benl1981

Marks a good tuner - id just get it done there

Hey fineline. What about the hose that takes the blow by from the rocker cover? That is connected to the rubber intake pipe. Should you block that so you dont pressurise the top half of the engine? Cheers

Well after adding gasket goo (to intake plenum gasket) and blocking BOV I am still getting huge boost loss after 5500-6000rpm. I am just dropping my cat to see if it looks collapsed. There is no evidence of leaking at the plenum gasket now so I think that's sealed. I will make the pressure tester and check the inlet tract. Only other thing I can think of is weak valve springs but you wouldnt think that would change in a week!? I guess my centre muffler could have issues. **PROBLEM SOLVED*** modified stock snorkel not allowing enough airflow or sticking to bonnet

2 door exhaust is shorter as 4 doors are about 10cm longer. I think I have a 2 door exhaust on my r33..fits ok just sits further back

Nice work fineline. Where were the main boost leaks? So you attached the inlet pipe you made to the trubo inlet hose? So you are effectively pressuring up through the compressor side of turbo? Cheers

Sounds like a good little idea here. Might make one up. Did you have the throttle open so you pressure the penum also? Did you use an air compressor or just pump it up by hand? Thanks a lot

Mate. That isnt the problem. On the dyno and the first week I was really happy. Would boost to 7000rpm. Something has changed and boost drops after 5500 to 6000rpm hugely.

Ok I'm waiting for the goo to dry so I can test it. I used a small smear of this all the way round. The GOO Seems like it bonds quite well. I know it's not really the intended use but if it works it works. If it works for a few runs then blows out Ill invest in a new gasket and washers I have also put a 50cent coin between my BOV and the intercooler pipe (blocking it off). Will this do any harm to my turbo if I do a couple of runs at 18psi!?? I imagine the pressure build up on gear change and stalling on the compressor couldn't be good. DisplayImage.asp.jpg

So Adriano, do you think wack the old gasket back in with some goo? I can't see any holes in it. Anyone got any ideas from the photos?

I'm just thinking that maybe I should have blocked off the BOV first to test that. I can't really hear heaps of air escaping so I was thinking it may be the standard BOV venting back into intake (would make sense). Do BOVs fail like this sometimes? It was working fine for a week - now something has happened. Anyone used gasket goo on their old gaskets? THinking of wacking it backtogerther with a gasket goo so I can check the bov.. Wont get the new gasket till Monday!

Did anybody get these or they never kicked off? Cheers

Just searching and found this. Is the standard gasket combined with gasket goo the way to go? My old gasket appears ok but there is evidence of it leaking. Wondering if a new one will hold 18psi or I should gasket goo it also..

I'm waiting for the new gasket from nissan..

Yeah we checked that. But I think it is only under high boost/airflow that it is actually leaking.

It was running fine. The actuator arm was checked prior to install. It was holding boost to start with.. Thanks anyway.

On an R33gtst I did it without splitting the plenum. Wouldn't recommend it unless you have to. R34 may be dfferent though, since they have top feed injectors. Get a few more opinions or check it out for yourself. I just split the plenum, so if you want to know some tricks have a look (thread near top now). You need a set of ratchet spanners

Sure, but I didn't think it was necessary to the problem - I'm hitting close to 18psi and the boost drops off massively after 5500rpm to 6000rpm.. I have put up mods in rb25 turbo upgrade thread. dyno result and mods 247.4rwkw R33GTST Z32 AFM GCG High Flow - R33 exhaust housing (not vg30) 3" Batmbl bellmouth dump --> Catco Cat --> 3.5" Kakimoto with 2 mufflers S15 injectors 450cc Tomei Fuel Pump Turbtech boost valve 18psi - running back to 16psi Stock Airbox 450x300x76 FMIC (Justjap)

Hi there, I'm having a problem. Just had a tune on the rb25det. Made 247rwkw at 18psi boost. Running great, power to the redline. After 1 week I have noticed boost is dropping off massively after 6000rpm. Still hits close to the same peak but soon after the boost drops off to less than 5psi. I havent changed anything. - Exhaust manifold looks ok (no broken studs or soot) so too does the manifold to turbo. - Checked intercooler pipework. I have the metal piece in intake pipe so it shouldnt be sucking closed. I got the tuner to have a quick look and he thought it may be the intake plenum gasket (between the 2 halves). It doesn't appear to be leaking at idle but might be under boost. There was a little oil around the join. Anybody got any ideas? Have you had a similar problem? Also, you need a ratchet spanner to take the top half of the plenum off (for the 5 bottom bolts). Crack it first with a normal spanner (otherwsie you break the ratchet). Also, wear gloves or wrap your hand in a towel when doing this. I sliced my hand open trying to crack one of the underneath bolts. That is by far the hardest part of the job. You have to disconnect the crossover pipe etc and take the throttle body off and hoses. Also, leave all hoses attached to the AAV at the back, just undo the 3 bolts holding it on. The gasket is about $85 from nissan. Will get the part no. and add to thead. Anybody know if there are good aftermarket ones? Hopefully the gasket will fix this problem. Can't think of any other potential problems. I thought exhaust restriction butthat wouldn't have been so sudden I think. The exhaust is 3-3.5" the whole way through with catco high flow cat. Notice the oil residue? Any comments? Gasket in place: Gasket by itself: Oil in the ports is this normal? Looks dry? Is this a low point wear it rests? $29 Ratchet spanners. From bunnings. Good for a lot of things on the skyline. Should have had them a year or so ago!

The mechanic reckons I should just change the gasket without even running it on the dyno. They reckon theyve seen a lot of this on the rb25s. It isn't always that easy to hear apparently - and under load there is so much air floating around there with the fan going etc.. Will have a bit more of a check myself.. Nissan want $85 for one! There was a little oil residue around the join. We cleaned this off but there isn't really much coming back. Might run it up onto boost a few times and check again. I did a few 0-100km/h runs the other day which may have blown it apart..

I know the AFM voltage is down on what it usually is. Usually got to 4.44v now only 4.3v..

What do you think then? Hopefullly not head gasket or something.. Might get the mechanic to put it on the dyno and then we can see

Would you normally hear a leak? Boost is dropping pretty quickly after 6000rpm..

I think I have a similar problem. Had it tuned running 18psi no worries but after a week of driving it doesn't seem to hold boost. After 6000rpm the boost drops from 18psi to about 5psi. I can't hear any strange noises though.. I dont think its the inlet sucking closed as I placed a metal pipe in part of it. It looks a little weepy round the plenum gasket. Hopefully thats it.. ANYone got the part no. for R33gtst?

Anybody with 2535 or gcg monitored the boost build in 1st? Please let me know if you have Cheers

So does anyone know what the values in the INJ MAP mean. Are they referenced to a base map and a percentage of the base map setting? e.g. some are 1.01 and as you go down the vertical axis they usually become higher e.g 1.40