wantboost

iTrader: (2)

So some background.

I've already done a 2.1liter ls/vtec build with a knife edged and profiled crank. It helped but I know I can go lighter

That motor is long gone, sold it to a friend who spun a bearing. Over 10k in custom **** trashed


Current build is a response car, no big turbos.

A quick run of what the motor will be

Stock sleeve/displacement 1.8l ls/vtec
Arias 10.5:1 pistons with thick walled straight pins
I beam rods

Ported b16 head
46mm itbs
Gsc t1 cams
Divided manifold with true twin scroll turbo (secret ;-))
Pre turbo meth injection and "direct port" at the intake manifold

Competition clutch 9lb flywheel and stage 5 clutch (debating on a twin plate for reduced mass and better modulation )

Torque goal is 400ftlb or close to it between 3-4000rpm

I was going to send my crank to FFWD connection and have their butcher process done
They can remove up to 10-13lbs from a crank depending on model as well as profiling the crank for reduced windage loss and crankcase pressure. They bullnose the leading edge of the counterweights and taper it back to the trailing edge (think aircraft wing)

They have dsms running well over 1000whp without issue, no flexing, etc

They also micropolish the journals, pull the passage plugs and clean/hone/chamfer the journals, plus they balance the crank to .1ounce per inch.

Here's what a butch crank looks like



And their page on the cranks and the process

http://ffwdconnection.com/butcher-1.html

Opinions?

I know going too light can cause idle, low rpm, and issues with getting the car rolling but it's nothing I can't live with. But given I'll be making 450-500whp I don't think I'd be taxing the bottom end in any way..

wantboost

iTrader: (2)

The car will also see trackdays at both Road Atlanta and Atlanta Motorsports Park. Hence the torque goal. .. as AMP is more a 2-3 gear course and requires a decent torque output to have fun

TheShodan

iTrader: (14)

Yeah, I was looking at that Butcher process. I'm a bit concerned. I wouldn't do ANYTHING to the OEM crankshafts. Yes, they do mainly 4G63 & 4G64, but they always modify the 7 bolt cranks. Not necessary for road atlanta. you're running boost, you don't have to concern yourself with a lightweight rotating assembly much.

Overkill, my friend.

Runnerdown

I agree with the shodan. I can't say I have direct experience but for a RR application reducing weight on the crank does not seem like a good idea. I guess i'll pull out the ol "my buddy" thing but I had a friend who ran a knife edged LS crank on a NA street car and it actually broke. I think that losing crank mass will not dampen and absorb harmful vibration as much and could possibly have long or short term relaibilty issues. I think the drag racing stuff can away with a little bit more due to the short bursts. But i'll be the last to tell someone it cannot be done.

mar778c

iTrader: (1)

The question is not about weight per se but when does the process of removing weight adversely affect configuration stiffness and strength. Both of those have a predominant effect on fatigue, stress, and vibration characteristics.

wantboost

iTrader: (2)

They've extensively tested every model of crank they do this process to. They still leave the bulk of the material around the journals, maintaining stiffness and straightness. Like I said they have numerous 1000+hp dsm drag cars and haven't had one issue with flex or a unit failing. They simply recontour the counterweights to be as aerodynamic as possible, which means the only material removed is outside of the flat plane of the crank.

Hell Ferrari and Lamborghini use flat plane cranks and they do the same process. They forge them with full counterweights (like our stock cranks) and then machine all of the material away in exactly the same manner as ffwd

What I really like is how they balance, .1 ounce is even lower than the typical industry "race" tolerance of .2 ounce.

And while this does sound overkill, I'm trying to build the most efficient motor possible. So having this process done means the motor will respond quicker/rev faster. And less unsprung weight in the rotating assembly means less parasitic drag to turn the motor over which inturn means lower drivetrain losses so more hp and tq make it to the ground

I'm also going to do some transmission tweaking to reduce friction and heat, thusa again reducing parasitic drag and drivetrain losses

I'll also be getting a crank scraper/windage tray with baffles to keep the crank as free of oil as possible (again, less winsage losses) the windage tray also has baffles that reroute the oil draining from the head away from the crank and directly into the oil sump so again, you reduce windage losses and parasitic drag since the crank wont be covered in oil that it has to sling off, etc.

The company that makes the scraper is (Ishihara-Johnson) www.crank-scrapers.com

Here's a link to the b series offering (they have units for every motor conceived lok)

http://www.crank-scrapers.com/Honda-Acura_B-SERIES.html

For what it's worth, ill be having the butcher process done to all 5 of my SR20DET motors along with the scrapers

I'm also going to ask them if they can atleast reshape the counterweights on my built VG30DETT motor. I know they can't flat plane that crank but I don't forsee an issue simply reshaping the weights.

I've done a lot of reasearch on the cranks and have talked to people using them and they love them. they say that the weight of the material removed is very noticeable, that tge car revs quicker, responds faster, and makes more power. I've only heard of two cranks bending /flexing and those were some of the first units on drag cars that launched hard. Haven't had a failure since

For me it's about squeezing every last bit of efficiency out of this motor and I don't mind if it takes"overkill" to do so. Hell I'm running 8 injectors for this setup, 260cc primaries for good idle qualities (especially with GSC T1s but I plan on tuning the idle to lope on purpose. That way the rednecks and their stock camaros and "I think im the fastest guy around in my stock v8 pos or lifted truck. I call that the redneck repellant lol) as well as crisp low rpm/ low load driving (it's still a daily afterall) as well as true 550cc shower injectors (magentti marelli units off of a Ducati, 12 hole conical discharge. Fuel looks like fog leaving the injector as opposed to most injectors that have the spray pattern of a leaky garden hose) so I'll have superb atomization for high load conditions

TheShodan

iTrader: (14)

Ok. If you say so.... You know me, I wish you the best of luck. But Honda still has been making racing engines for IRL for over 30 years, and coming back to Formula 1 in 2015. There's something to be said for their engineering. I wouldn't mess with it. But..do you. An SR20DET is not a B18C1, that's for sure.

wantboost

iTrader: (2)

It's still something I'm tossing around

Like I said, everyone I've talked to that has one says they love it vs a stock crank

wantboost

iTrader: (2)

No one else with opinions/advice?

jimbo slice

I was reading this over, and I had a thought : Honda increased the weight of the Type R crank versus the GSR crank. I highly doubt they did that for a 550 rpm increase. I'm not trying to start an argument here, I just realized that the OEM actually did the opposite to what you are trying to do. I'm curious to know if the Butcher process is worth it on our engines also, as I've never modified a stock crank.

D-Rob

If it ain't broke, don't fix it. What do you need 400ft-lbs at 4,000RPM on a Honda for?

TheShodan

iTrader: (14)

I agree here. He's trying to get as much as possible for the circuit. The thinking for Time Attack /Circuit is a little different in which peak power is not at all the most important thing. however, with that said. THAT much torque that early, even if possible is going to be hell to drive on a FWD application. On an SR20DET, that makes sense, and usually occurs. But he has to remember the whole profile of that engine is different than whats needed on an FWD B-series.

wantboost

iTrader: (2)

Exactly, I dont much care about peak power, I need as much under ther curve as possible, especially at AMP, lots if elevation change (150ft) and a lot of sub50mph 90* turns, one of which goes 45* up hill into a blind 90* right hander

So torque is what I need, just ask lightningteg, he made 300ftlb by 4000rpm on a bone stock ls with a 2860, which is slightly smaller than the turbo I'll be using but I'm using every trick I know to get every last bit of midrange possible

wantboost

iTrader: (2)

And you forget these track days will be on a suspension system that cost 3x the car and very sticky full slicks, boost by gear and traction control (maybe, I feel like it takes away from a true driving experience/true driving skill) if the same slicks can keep our 600whp/580tq ls7 from spinning, I think they can handle the civic

wantboost

iTrader: (2)

AMP track layout and test speeds, doesn't indicate elevation changes but we've all dubbed it the "rollercoaster"


I'll have video tomorrow showing how aggressive it is for only being 1.87 miles in length

I do have a slight advantage being I only need to set the car up for one track. So it's all basically constant refinement. We rarely do RA due to high entry fees and very little track time

TheShodan

iTrader: (14)

BBG will NOT help you on that course, regardless.. Either way, I say NAY to the butcher crank

wantboost

iTrader: (2)

Yea I figured the course is so tight and technical that even on the front straight I'd never leave 3rd, best to have good rubber (Hoosier R6 or R1, looking at Achilles offering as well) and let my suspension do the bulk of the work..

Traction control would definitely help at this course, it takes throttle wizardry to leave the 90* turns and not just smoke the tires. However with slicks, I think traction would improve greatly

Using our z06 *600/580 to the wheels* as an example, on Michelin pilot sport cups it would just roast 1st and 2nd. With 315f and 345r Hoosier R6 slicks on CCWs it just grips. I tried to get the car to spin 1st and 2nd but it just won't do it. Shy of a clutch kick lol

exgr

hmm for $700 i'd like to try this. 23% reduction in rotational mass = mucho engine response as well as free up some bhp for sure. :-) this will help in my quest of ultimate b16a.