donmik

This is the idea of this thread, to brain storm ideas, not be ridiculed over basic items... We have a few more tricks up our sleeve to try, but my gut is pointing to an electrical issue, the car is just too on song to be mechanical... Although it is not being ruled out!

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LOL GTSBoy, I think you need to invest in a leap frog... They are a wonderful device that makes learning to read a breeze... they have all different age groups available so im sure you'll find one to suit you... For the rest who can already read, CAM TIMING IS NOT THE ISSUE!!!!!! I know this cause it has been checked, double checked and then triple checked by a few people, using the correct equipment. Including the engine builder himself, who happens be be me!

As mentioned above: Cam timing IS NOT the issue! Please understand this "Fact" Thank you.

I like hypergears suggestion!! As for cam timing, I noticed the suggestions of using a degree wheel... Use a degree wheel for what? Does ANYBODY out there have the standard OEM camshaft timing specifications? IO/IC/EO/EC & LSA for advertised AND @.050" specs?? If not then a degree wheel is useless... The only way the cam timing is out on this engine is if nissan cut the key way in the wrong place... (highly unlikely) Please stop wasting time with suggestions of cam timing! Thank you!

Very impressive! However I wouldn't be so confident in saying others don't have a vast knowledge in these fields... Whilst your theories maybe great on paper, they are merely that, theories! once applied in the real world factors change! But im sure you know this as obviously you have machined and built your fair share of engines.

So back to the original issue, after running some test with blah_blahs car tonight, I am confident in saying it is indeed the turbo which is not suited... (By no means am I saying this turbo is no good, as a matter of fact I think the numbers it has put down are quite respectable) The turbos biggest set back IN THIS APPLICATION I believe is the internal wastegate (which most of us assumed anyway) I played around with the actuator preload with no improvements, and got to the point were I totally removed the line from the actuator and blocked it... I still couldn't get it to hold over 24psi... Which only indicates to me, the back pressure is far to high and forcing the gate open under its own pressure! Thats all I have time for!

Let me ask this... Do you even know what your talking about? The fact that you are using big technical words only tells me you have no idea what you are talking about so you are just trying to confuse everyone...

Im an odd type of guy... Many years ago, back when we used flow benches, we were building a race engine, target power was just over 600hp.... Selected aftermarket heads for it, to which we copped a lot of criticism for as "they won't be big enough" Done our port work to it, and got them flowed... People litrally laughed at the results and mocked us... Went ahead and bolted the heads on, and sent it to the engine dyno... 650hp... So why would I choose to use a flow bench again?

Are you talking about flow or volume? Volume can be measured the same way a chamber is checked... But once you've been doing this for over 10years you start to get the hang of it... Where as many people thrive to get perfect port volumes, the fact of the matter is there is a lot more other important things to consider, as a few cc difference in a port is not going to tarnish a whole engines performance.

Nah, no flow sheets for the head. Due to past encounters with flow benches and results, I refuse to use them.

......Ummmm, cant say I totally aggree with you there hypergear.... A compressor map is made up of the efficiency islands based on a range of factors... one being shaft speed! As whilst I agree its probably not the most accurate way to tell, it is very evident that blah_blahs engine has already gone over the maximum "efficient" shaft speed of 145,000rpm... What causes the shaft to rotate? The turbine wheel! Another interesting fact I learnt today talking to the right people: An inefficient engine will run a higher timing advance to allow the extra time required to burn the a/f.... The more efficient the engine the less timing it will require with no power loss...

Ps. I Love scones!

I get and respect that scotty, dont think im trying to put you down or get you upset! I do believe a larger housing will have a minor effect of the lag, but I wouldn't class it as a lag "issue" Its a circuit car, get it to boost and keep it there! Are you saying fuel quality could be an issue?

Less power? I believe peak power figures were same, and what is power anyway? Torque x rpm? Why did the new motor create 30 more Newton meters of torque?? Cam timing is not the issue! If you cant get those exhaust gases out quick enough, it is eventually going to reverse flow back to the valve, those gases carry extensive heat, especially in the first stage of the burn process... more then enough heat to act as an ignition sorce for the fresh air/fuel trying to make its way into the bore...

That was your choice and I respect that... I personally would rather build a setup around the motor, not a motor around a stock set up... Do I think the motor is more efficient now? No... Am I positive it is more efficient now? Yes!

I get it, and I under stand a standard head will flow good enough, but this engine isn't wss based on "good enough" If you were getting an engine built, and the set price was X amount for a standard build, but you had the option of a race set up at no extra cost, what would you choose?

Ps. We discussed the option of e85 and it was not considered a future option.

I think you maybe right hypergear, I dont think the internal gate is doing many favors, by no means am I suggesting your product isn't a good product, im just saying for this application we are pushing some serious boundaries... As for what a race engine is, im not saying it has to rev to 11k, but the last thing any engine needs, especially a track engine where WOT is held for long periods is high brake specific mean pressure! Strength is one thing, durability is another... With the right size rear housing this engine will hold 7000+RPM for a lot longer then any stock motor will before reaching any problems! If you are chasing a 300rwkw car there is no use building a motor that will max out at 300rwkw! The idea is to build an engine that will stretch to 350+ and then detune it... That there is strength and reliability!

I wouldn't say "too much" porting.... Yes we did go excessive for his current setup, knowing that in the future we were going to go bigger... Lastnight we plotted blah_blahs engine on a GT3076 and it is coming up too small, its outside the efficiency island and in overspeed... Blah_blah wanted a race engine and thats what he has... The engine wants to rev, now the bolt ons need to support this! (And im jot just referring to turbo, there are many other areas that need attention)

Agreed Scotty, in this case it did make it worse, and we knew it would... But the motor was built with race in mind, although its street driven! Having said that, in my opinion and to a certain point I believe bigger is more effective for race purposes... The motor has been done for future modifications pending... As we would much rather work with changing bolt ons then removing and re working the engine later in life... Ps. I totally agree about reving an rb, but what the customer wants the customer gets!

Tonys engine was built with high rpm in mind... Hence why it is making boost later then most engines with the same set up.. Porting a cylinder head dramatically changes flow characteristics... and whilst I won't disclose what was done, it was major port rework... I don't doubt the power will jump with an open exhaust, but I still feel it wont unleash the full potential! Ps. And I do understand there are other aspects that need rectifying for example; heat control, intercooler plumbing... just to name a few

Seeing the way the car hits boost and how quickly it hits max boost leads me to believe its not an exhaust restriction (it is running a 3" turbo back exhaust) Being a 3" right through would make me "expect" a higher power figure before the exhaust system came into question... I have seen the same turbos make higher power figures on stock motors, but this motor has a very highly modified cylinder head, which in my opinion is causing the turbo to over speed too quickly... What works on a standard configuration will not necessarily work on this one... As for the boost drop, COULD the standard bov be bleeding out once it spikes to max boost?

I'll give you $10 for the gay engine cover!