LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently September 22, 2019, 9:04 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 373 posts ]  Go to page Previous  1 ... 21, 22, 23, 24, 25
Author Message
PostPosted: October 28, 2015, 11:54 am 
Offline

Joined: August 12, 2012, 6:38 pm
Posts: 1935
Location: worcester county, Massachsetts
LateralScience wrote:



Also, the closer the outboard shock pickup point is to the lower spherical bearing, the lower the bending moment. (The worst is applying bending loads 90 degrees midspan of the LCA.)


Sure is. I did the same on the LCAs for the B-3. bottom shock eye is within 2 inches of the bottom trunnion pivot. Also why I used .083 wall 1 inch DOM. turns out - from my not-quite-destructive test bash into that granite curb last may - the B-3 LCAs are stronger than the Spherical rod ends. so yay!

Carguy, stop it, you're making me blush...in a really awkward and uncomfortable way.

_________________
The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941

The Jag Special Build Log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=19012


Top
 Profile  
Reply with quote  
PostPosted: October 28, 2015, 11:55 am 
Offline
User avatar

Joined: May 2, 2009, 1:03 pm
Posts: 1392
Location: The Humid State of North Carolina
mjalaly wrote:
.... mine with 350whp is starting to not feel fast.
The first step to recovery is admitting you have a problem. Help is only a forum post away!!!

This is the statement that scares me the most about building this car. :shock:

K "speed addict" S

_________________
Check out Firearm Finishes & Coating for options to ceramic coat your Locost parts. Hundreds of stock or custom colors including Chrome and Clear Coating options now available! High Temp options for hot bits!! Plastics too!!

Never become a pessimist. A pessimist is correct oftener than an optimist, but an optimist has more fun, and neither can stop the march of events.-Robert A. Heinlein


Top
 Profile  
Reply with quote  
PostPosted: October 28, 2015, 8:02 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
botbasher wrote:
mjalaly wrote:
.... mine with 350whp is starting to not feel fast.
The first step to recovery is admitting you have a problem. Help is only a forum post away!!!

This is the statement that scares me the most about building this car. :shock:

K "speed addict" S


I think mjalaly is kidding...right? 350 hp in 1200 lbs is already in the 3 lb/hp range--which is insanely fast. I did pick up an Eaton M90 supercharger for when more torque is needed. I plan on working out all of the bugs first with the chassis and suspension/tires/ brake balance, and gradually learn the car first. Perhaps I'm just old and boring. My past exerience with high hp turbo cars for autocross is the non linearity of the power delivery makes it a handful. The B series engine is already very peaky to begin with. Where it needs torque is 2000-5000 rpm at corner exit in second gear.

I currently do alot of engine development engineering work in south Texas on light duty platforms on engine Dynos. No doubt it's very easy to make power with a turbo, but extended steady state running at high perturbine temperatures and pressures, is often very taxing on cyclical thermal fatigue on the manifold and bolted flanges. Additional thermal loads are sent to the oil, and exponentially degrades the oil. The new downsized turbo GDI engines running 20 bar BMEP can do so very reliably with DI and upwards of 1.4 equivalence ratio and adaptive knock sensors to retard CA50 timing, all while still maintaining impressive BSFC at part load. I hate to say it, but our B series engines are rather antiquated both in terms of knock tolerance and volumetric efficiency.

I think if I was to do this again the future, I would go with a motorcycle engine due to the lack of weight, an H2R engine would be amazing, that or an BMW V10 engine simply because of the smoothness and sound. Or a GDI Mazdaspeed 3 engine with 280 ft lbs of torque.


But at the end of the day I need to keep it simple and be reasonable with the car, and make do with what I have, and make the car function as one cohesive unit.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: October 29, 2015, 12:29 pm 
Offline
User avatar

Joined: October 13, 2011, 9:19 am
Posts: 1308
Location: Denver Co
Quote:
I think mjalaly is kidding...right? 350 hp in 1200 lbs is already in the 3 lb/hp range--which is insanely fast.


I was kid of kidding. I too drove my car slow and steady then i drove the crap out of it! Hard for lots of different issues to show up until you do ; )

FYI, it makes autox all the better... power sliding and wiping out cones rules. The turbo is awesome on the road course it just takes a bit to learn, which i am still figuring out.

Quote:
I currently do alot of engine development engineering work in south Texas on light duty platforms on engine Dynos. No doubt it's very easy to make power with a turbo, but extended steady state running at high perturbine temperatures and pressures, is often very taxing on cyclical thermal fatigue on the manifold and bolted flanges. Additional thermal loads are sent to the oil, and exponentially degrades the oil. The new downsized turbo GDI engines running 20 bar BMEP can do so very reliably with DI and upwards of 1.4 equivalence ratio and adaptive knock sensors to retard CA50 timing, all while still maintaining impressive BSFC at part load. I hate to say it, but our B series engines are rather antiquated both in terms of knock tolerance and volumetric efficiency.


Not sure if your name is brad but...

https://www.youtube.com/watch?v=Hrm-rPSCIBw

that's why you use ARP hardware and an oil cooler! And that all goes away once they optimize the electric turbos in development right now. No argument on the VE though.

_________________
My build: http://www.locostusa.com/forums/viewtop ... 18&t=13096


You can build the most awesome thing in the world but at some point, an 80yr old man in a crx is probably going kick your butt on the track... don't ask me how I know.


Top
 Profile  
Reply with quote  
PostPosted: October 29, 2015, 6:57 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
My apologies mjalaly, I didn't intend on coming off like a dick. You know I think very highly of your fabrication skills and car. I just try to explain my reasoning as most accurately as I can. You are correct in that an oil cooler will help, but reduces the bulk temperature of the oil in the sump and engine. The oil returning from the turbocharger will have a local temperature easily in excess of 800 to 900 deg C. Essentially the oil is thermally tortured at the turbo. The high temperature fasteners certainly help, however I'm referring to the flanges themselves. I've seen numerous issues with Tial 38mm WG flanges retaining clamping loads at elevated preturbine temps.


And yes, good catch on the inboard suspension tabs, as you are correct. Peak stresses will be higher in my current orientation instead of loading in only tension or compression. I suppose I just made a bunch of tabs and spent forever measuring placement. The 3/16" thick tab on a 1.75" 0.095" wall 4130 tube capturing a 1/2-20 heat treated socket head screw loaded in double shear should prove to be sufficient still. I believe my excel calcs showed a FOS in the hundreds.


In regards to the exhaust placement, I'd rather not add more weight to the rear, let alone above the engine. As much forward placement of remaining components the better. Plus I'm trying to stay more vintage Locost7 style, and less Mad-Max meets a formula car. Also, my throttle body will be where you've got your exhaust.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: October 29, 2015, 8:04 pm 
Offline
User avatar

Joined: October 13, 2011, 9:19 am
Posts: 1308
Location: Denver Co
Never said you were being a dick, more impressed than anything... I have just been dying to use that video for a while.

I will also keep and eye on my f38 as you noted.

_________________
My build: http://www.locostusa.com/forums/viewtop ... 18&t=13096


You can build the most awesome thing in the world but at some point, an 80yr old man in a crx is probably going kick your butt on the track... don't ask me how I know.


Top
 Profile  
Reply with quote  
PostPosted: February 19, 2016, 8:23 pm 
Offline

Joined: April 14, 2010, 8:36 am
Posts: 28
Very cool build. This is the first I've ventured into the non-traditional build logs and now I'm disappointed I haven't looked over here sooner.

It's also cool to see someone else who works in engine development. Some odd similarities, I also grew up as a Honda gear head and know D & B series engines inside and out. Now I work on huge industrial engines that have a very different duty cycle (natural gas though, not diesel). I was actually just down your way for an installation of 6x ~9MW units. Just between Houston and San Antonio.

Maybe it's just that I read it straight through but you hit the engineering buzz words an awful lot, haha. I felt like starting a counter for "double shear" at one point.

Just giving you a little crap but an absolutely beautiful build you have. You should be very proud!

LateralScience wrote:
The oil returning from the turbocharger will have a local temperature easily in excess of 800 to 900 deg C.


Those numbers seem a bit high. Liquid oil doesn't really exist at those temperatures. I typically start to see a lot of polymerization/coking at about 750F with even short exposure. Check out a distillation curve of oil for reference.

_________________
Haynes/Saturn F20C Build Log: http://locostusa.com/forums/viewtopic.php?f=35&t=17008


Top
 Profile  
Reply with quote  
PostPosted: March 16, 2016, 10:10 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Still at it Gents. However I lifted the head on my daily driver/grocery getter, thus priorities changes over the winter. I rebuilt the VQ35 in the infiniti, thus resources were temorarily reallocated away from the toy car.

So while the toy car was on pause, I pulled the engine out of the Infiniti G35:
Attachment:
pulled engine.jpg
pulled engine.jpg [ 1.01 MiB | Viewed 3633 times ]


On the stand, (note project car sadly sidelined):
Attachment:
Engine out of G35.jpg
Engine out of G35.jpg [ 1.06 MiB | Viewed 3633 times ]


Three months pass, during which forged pistons and rods were added, along with ARP L19s, Tomei cams, and JWT valve springs:
Attachment:
checking piston to wall clearance.jpg
checking piston to wall clearance.jpg [ 827.69 KiB | Viewed 3633 times ]


OEM vs Wiesco and Eagle:
Attachment:
OEM vs. WeiscoandEagle.jpg
OEM vs. WeiscoandEagle.jpg [ 1.14 MiB | Viewed 3633 times ]


Heads back from Duffin Engine Machine Shop:
Attachment:
VQ35 heads.jpg
VQ35 heads.jpg [ 1.39 MiB | Viewed 3633 times ]


Very smooth rotating assembly:
Attachment:
11to1 overbored CR Weisco pistons.jpg
11to1 overbored CR Weisco pistons.jpg [ 963.24 KiB | Viewed 3633 times ]


The engine is back in the car, and the increase in compression ratio, displacement, and intake cam lift and duration is rather intoxicating. The engine runs 1.3 equivalence ratio on the torque curve, and with the 68 deg C Mishimoto thermostat I'm pretty far away from knock, although combustion efficiency likely suffers. But good god I can spin 3rd gear easily with the heat-cycled-out RS3s. Thus, she was shod with new shoes:
Attachment:
shod with 255-35-R18 RS3s.jpg
shod with 255-35-R18 RS3s.jpg [ 769.26 KiB | Viewed 3633 times ]



In regards to resuming work on the mid engine locost7, I'll need a few weeks to allow accounts to recover from the engine build--but I am still at it. I'm working on routing the 1.5" aluminum coolant tubes going from the rear of the car to the front radiator, all while trying to ensure the passengers legs won't get burned via conduction through the floor.

But my god, there is still so much left to do:
-coolant tubes
-brake master cylinders
-clutch master and slave cylinders
-brake and clutch lines
-throttle cable
-fuel pump
-fuel lines
-ECU harness
-Caterham body panel order/fitment
-chassis and body paint
-headlights and mounts
-turn signals, brake, backup lights and mounts

Still so much work to do, and considering my work at the office is spooling-up something fierce, this makes it rather difficult to find the time to make progress on the car if I have 10 hour days at the office.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: March 17, 2016, 1:07 am 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
rsmith2786 wrote:
Very cool build. This is the first I've ventured into the non-traditional build logs and now I'm disappointed I haven't looked over here sooner.

It's also cool to see someone else who works in engine development. Some odd similarities, I also grew up as a Honda gear head and know D & B series engines inside and out. Now I work on huge industrial engines that have a very different duty cycle (natural gas though, not diesel). I was actually just down your way for an installation of 6x ~9MW units. Just between Houston and San Antonio.

Maybe it's just that I read it straight through but you hit the engineering buzz words an awful lot, haha. I felt like starting a counter for "double shear" at one point.

Just giving you a little crap but an absolutely beautiful build you have. You should be very proud!

LateralScience wrote:
The oil returning from the turbocharger will have a local temperature easily in excess of 800 to 900 deg C.


Those numbers seem a bit high. Liquid oil doesn't really exist at those temperatures. I typically start to see a lot of polymerization/coking at about 750F with even short exposure. Check out a distillation curve of oil for reference.


Thanks for the kind words and feedback. Double shear was drilled into us in FSAE and ME design, as we should think of single shear as also inducing a bending moment. As per the 800 to 900 deg C temperatures, perhaps I should have been more concise; I have measured 800~900 deg C pre turbine exhaust port gas temps with k type thermocouples in my lab. A glowing bright orange-yellow turbine housing has a very shallow thermal gradient across the assembly, and local temperatures of the oil at the turbine housing is nearly at the same temps as the housing. As for the phase state and chemical composition of the oil after such exposure, you're more knowledgeable than this old numbskull.

Nevertheless, it is amazing these small boosted and downsized ~22 bar BMEP 1.4L engines can survive, but generally at 1.2~1.4 phi to reduce pre turbine temps.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: March 17, 2016, 8:39 am 
Offline
User avatar

Joined: October 13, 2011, 9:19 am
Posts: 1308
Location: Denver Co
You know they make a bolt on supercharger for the infinity right? :lol:

I have the same infinity (2008?) and it might make you disappointed in your race car once you able to drive it like i was. You have to go really really fast or be on some super turney roads to get the same feeling as you do in the infinity... the "i am on rails and i am going to loose it at any second" feeling.

Its more fun to drive a slow car fast than a fast car slow.

Looking for more on the build!

_________________
My build: http://www.locostusa.com/forums/viewtop ... 18&t=13096


You can build the most awesome thing in the world but at some point, an 80yr old man in a crx is probably going kick your butt on the track... don't ask me how I know.


Top
 Profile  
Reply with quote  
PostPosted: March 17, 2016, 10:46 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
mjalaly wrote:
You know they make a bolt on supercharger for the infinity right? :lol:

Looking for more on the build!


Bolting a supercharger on an overheating engine with a blown head gasket...yeah, that's a great idea! Jk. I'm aware of the vortec and stillen blowers, but an aftermarket hood would be needed for the stillen, and the vortec is a fair bit of coin. I'm not planing anything crazy for the G35, as I really intend it to be just a fun daily driver to beat on. It's still a slow ~5 second 0-60 car, as she's a big girl at 3300 lbs.

I haven't given up on the middy locost7, and work will resume when parts and time becomes available.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: March 18, 2016, 6:54 am 
Offline

Joined: August 11, 2012, 4:44 pm
Posts: 1423
Location: Charlotte, NC
Please put long tube headers on the G. They engine sounds so good with a good header and exhaust especially with the mods you have done.

_________________
30 years old, not sure what I want to be when I grow up…


Top
 Profile  
Reply with quote  
PostPosted: March 6, 2017, 4:25 pm 
Offline

Joined: February 12, 2017, 7:57 pm
Posts: 42
This is a fantastic build. Any updates?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 373 posts ]  Go to page Previous  1 ... 21, 22, 23, 24, 25

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY