my ride is a vl calais auto with a vl turbo & exhaust manifold, 2.5inch straight thru running 10psi, with detonation over 8psi. No intercooler, just that done to it nothing else, like standard rb30e computer and injectors, fuel pump etc. How can i stop this detonation? I cannot lower the boost any lower than 10psi it wont happen! Putting out 124rwkw dyno proven, which isnt bad for the time and money ($500) that ive spent on it. In the process of plumbing up an intercooler, would this help? Any help much appreciated

cooler will definatley help but running a std comp and injectors will be working against you not to mention the std pump. Don't do things by halves and learn the hard way, take your time and do things properly. You'll save money and lots of heartache in the end!

but...... ive had it on my work's tuning equipment and lambda link not leaning out and injectors aren't maxed out. Everything seems ok except for detonation, yes intercooler will help but what if it still detonates? where to from there? lowering compression ratio? but some turbo vehicles are running 9.0 : 1 without any problems

higher comps are easier to run with better breathing heads, big cams and bigger turbos. Running a high comp engine like yours with std turbo, head, exhaust and no cooler is asking for detonation. See how you go with the cooler, where's the timing set at???

12 degrees btdc and cooler takes up a substantial amount of frontal area, which is good and looks horn. But in saying that wherever i have the base timing set at it still detonates at over 8psi. So how would i go about getting a vl turbo computer as they are very scarce over here in NZ, and cant afford aftermarket engine management. What about running 2 vl fuel pumps in paralell?

Running premium octane fuel, upgrading your injectors to turbo items along with hte comptuer (buy from australia?) and lowering your boost (modify the wastegate or make it longer via the threaded bit where it connects into the flap). If you want to stop that detonation, take the timing right back and wind your boost down till you got a reliable system. You should have a cooler, even a small import one modified to suit your needs. Look at www.autospeed.com.au (http://www.autospeed.com.au) for the intercooler comparison they did. try a GTR core and custom piping if your keen. Do a search in these forums about conversions - you should be able to run 10psi with a cooler on a turbo computer/injector/fuelpump setup.

i dont have a wastegate, its completely disconnected and flap wide open, still goes to 10psi, cant stop it. Ive tried backing the timing right back but its a sack of **** down low until like 50kph when it hits boost. I'm using water, but i dont know where its going and a brown sludgy deposit in my radiator, any ideas? And yes, vl's can drift very well!!

What i have read dosent sound too promising mate, if your loosing water and you have sludge in your cooling system id say yourve either cracked the head or blown a head gasget.

yeah doesnt sound too promising, and just as i thought, a blown head gasket or cracked head. Thing about the boost is im running a .36 exhaust housing so its quite small, if anyone knows, are the cracks normally quite visible in the head? I'm losing about a litre every three days

Yes the cracks are normally visable, just remove the cam and look down the cam tunnel.

oh so i dont have to remove the head from the block they are visible from under the rocker cover

brown sludge = destoryed head.... Some original photos have not been recovered yet.

I've got a couple ideas. 1 .36 exhaust a/r. That is damn small, thats probably why you are detonating. Ever heard of reversion?!?!? 2 You said you are running premium. Are you running 95 premium or the 98 octane ultimate/synergy 8000? My car running the std. 15degree & stock boost used to detonate on 95 premuim. Not on 98 though. And for the head. If you detonate too much you will do the head gasket in & possibly break a little bit of the spark plug's ceramic off which can (if you have a ceramic exhaust wheel turbo) break the turbo. A mate of mine cracked a head on his VLT when coming back from interstate. He pulled the head off, cams etc. The head turned in to two small heads. I doubt its cracked providing you have kept the water topped up and its been detonating. Most probably a head gasket due to detonation. Some original photos have not been recovered yet.

im running 98 at the mo and no i havent heard of reversion. what is it? it sounds bad like pressure waves going backwards harming the scavenging effect of my cylinders am i right? ... in not running a ceramic wheel, the turbo is off an L 20t skyline, i cant for the life of me find a .60 upwards housing. i feel sorry for your mate damm. thing is the car has just stoppd using water for the past 5-6 days i dont no what the f u c k is going on! even the rb20det skyline turbos have a .36 rear housing pathettic really.

The RB20/25 turbo's both have a .61 exhaust a/r housing. The exhaust wheel is slightly smaller with the RB20t turbo compared to the Rb25t turbo, hence why the RB25t turbo spools around 400rpm slower to its set boost on the same motor. Then there's the VG30BB Ceramic turbo that has the larger .81 exhaust housing. The VG30BB turbo has a larger exhaust a/r however its compressor is smaller than the RB25t compressor but still slightly larger than the RB20t compressor. The RB26DETT turbo's from memory have a .43 or .4 something exhaust a/r. Could be wrong about the 26dett but. My RB20DET made 15psi by 3400rpm in third gear accelerating from low rev's. Usual mods 3" Turbo back exhaust, CAI, FMIC. I'll be glad when the RB20t is out of the car and the RB30t in. The only problem is I can't take the car off the road as I need it for transport at the moment. Will be done mid-term holidays. PowerFC, 550cc injectors, HKS3037. Can't wait. Some original photos have not been recovered yet.

well i diddnt no that thanks for your help man maby i should just go and get a rb25 turbo and slap it on and yea get that rb20 out and the 30 in youl love it. my car just keeps getting slower and slower every day starting to miss real bad under any boost think it could b the fuel pump ,fuel reg or airflow meter, has never done this b4. im having so many troubles im thinking of going back to na but just cant do it i love having boost. im a auto sparky by trade so ill b able to figure this prob out when i got time. its just the turbo side of things i need a little help with, what you rekon i do. and sounds like your car is going to be awsome id love a factory turbo vl but this f u c k n new zealand you can understand that any help much app. brought a stage 2 cam 4 $120 today fu kn score i say

Have you changed plugs? I had a set of plugs that when installing them I accidently cracked the top ceramic bit. At first they were fine with only a slight pop on idle, then a week later it started to sound like it was running on 5 when boost would come on. It would run on five and miss until around 5500rpm where it would smoother out and start pulling hard to 7000rpm again. Plugs out checked them (couldn't see the crack) put them back in and they were way way worse. Pulled them back out and finally saw a dirty old crack. (that will teach me for trying to use a swivel instead of simply removing the inlet cross over pipe) Stay with boost, it sounds minor. How does it start first thing in the morning? no misses and carry-ons that require a rev to get it going? I disconnected my inline Bosh external pump once. Felt a little punchier down low and in the mid as it wasn't running as rich. Gave it a run through the gears, as I started to wind out third I looked down and saw the temp guage starting to rise above half, next thing I heard the worse rattle/detonation I had ever heard. I backed off straight away. Crusing along the car was running on 5 cyclinders, Pulled over with the car lumping over thinking to my self sh*t you **** head why the f*ck did you disconnect the fuel pump. Drove off really really slowly short sifting every gear with very little throttle. By the time I got home the car was running on 6 again. Connected up the fuel pump and has been fine since. While winding out the gears the car did feel lethargic without the external fuel pump connected. Some original photos have not been recovered yet.

thanks bro boost all the way ive just purchased some new plugs one heat range down from standard so going to put them in tomorra. starts first comp in morning but runs slightly rough and hesitates. sorta the same symptoms as youve explained. thanks joel your a good man

yea it does feel lethargic sorta wants to go and then dosent like pumping the accelerator kinda maby it is a fuel pump

What plugs u running? I run the BCPR6EY (std is heat range 5), I remember reading some where that for every 75-100hp extra you make step to a colder range plug. Stock my rb20t makes 160kw at the flywheel not it is making around 210-220kw at the flywheel so thats around 70hp so close enough. Cooler plugs also help you run more ingnition timing as it removes more heat from the combustion chamber. One bloke I know had issues with the BCPR range of plugs when approaching 24psi of boost. He is making 290rwkw with an internal gated highflowed T3 turbo on a RB25DET in his R33. He changed to BKR7VEX and apparently had much better results. I havn't got off my arse yet to find out the difference between the two sets of plugs. Maybe there is something there that isn't listed in the specs?!? Let me know how you go. I always like to know as much as I can so when I come across problems I can trouble shoot a little better. I feel for you buddy, I remember how much I was stressing when mine was missing while I drove around for 2weeks with stuffed plugs. If it was running lean causing it to miss you will definately hear detonation. Then again my old man gunned his EF ford once when it was playing up, the thing was detonating off its head, I freaked said stop stop he said what, i said can't you hear the pinging he said nup.. Then again I do have good hearing. I can hear the electronic buzz from a tv outside a house.