gear and put left foot on the brake hard and right foot on the accelerator and if the engine revs up then your clutch is on its way out.

Cant say for sure about the lag or poor response part with out driving the vehicle..

Cheers

[NZM.031]

With the gear box 4th gear crunch, get some Redline Shock Proof gear oil and that will help to elliminate the crunch problem.

If its you clutch get up to speed in 4th or 5th gear and put left foot on the brake hard and right foot on the accelerator and if the engine revs up then your clutch is on its way out.

Cant say for sure about the lag or poor response part with out driving the vehicle..

Cheers

hey kyle

couldnt you just pull the handbrake on in your driveway and let the clutch out in 1st?? if the engine dies down, clutch is ok.. if the engine doesnt die as you let the clutch out.. clutch is bad.

bit better than messing around with the brakes at 4/5th gear speeds.

[PM-R33]

Does anyone think this could be a leak at the exhaust manifold? I have a couple of broken manifold studs at the moment (RB engines are prone to it) and my turbo also seems to be taking a bit longer to spool these days.

Yep can be, exhaust manifold pressure would be down from the leak and result in a longer spool up. However if it was leaking that bad you would hear it very easily.

[SATO GTS]

Im only talking at speed of 60 to 80 k's which is quite normal in any given city

[Lukas 33]

Im only talking at speed of 60 to 80 k's which is quite normal in any given city

Have a drive on the highway and give it a few hard runs up to 110 or something. As PMR33 said if it was a big exhaust leak you would probably hear it pretty easily. Need more info on your boost, what your boost gauge does when your loading up the engine and need to put some figures on the lag. If you only get to 2 psi and doesnt pull any higher after that etc then definately check your cooler piping for splits/leaking or shitty hose clamps.

[JonnoHR31]

hey kyle

couldnt you just pull the handbrake on in your driveway and let the clutch out in 1st?? if the engine dies down, clutch is ok.. if the engine doesnt die as you let the clutch out.. clutch is bad.

bit better than messing around with the brakes at 4/5th gear speeds.

if your clutch slipped just doing that you wouldnt even be able to drive. when they first start slipping they only do it under high load, usually peak torque in 4th and 5th. get on the freeway and load it up in 5th and compare your speed to your rpm, if the rpm goes higher than it should for the speed your doing then your clutch is mcfked

[Aidan]

Thanks for such a quick and thorough response guys. Have not had time to diagnose the problem yet. Will be free boxing day to test it all out and get some more info.

For now, the following is all I know.

There is no black smome coming from the exhaust.

No irregular noise, though i havn't really been listening to for it. I'll check it next time.

3000 rpm just to get out of the driveway was a bit too enthusiastic. More like 2000rpm. Thats in reverse and my driveway sits at about 30 degrees inclination. Hand brake is not engaged.

When I hit boost, the revs jump up about 1-2k and the car wont really accelerate for a atleast 3-4 seconds. Boost pressure builds slower and its not reaching as high.

@100Km/h its use to sit at around 2.5k now its at about 3k.

From what I understand now, it appears to be poor response not lag.

Thanks again guys. Will report back on the weekend when i've had time to test all my options.

Cheers

Edited December 22, 2009 by Aidan

[Aidan]

Hey guys, so its been a while and well, the car finally gave up. Going down the highway, stopped at a set of lights then wouldn't go anywhere it was time to go. Locked into gears fine, just wouldn't budge.

What I forgot to tell you guys before was that I was messing around with double clutching... Had never done it before and decided to give it a go(I did not just watch fast and furios again). Seemed pretty hard at first but got the hang of it, just cant brake as well. Heel toe is a no go for me. Anyway, a mate of mind spoke to his mechanic and he was saying something about double clutching in the 33's screwing up the syncros or something. I dont know much about gearboxes, but I thought double clutching took the wear off the syncros?

Anyone have any insight to this syncro business with the 33's??

Could screwed syncros be the issue with my car or is it more than likely the clutch?

Need to figure this out before I go out and order a clutch from Jim. Dont really want to get a new one if I dont need it ya know? Money is tight atm.

Advice is much appreciated.

Cheers

[brother_david]

The reason your gearbox is making noises sound definetly like the synchros but i dont see how double-clutching it would make it any worse, have the same crunch in forth, works better if you double clutch it or just dont change it as fast, same goes for a mate of mine on one of his last cars, had the synchros changed=no prob'. The whole 'double-clutch' thing comes from old non-synched gearboxes BTW...

But it really cant be the reason it doesnt rev up as it should, does it feel like the car is struggling to get speed or is it just a lack of power?

Does it rev freely when in neutral/clutch pressed?

Check things like faulty Lambda sensor, AFM, CAS (Cam Angle Sensor, in front of engine) or if the turbo is blown, should give alot of smoke though.

Other things like bad compression for some reason, might be blown headgasket, still should give smoke but get a comp test done if needed Had a customers Celica ST205 running like crap, didnt smoke but the headgasket was blown and was actually leaking small amounts of cooling fluid from the back of the block!

Have you done the ECU-diagnostics test? Shorting the 2 wires on the top left of the grey diagnostics connector, engine light should lid up, giving you 5 long/5 short signals="All OK" otherwise it just to check in the manual what it says

Edited January 5, 2010 by brother_david