High Revv NA Setup?

[noAE86]

Originally Posted by JohnATL

I plan to stay N/A and pair it with maximum DD weight reduction. Goal is 225-250 WHP and 200-300 lbs reduction (Driver weight is calculated in my goal

in the past when we had to loose extreme weight from a already light car we did these...

chromoly tube rear sub frame, (massive savings in nissans)
chromoly tube engine crossmember and mounts, and gearbox crossmember
kevlar boot/door cards/lower dash,
smaller toyota alternator, bolts cut down to mininum lenth/thread

not for everyone or DD but you can go crazy when it comes to weight savings, at one point we even had ae86 carbon fiber engine crossmember made, it was stupid light, but our engineer was concerned with vibration fractures,

[yuli8466]

Originally Posted by ScottDRFT

Yeah I saw this somewhere also, I'm sure it could rev up to 9K but I think it's capped at 7400 for that sake of preserving engine life.

wow it's awesome. keep it in NA setup. I prefer High Revv rather than sc/tc

[carbonBLUE]

Originally Posted by JohnATL

I plan to stay N/A and pair it with maximum DD weight reduction. Goal is 225-250 WHP and 200-300 lbs reduction (Driver weight is calculated in my goal

I see this being completely possible, I had a 9lb flywheel in my last car lol, helped reponse ALOT, the problem with boxer motors if the valve angle, the k20 had better flow angles vs my Celica, thats why I never saw the gains the Honda guys saw

[Coheed]

I don't see how the stroke of 86mm is an issue for revs. And a low rod/stroke ratio isn't the end of the world for high rpm power. Don't expect 10k rpm efficiency, but 9k could work out.

I'm revving my SR20VE to 8800rpm with power holding until 8500rpm, using stock head and stock SR16N1 cams. It's forced induction, but it just goes to show that you can rev decently with an 86mm stroke.

Also, the 4b11t, SR20, K20 and the FA all have 86mm stroke and bore. The F20c engine is 84mm stroke. It does have a long rod though.

Rod/stroke is 1.54 in a B18 engine. K20 is around 1.61. SR20VE is 1.58. Just food for thought.

[carbonBLUE]

[ame="http://www.youtube.com/watch?v=PjhocJ4QgBk"]2012 Lexus LFA Road Trip: Dyno Test - YouTube[/ame]

someone make it rev like this and ill be happy

that thing gains and loses revs so damn fast....

[arghx7]

Stop comparing this engine to a Honda engine. It has a fixed valve lift. That requires big compromises. And ITB's will be very expensive and hard to control with electronic throttle.

[Turdinator]

Originally Posted by arghx7

Stop comparing this engine to a Honda engine. It has a fixed valve lift. That requires big compromises. And ITB's will be very expensive and hard to control with electronic throttle.

ITBs are always expensive. In fact, as has been mentioned several times before, NA mods are always expensive for the HP gains. I don't see why they'd be hard to control as long as you are using a suitable ECU.

I was thinking last night that perhaps a twin throttle setup would be easier than ITBs. Similar to what Ferrari run with separate plenums per bank. We could use two stock throttle bodies and just splice the signal from the ecu to each in parallel. Although i don't know if that electronically feasible.

[brillo]

So stock the redline is 7400 rpm and several tunes are increasing the redline to ~7800. Is there any rule of thumb to knowing what is safe? I wouldn't think 400 would be pushing the bounds of safely but I don't know Boxers like I know rotaries.

[carbonBLUE]

Originally Posted by arghx7

Stop comparing this engine to a Honda engine. It has a fixed valve lift. That requires big compromises. And ITB's will be very expensive and hard to control with electronic throttle.

ITB's may be stock next year, and like TADA said, everything that comes out in future 86's will be compatible with first year batches if we want, that means we can just buy the stock ITB's, and get a 2014 tune to link them all up

Originally Posted by brillo

So stock the redline is 7400 rpm and several tunes are increasing the redline to ~7800. Is there any rule of thumb to knowing what is safe? I wouldn't think 400 would be pushing the bounds of safely but I don't know Boxers like I know rotaries.

really depends on g forces and what testing the engine went through before it was put in the car
for example 2zz-ge one year the car had a 7200 rpm redline, the year i had, had a 7800 rpm redline and a 8400 rpm fuel cut off, i tuned it without changing any internals to 9000 rpms during the beginning before i went all out. for all we know this engine could be safe to 8400 and run reliably there every day, until further aftermarket test is done, we wont know what the engine is safe at or when the valves start to float

it could be an easy modification of titanium valves/springs/retainers and see 8500 rpms reliable, ,every day for 10 years... we just dont know at this point and anyone testing it is keeping it secret till its proven to be good enough for its customers

86x86 bore/stroke is perfect for high revving, here in 2 years dont be surprised if you see a boosted 300whp fa20 with new valves/springs/retainers running 8500 rpms on completely stock block besides the valves/springs/retainers

[serialk11r]

Originally Posted by carbonBLUE

ITB's may be stock next year

86x86 bore/stroke is perfect for high revving, here in 2 years dont be surprised if you see a boosted 300whp fa20 with new valves/springs/retainers running 8500 rpms on completely stock block besides the valves/springs/retainers

Where did you hear about ITBs being stock? That sounds like nonsense.

You can't say 86mm stroke is perfect for high rev, but it can be brought to 8000+ if everything else allows.

It appears we have a rod:stroke ratio of about 1.51-1.52, which is close to the smallest number you'll find on production engines. The actual difference between the piston motion at 1.51 and 1.7 isn't that big mathematically speaking, but OEMs refuse to let an engine with a short rod rev, something to think about.

[Floggin Tires]

Originally Posted by carbonBLUE

ITB's may be stock next year

Originally Posted by serialk11r

Where did you hear about ITBs being stock? That sounds like nonsense.

I think he means these.

Originally Posted by http://www.ft86club.com/forums/showthread.php?t=8025&highlight=2014

In order to make the vertical vortex (tumble) gas into the combustion chamber and intake from the intake manifold, intake port with a septum and TGV (tumble generator valve federated), oriented tumble intake port has been adopted.

TGV is a valve for generating a tumble actively in the low-speed range, close the valve, the easier it is to raise the tumble of the intake air, raising the combustion efficiency and to increase the gas flow.

Intake port with a septum is divided into two parts by a partition wall passage, which leads to tumble intake port as it is oriented.

There are also separate parts by a partition wall tumble intake port-oriented, in the low-speed range while increasing the flow rate leads to a state to pass through the passage of the outer gas engine, easy to make the tumble. At high speed TGV is the is open, and uses the entire intake port.
The state had created an intake easy, pass-through in the intake port tumble. The tumble is sent into the combustion chamber, creating a vortex to fit the shape of the piston head cavity DIs head of the piston cavity center.

Not really ITB's

[Coheed]

Wouldn't it be crazy if they got rid of the TB and just ran dual electronic servos to open the TGVs?

[serialk11r]

Originally Posted by Coheed

Wouldn't it be crazy if they got rid of the TB and just ran dual electronic servos to open the TGVs?

The TGVs are operated by electronic servos. The plastic thing splits the intake port into 2 halves, one of which is blocked off by the TGV. Can't throttle an engine with that.

[noAE86]

HAHAHA so we are going back to old school toyota TVIS systems, but instead of vaccume operated its now electro servo,
(granted one is for tumble and one is for verlocity but still..)
it makes the car feel THAT much closer to the AE86, i love it,

(i have about 6 sets of 20valve blacktop quads and 4 sets of silvertop quads and 3 sets of SR quads in my shop if anyone is wanting quads, they sell for about $100 N.Z$ so about $60 U.S,