No second turbo, But only during first gear

Has anyone else experienced this, or know what the cause is? it's been happening for a while now and it is consistant.

Sorry to drag up an old thread, but I also get this and have always wondered why? Anyone find the cause of this or experience the same issue?

Mine's always done this too but i was under the impression that the stock ecu limits boost in 1st gear to prevent damage? Surely 1.2bar in 1st can't be good for the gearbox?

lol gearbox loves it but not sure, maybe it tries to limit the boost to reduce spin? or maybe its just the fact there isnt enough load on the engine so soon? not sure just thought i'd add to the thread

Manual or auto? I'm assuming manual. How do you know it's not coming in?

There is no ecu boost limiting strategy that I know of, especially at 1.2bar+ seeing as stock boost is 0.8bar. It's probably load and traction related.

-Ian

Thanks Ian...

It's a manual yes, get the noticable rush from the 2nd turbo in any other gear. Even with the traction control off it's still the same. I can't be certain, but my lame diagnosis is that the roaring noise you get when the 2nd turbo is online does not occur in 1st gear... not a great diagnosis I know !! The performance also seems quite linear where as in any other gear you get the 2nd turbo 'surge' when it's online. The performance also doesn't seem to match what I'd expect of 1st gear with both turbos online, 2nd gear feels like what first gear should! It's BPU'd if that makes any difference...?

It doesn't overly bother me as I'm not one for wanting to destroy my running gear by doing fast starts, just wanted to check nothing was wrong.

Thanks for the help

Sticky actuators? I've seen that before, only happening on first gear

Sticky actuators? I've seen that before, only happening on first gear

Really? How's that possible? Not questioning what you're saying by the way as I don't know any better, just can't understand how a sticking actuator would only be present in 1 gear and not the rest... surely boost pressure is boost pressure or am I missing something?

Response time - if it sticks a little bit, it might not have time to open in first gear before you run out of revs and change gear, but since you hold gear for longer in second onwards, it has time to respond and un-stick. Plus it's normal to make more boost in higher gears which would give it a little more oomph.

I don't know - it's only theory.

Have you got a boost gauge fitted? What values are you seeing?

That was my old supra. My new one does the same too

Mine used to do that before I went single, isn't it a dodgy vsv or something?

Is this not because there isn't enough load on the engine to produce a great deal more than 0.8 bar in 1st?

Tubby 2 is probably coming on, there just isn't the noticeable surge that you get in 2nd when it jumps from tubby 1 to tubby 2.

something defo wrong mine really kicks hard at 4 k in 1st gear

not enough load in first gear, on my na-t single i only make 3psi in first then jumps to 7 in second

Cheers for the replies guys, I'll have to have a look and see what the boost gauge is doing although I could do with a more accurate one I think. So the general concensus is that I should make full (or near to) boost in 1st gear... if I don't then there is something that needs looking at with the sequential system...?

I'll do some tests tonight and see what I find anyway..... thanks for the help

Mine does the same. It does not fully boost in first gear. Having said that I tend to feather the clutch to prevent spin and never really give it full revs so just assumed it was a process of how I used the first gear. Once into second gear the car is as I would expect.

I'm the same as you a TT BPU manual.

If you do think this is an issue I would be grateful for any info people have with regards to what, if any, the issues might be.

Have just been for a spin. I gave it WOT from first to fourth gear. Nice big smile on the face and a lot of wheel spin. First gear is only producing 0.8 bar. Having said that the wheels were spinning and I had to play with the clutch to get the traction just right. Every other gear goes 1.2 bar and in fourth I gave myself a shock by spiking at 1.4 bar on the rev limit :0 Car didn't like it. The engine light came for a few seconds but all was well. Phew!!

I personally don't think there is anything wrong with the the actuator or turbos. Everything felt quite smooth!!?

Cheers for the replies guys, I'll have to have a look and see what the boost gauge is doing although I could do with a more accurate one I think. So the general concensus is that I should make full (or near to) boost in 1st gear... if I don't then there is something that needs looking at with the sequential system...?

 

I'll do some tests tonight and see what I find anyway..... thanks for the help

id say the general concencus is that the car is fine.

Same problem here , its happened since putting the car back on the road after a major service also fitted a fmic and removal the TC using a hks kit , for me it feels like there is no first or second turbo at all first gear is flat as you like, 2nd upwards its fine any ideas ?.

mine is like it too, I just put it down to running out of revs before they get a chance to spool. 1st gear on the v160 6sp is over very quickly.

I've certainly had the second turbo kick in in first gear, as I nearly lost it coming out of a junction on a wet road when I first had the car!

I'm very careful these days though

Auto.

Both turbos should spool up in first gear. Have you guys who are having problems got boost gauge fitted?

Mine has the same problem but sometimes it happens all the way through to 3rd gear, its really annoying as sometime i pull out to over take and nothing happens and all i get is a slow and sluggish overtake, but then sometimes it will come on line, but mor offen than not i dont get any boost from tubby two in 1st gear.

Ive put mine down to the actuator which i am soon to replace, i have checked all of my VSV's and they are fine, im going to check that there is no presure drop across the intercooler. To see if i can get to the bottom of the problem as it is starting to wind me up.

Oh and yes i do have a boost guage fitted and giving a reading of around 1.8 every time soon to uprate to 1.2 when i put my boost controler on.

My new one does this sometimes, the second turbo comes in very late at around 6k in first gear