Yeah I've read that thread and nearly every other N1200 on the board, thanks for posting though

I've checked the ratio and its just over 3.5 turns so 3.61 sounds about right.

 

The 1200 is more efficient... but this is madness. Try a 4'' pulley and see what that gets you. I see exactly 10.5 psi on a 4.2'' pulley @ 9000. 22psi, holyshit... did they change the gearing or maybe you got one that someone put a wrong gear in and now it goes crazy at higher RPM. Sucks to see this give you so much hassle

 

This has nothing to do with why your seeing abnormally high pressure per pulley size, but you cant go off of their claimed pressures per blower rpm, because the pressures will be all over the board depending on the engine the blower is mated too. Typically we see lower pressures per max blower rpm because our engine is so efficient compared to say a v8 application which I have gathered most their average numbers are based from. With that, I worked out with all the info provided that max 52k blower rpm is reached on our engine at 8350rpm with a 3.2"/5.45" pulley combo. I saw on average 17psi there. And would fluctuate 1psi in either direction based on ambient temps. Never did I exceed 19psi in the coldest of winter temps. With a 3.8" pulley I made 12-13psi.

Sorry if this was covered already, but its my feeling that either the boost reading is inaccurate, or there is an abnormal valve timing or exhaust restriction at play here elevating the boost beyond normal levels. But out of curiosity, what is the output? Does it reflect the boost levels showing or is it substantially lower? There lies more clues as to an engine side related issue. If the power reflects the boost ie 500whp+ Then I see no issue. It would be consistent with the pressure showing.

 

hey junky,

I've check most things on the engine although I haven't removed the cam cover.

I refitted the n1000 kit and the car performs perfectly so that has ruled out engine problems to my mind.

On the very first run on the dyno the car rev'd to 7.5k then cut via the boost cut feature in the AEM. Once this had being raised, my tuner then did a base run and achieved 368whp (18whp more than the novi1000- 350whp @16 psi).

After this we got belt slip and oil pressure problems (See my first post).
The exhaust was stripped and inspected and so was the intake. But again I've fitted the n1000 kit after this and all is good.

The dyno boost gauge, which takes a feed from the intake manifold independently registered 1.54bar pressure.

I would love to try another n1200 on the car but there are non local to me

 

Boost graph looks linear and smooth

N1200


Blue line was the first run with boost cut raised, this was an unmapped run using the novi1000 as a base. After that we tighten the belt but ran into oil pressure issues. Each other pull is when the vtec is engaged at different rpm's to test to see what is going on. They were all completed with no exhuast just a header. Boost pressures were high on all pulls

 

You're 12.9 AFR seems too lean up top. Maybe try a different tuner?

 

Yeah after all im hearing, im becoming suspect of the tuner here at this point as well. It might not be a bad idea to take the car elsewhere and see what you can pull together with them now that the oem issues have been dealt with. Is your current tuner a well known s2k/sc tuner among your local community? Your best pull at 22psi is pretty low at 368whp even in British numbers. I don't know where this guy has your fuel and timing set, but it isn't in the sweet spot I can assure you that. Suspect if thats because he has the tune heavily retarded wile trying to troubleshoot the break up/vtec issue you were experiencing or he really has no idea where his safety/performance window is.

 

The car isn't mapped for the n1200. That is the n1000 map. I did one pull to see what the boost pressure was.

Honestly this isn't runner related. He's tuned my car 4 times now over the years. I've also had my car mapped my Mase in the years that have gone by and I can confirm this guy knows his stuff.

 

Tunning aside the boost pressure is 22psi?. I'll do some more fault finding and report back.

Thanks for your suggestions so far

 

This is gonna sound crazy but I saw something like this with my roots blower. It happened when vtec was not kicking in and I was on the low cam lobe to red line. Might be worth checking out. Once I got vtec to turn on boost dropped back down to normal.