rob82

Seems weird that they wouldn't mechanically limit the maximum camshaft phase angle on STD engines. I hate the though of software controlling the maximum phase angle. I've had to do the same thing on some of the 3v ford v8's when they upgrade the camshafts - never had any issues but still make you nervous. I'm assuming 50% drive is your neutral position? If so make sure you limit your max and min pwm drive to around +/- 10% from your neutral drive. Not sure if you can setup cam error tolerances with the link but you would probably want that too so that if you error is too great for too long it will go back to neutral drive. Be careful with running too much proportional gain and make sure you inhibit control below say 1500rpm.

I reckon there would be enough room to get the LS2 or AEM coils under the coil covers. You coud allmost just use cut down OEM LS2 coil leads too.

Mostly STD engines....

I've heard plenty of RB engine's ping at low rpm high load and the knock sensor hasn't reacted, thats tuning with either PFC or factory ECU. I wouldn't recommend tuning based off feedback from the OEM knock sensor, use it only as a guide along with a proper chassis ear and good understanding of what an engine does when it is detonating.

What would car manufactures know about building engines..... Every new model needs to make more hp, less emissions and better fuel economy. Changing to a higher compression ratio is not an easy change considering the extra thermal loading on turbo chargers and catalytic converts coupled with the potential for higher NOx levels and less resistance to knock. They usually run high quench zones to promote central flame propegation and the fact that detonation usually propagates at the outer edges of the chamber. Look at the 335ci engine or L3T mazda engine or VW golf they are all running high compression ratios couple with Direct injection. Now when you have a higher octane fuel - in order to achieve the full affects of a highly knock resistant fuel is to increase the compression ratio. I dont see the point of running "big boost" when all your doing is running the turbocharger outside of its effciency range. And average cylinder pressures dont increase expotentially with power... You would probly find that a well setup 400kw car would have similar cylinder pressures to a 500kw car, its just the 500kw car has higher cylinder pressure at a higher rpm.

Well that's definately a different way to look at things.... When was the last time a high performance car manufacturer reduced compression ratio or quench in a newer model? Higher compression will make the engine more efficient everywhere. Now couple that with a highly knock resistant fuel and you will have a good engine. You need to look at your compressor map and see where the turbo needs to run and then choose the compression ratio based on the fuel and boost you need to run.

I would be more worried with block integrity than cam choice. I think you could achieve that power with a smaller turbo and a well setup engine on e85. (gtx35r, 10:1comp and around 256deg cams at 10mm lift)

Makes sense to me. Closer to the chamber the better.

If the manifold favors cylinders 1 and 2 then it is likely that these are the lean cylinders - which most likely means you've overheated(melted) a couple of pistons. Hence the comp will be low.

That's a pretty bold statement. Have you seen the intake manifold to make that conclusion. Generally unless you've overheated the crown you won't notice detonation via a borescope. If you dont know what your looking for then get an independent failure report.

Yes but I bet your engine builder torqued the crank bolt up to factory spec..... So many don't - that's where I believe the issue lies, as it will induce a load at 45degrees to the axis of the crank when loose. Problem only really exist on short drive cranks.

Plug 740 engine hp (which is approximately 505rwkw) into any ET calculator with 3500lb car and your pretty close to 136mph. So I would say the dyno figure is pretty close to 136mph....

What fuel? That's good power.

Yep - generally the higher the torque the greater the cylinder pressures so the higher harder it is on the ignition system... I haven't try these coils on an xr6t, because they wouldn't fit very well but the are probably one car that really pushes a coils ability and I know just the car to test on. If I get to test them on that car I will let you guys know how they hold up? Also the only other downside is that they aren't cop...

I'm about to turn up the wick on a certain engine that will be in the vacinity of 2000hp with these coils - currently at 1260hp and no issues with 1.1mm at 18psi. Have seen them not misfire with 1.1mm gap at this boost with mixtures as rich as lambda 0.67. CDI is good if you want high peak secondary current and minimal dwell time - issues I have with CDI is eletrcial interference and low spark duration coupled with extra cost. Only thing with these coils and LS2 series coils is the dwell time can be as large as 5ms at 14V for full spark energy which can be a bit much on non sequential setups with rapid accelleration rates and flat shifting. Doubt most people would run into this issue though.

If the volume of the plenum (volume between tb and runner division) is large enough it won't be an issue.

Your correct, generally big gaps require larger peak secondary voltages due to the increase resistance and yes as the equivalence ratio decreases the ch3 ion reduces meaning it's even harder to fire. Don't assume that the chamber temps will go up with lowering equivalence ratios as it normally not the case but can be so on slow burning chambers. Unfortunately though ethanol based fuels do have a lower Reid vapor pressure and high flash point than normal 98oct fuel meaning that it is harder to ignition or less volatile - hence the reason cold starts are difficult under 12 degrees c.

http://www.aemelectronics.com/high-output-igbt-inductive-smart-coil-1240 This is what I would use - best inductive ignition system I've seen. I tend to prefer running inductive ignition system compared to cdi on almost all applications - especially on street cars.

Being on the lean side in a SI engine will generally always improve fuel efficiency as your reducing your pumping losses. I would be looking running around 1.1-1.2 lambda and see what you get. Yes the engine will feel less responsive but you will increase your fuel economy. I would also run the largest spark plug gap you can to help complete the burn.

I'm not sure your getting what lambda means... I think what your really searching for is the leanest mixture you can run without causing drivability issues or engine component failure? I think what you really need to do is to compare egt's vs lambda and find the sweet spot it will vary more so with load.

I think what ash is trying to say is that if you have a perfectly tuned car running a z32 and convert to an r35 sensor in 80mm pipe and retune you will not pick up any power(in a single turbo/afm combination). Believe me I've tested so many aftermarket parts that don't work. My view from being a tuner is that if you can change a part and gain nothing in just changing the part over it is unlikely that tuning will make any difference.... Note I've run a single 85mm delco maf sensor up to 14000hz making close to 400rwkw (harrop sc ls1)and done nothing but remove the intake pipe, so "unrestricted" 90mm intake and mafless tuned and I gained no hp what so ever....

I would be well surprised if they have microprocessor in the afm... May have some kind of signal processing. I know the output is just a typical 0-5v output. As for tuning i wouldn't be setting it up on a 380kw car - I would get a fairly un modified car and try to map out the bottom end of the curve.

A lot of the newer style afm run a sample tube rather than just hanging the element in the airflow. This helps to stop the issues seen with airflow reversion.

Yeah that power on e85 with 1000cc inj on an rb26 sounds a little high plus that turbo is only rated to about 680hp worth of airflow too. Must have the world most efficient engine....

Wow that's a pump, over 5l/min at 80psi - that's awesome!! Anyone tried one or got a cost? Sorry just read the thread - have you tested the return flow to see if it matches the specs?