I doubt it's reading the correct sensor or displaying a legitimate value. The n18 briefly warms up on the conventional throttle, then kicks in the variable valve lift and opens the throttle fully. Apparently it will revert to the traditional throttle in limp mode as well. You can determine whether the throttle is wide open by monitoring boost / vacuum. During normal operation you will notice about -.2IN Hg if you're just driving along, meaning there is no vacuum being drawn against the throttle butterfly. If the throttle is in use, the vacuum will fluctuate as you drive.

 

on a cold start i see 23-24% tp @ 1200-1400 rpm and ~-.5 in/hg
after ~30 seconds, the tp slowly falls to 13-15% and the rpm falls to normal idle speed with -7.5--9.5 in/hg

when the oil temp passes ~75F, the tp raises to 15-17% as the vacuum falls to ~-.5 in/hg

as i drive, i can watch the tp vary with the gas pedal

 

The tiny amount of vacuum while driving and a relative lack of fluctuation indicates that the throttle is not in use.

 

That's just how far down you have the accelerator pressed. You need to look at Manifold Air Pressure (MAP) instead. Cruising at 70mph on level ground, MAP is zero.

I figured this out when I installed a boost gauge on my N18. I never saw vacuum except at first start on a cold morning. Then I'd see vacuum just for a minute or two until the engine warmed up, then it would suddenly jump from -20 to 0. What happens is at cold start, the throttle plate in the throttle body regulates airflow, since it is mostly closed at idle there's vacuum in the intake manifold which is the engine pulling air against the restriction. Once the engine warms up a bit, the variable intake valve lift takes over and the throttle plate opens all the way, remove the restriction and there's no more vacuum in the intake manifold.

If you look at a graph of MAP over time using the Torque app, you'll see how the ECU manages boost and how MAP is zero unless you are accelerating.

The whole point of variable intake valve lift is higher efficiency from eliminating the pumping loss that occurs with a partially open throttle plate.

Edit: u238 beat me to it.

 

Exactly.

One correction, MAP should be showing atmospheric pressure, since it's Manifold Absolute Pressure. The boost gauge treats atmospheric pressure as 0, so you don't have to do the math to determine whether you're drawing vacuum or in boost.

 

i have a friend that owns a transmission shop ... he just upgraded his profession grade obd tool to include minis as he is getting many calls for automatic transmission problems on out of warranty minis

he wants me to come to his shop and plug in ... he says he can read tp and vanos ... so we can resolve this issue

 

Good questions. Yep throttle body is always open except when the engine is cold. That's when you see really high vacuum numbers. Once the engine warms it opens all the way.

Intake runner length is always of less importance than turbo or cam selection in a turbo application. Less but not nonexistent. That why this bolt on helps but can't give you a 50hp increase. I mentioned earlier air has mass therefore inertia. In a turbo application the intake charge is denser meaning more mass per given volume. More mass means more inertia as well so the principle still applies. Resonance tuning is timing the pressure waves caused by the closure of the intake valve to arrive back at the intake valve as it's opening. The returning pressure wave does not bounce off of the intake butterfly but the mass of air continuing to flow into the engine. To choose optimal runner length you'd need engine simulation software like Dynomation running the wave action model to get really close numbers. For a N/A engine you can try to calculate by hand with this formula and it will get you in the ballpark.

max rpm due to mass = 0.0056(cu. inches)2 - 8.89(cu. inches) + 11527
intake runner length = 137532/((.7)(max rpm due to mass))2(.15)(bore)

 

Anyone get theirs in the mail yet?

 

We got one Thursday but are still waiting on a few more parts before the test car (GP2) is coming in. Should be on dyno fairly soon after as we finally dropped below 100 degrees out here.

 

Got my today. High quality. I plan on installing it later today.

 

 

Don't forget us, I want the review. I'm guessing the Mini will need some miles to adapt?

 

what's that extra piece? Is it for those running the stock intake?

Never mind, checked the website again and got my answer once I scrolled down. Standing by for some real feedback👍

 

A picture is awesome feedback for now. Parts look like very high quality CNC machining.

 

Agreed, but knowing Cerenkov, I'm sure he is going to give us some honest feed back on wether this really ads performance, or is just a well machined paper weight 😁

 

I'm having a little difficulty getting the intake to sit flush on the spacer. The spacer changes the angles and intake manifold really needs to pivot differently from the bottom but the lower intake manifold support bracket prevents this and I don't want to use the bolts to try and draw it in since the head is aluminum.

It's time for beer, steak and football...I'll finish this tomorrow.


BTW - Normally the first time that I attempt to do something it takes 10 times longer than it should.

On a good note the intake valves look fairly clean (15,000 miles).

 

Hey, how ya making out ? Hope this goes well for ya. Just wanted to say, referencing that bracket. Bout a month after I got my car, I had to take the intake off. The bracket was a pain. I got rid of it and never had an issue. Also, is your car an N14 ? If you could or don't mind, on the bottom of the intake, there's two electric vacuum valves. Would you be able to tell which electrical plug goes to which ? And how the vacuum lines are routed and where they run too ? Mine is all apart and I forget where they go. I picture would be awesome as well. Thanks in advance. If not, it's no big deal. No worries.

 

[QUOTE="SPRINTCARS;3993833" Also, is your car an N14 ? If you could or don't mind, on the bottom of the intake, there's two electric vacuum valves. Would you be able to tell which electrical plug goes to which ? And how the vacuum lines are routed and where they run too ? Mine is all apart and I forget where they go. I picture would be awesome as well. Thanks in advance. If not, it's no big deal. No worries.[/QUOTE]

No problem. Mines a N18 but I think it would be the same, the intakes share the same part numbers.

 

I was a little concerned about that as well but I figured the spacer was tapered to prevent that. If it's a inch thick all the way across and you don't remove the lower pivot bolt you may run the risk of eventually cracking the manifold because of the uneven preload. Of course removing the bolt may cause it to crack later as well due to the unsupported weight. If you remove the lower bolt does it lift high enough where you could install two brackets with a joggle in the middle and a spacer on the bottom?

And that is how one recognizes a fellow perfectionist.

 

It added zero bhp to my modded mini cooper.

 

Wow! Thanks for the insight! With that type of claim, immediately refuting any claim from the supplier, you'd think we should have some proof! I'm sure your not just some troll that wouldn't supply said dyno sheets to show that this is a 0HP gain product. Please post them so we can contact the manufacturer and let them know that all the R&D they did was for nothing and to close up shop



...(continuing to wait for a non-troll to post)

 

No I'm sorry I didn't mean to come across that way, what I should have said was, installing that on my heavily modded mini didn't change anything, but that's because of all the work I did before. On the contrary two people I know installed it and gained roughly 3bhp. Cravenspeed is a great company, nice people too, I live near their office and buy their products

 

I install the manifold spacer this morning. Definitely had to undo the lower support bracket. Anyone know the torque spec to the intake manifold bolts? I did 15 ft-lbs. It's o-ringed so it shouldn't be all that tight.

***Warning*** - be careful when installing the new longer bolts, it can be difficult to line them up and you don't want to cross-thread the head.

IMO Cravenspeed should include an intermediate bracket so that the manifold is continued to be supported from the bottom. It's now about an inch apart. I wonder of if the test cars never had this bracket reattached from previous carbon cleaning services.



When installed it's not even noticeable:



Now on to put everything back together and go for a drive.

 

That bracket has been off my MINI for over 50k miles. My intake was modified for cold weather application, before they started making cold weather intake manifolds. I've had the intake off several times for cleaning and making mods easier to install. There are no cracks in the manifold and everything works great. If push comes to shove, feel at ease not using said support bracket.

 

Definitely looking forward to hearing how this improves throttle response, tq, hp and MPGs.