[Mk2] [Turbo] 1.2 bar too much???

[davidmccosh4757]

Opinions on this please.... [BTW Rev 2 tubby, 65K]

Mods: Fensport Stage 2 CT26;Berk Intercooler;Apexi induction; DP, FCD, plugs etc

Running 12 psi actuator

Was running through Greddy profec b spec 2 soleniod, with boost controller off, and was hitting 1.2/1.3 by about 4k and was still climbing

Took it to rolling road; Guy found out boost controller was faulty, so put a piece of pipe between compressor housing and actuator. This had a small jet in it, as i had said i would like it set to 1 bar.

Don't think car was driven on road; just setup on RR; so when i picked it up and took it for a drive car was still boosting like mad!!

Now i have replaced this pipe with just a piece of piping [i.e. took the jet out] and car is running great.

Finally after weeks of head-scratching i can hold boost.

now, it shoud only be boosting to 12 psi..right??

There is a fairly free flow system 3" turbo back, so a bit more would be expected??

Greddy still functioning only as a boost gauge; recording peak boost of 1.2 ish (think hard in 3rd gear)

Normally it's boosting to slightly over 1 bar, but i am just worried that the occasions it's hitting 1.2 is dangerous?

Should I be worried??

Sorry for long description...but I'm excited as I see light at the end of the tunnel

Regards..

[Pitcher]

I dont think peaking to 1.2 bar is anything to worry about, my boost controller is set to 1.15 bar and on the rolling road has peak to 1.38bar!

Rev2, ct26 stage 2, AVCR, H&S Exhaust, Apexi Filter, HKS headgasket, standard intercooler, 290k km - 303bhp

[THE DUKE]

Stock headgasket won't take 1.2 bar for long.

[jimGTS]

pretty sure hyde was runnig 23-25psi for ages on the stock HG, afaik, its not just boost thats the factor regarding the HG....

[davidmccosh4757]

Thanks Guys,

Blown HG wouldn't worry me too much....provided thats all that happened

[johndgt4]

To be certain you would be well served taking your car for a RR session just to make sure it's not running lean and causing detonation/preignition are these are the real bu$$ers for increasing cylinder pressures and also destroying pistons/rods. As long as you have a safe air/fuel ratio I believe you should be OK.

John

[davidmccosh4757]

John,

Cheers for response.

I did have the car at a RR, with a guy who is very knowledgeable.
He is however a very quiet guy by nature, and doesn't say much

I asked him if the fuelling was OK, and he said "yeah that the fuel pressure was good"

I did set the base fuel pressure myself (35psi). I also have a Sard FPR and a walbro fuel pump...

Hope she will be OK!!

Regards

[Caribbean_Blue]

Running 1.2 bar will be dangerous unless you had the supporting mods.

@ 1.2 bar the fuel mix will be running potentailly lean as injectors would be working at an in-efficant level.

Set to Max at 1.15 bar is the most IMHO.

[zak_godsell]

my old banger has been running 1.2 bar for about 8 months with no problems.it has peaked at 1.63 bar .the car felt very fast as the turbo was flat out.the car feels slow now

[Turbo-G]

my old banger has been running 1.2 bar for about 8 months with no problems.it has peaked at 1.63 bar .the car felt very fast as the turbo was flat out.the car feels slow now

If it was the standard turbo your car would have felt faster at a lower boost pressure tbh... CT26/20b would be rather overworked seeing very high intake temps.

[davidmccosh4757]

Caribbean_Blue, cheers to u and others for response.

When u say supporting mods, what exactly do you mean,


According to fensport website, the turbo (ct26 stage 2 hybrid) will run 1.0 -1.2 bar (power up to 290), with standard injectors.

I have Sard FPR, and Walbro FP, surely this will ensure car does't run lean at the end of the rev range.

Also guys, remeber i should't be having this problem, and i can't "set" it to 1.15 bar; as i don't even have a boost controller connected. boost is just running off the 12 psi uprated actuator

[zak_godsell]

did you drive my car when it was overboosting,no.how can you say i am wrong.it was a lot faster

[Century Motorsport]

The fuel pressure being ok doesnt mean your a/f ratio is good. Was there a lambda sensor up the exhaust? you do really need to get this checked out. What Rev is your car? It sounds like your getting the dredded boost creep which can be a problem on hybrid turbo's.

Regards,

Nathan

[davidmccosh4757]

Nathan,

Cheers for reply

Mines a Rev2, seems that it will hit 1 bar pretty quick, hold it, but when the revs go above about 5-6000 it creeps out to 1.15 or 1.2

Guy said fueling was fine, but i'll have to have a chat with him again. He certainly knows what he's at as he works with all local rally cars (scoobys, evo's etc)

Is there anyway this can be brought under control.

Is the fact that it "creeping" to 1.2 bar at the end of the rev range as dangerous as holding 1.2 bar from low down??

Cheers Again,

[davidmccosh4757]

Bumpty Bumpty

[Caribbean_Blue]

I see you have a Berk IC which is obviously good. The main concern is your injectors 440s on a Pre Rev3 at that boost will be working too hard probably up to nearly 100% duty to is potentially fatal. This means the efficiancy of them is drastically reduced which will/could cause lean fueling and bang you have nackod your engine big time.

I have a CT20 Greddy IC and a AVC-R I will not go above 1.15bar which is about 65-70% duty IMHO. 85% I think is the most before becoming dangerous.

Better to be safe than sorry hey. Although cranking to 1.2 bar now and then may be ok but in moderation. Get bigger injectors & and ECU to run them and run 1.2 bar all day long.

Just dont want to see you nackor your car thats all.

HTH
Reece

[davidmccosh4757]

Cheers Mate,

Like I say - its not through choice i'm running 1.2; i wanted 1 bar max.

Just, due to hybrid etc it creeps up to 1.1 ish in every gear, a hard rev out in third will hit 1.23

Good job its not a cossie; or it would already have went "bang"

[matt_mr2t]

I've been running 1.2 bar for nearly 2 years on a CT20b on a rev2 with no problems what so ever.

Supporting mods are, unichip, berk intercooler, HKS exhaust, Rogue downpipe, induction kid, avcr and a gm knock sensor.

IT got a little bit close to det at the top end of 4th and 5th prior to the intercooler being fitted so they retarded the timing slightly.

On another note I have peaked more than once at 1.8bar as the bolt from my mbc came out once and the pipe on the avcr came off the actuator once!

Sill runs fine.

[tubby_tony]

1.2 bar here for 18 months now with supporting mods (see garage) and std internals. Actually mapped to 1.3 bar but playing cautious.

[Caribbean_Blue]

I've been running 1.2 bar for nearly 2 years on a CT20b on a rev2 with no problems what so ever.

Supporting mods are, unichip, berk intercooler, HKS exhaust, Rogue downpipe, induction kid, avcr and a gm knock sensor.

IT got a little bit close to det at the top end of 4th and 5th prior to the intercooler being fitted so they retarded the timing slightly.

On another note I have peaked more than once at 1.8bar as the bolt from my mbc came out once and the pipe on the avcr came off the actuator once!

Sill runs fine.

Fair enough. Yours is Mapped though so obviously safe(r). I bet she took off big time at 1.8 bar!!

1.2 bar here for 18 months now with supporting mods (see garage) and std internals. Actually mapped to 1.3 bar but playing cautious.

Your running 540 injectors he isn't he has 440's. And again Mapped.

I obviously wrong hear, so fair enough, I would rather play it safe. If I were him I would be a decent boost controller to stop/reduce spiking boost then sorted.