[doug2507]

Welcome. You will find some of the best in the world here. People capable of getting as technical as you can "imagine". I remember when you first started posting I got the impression that you are pointed and knowledgeable. I have read back and forth on this site and was wondering where you came from? Now I have a better idea. Thank you for your contributions and look forward to more of what you got. Speaking of gotovato he needs better hubs. Might you share if those can be had for him, they look aftermarket and he's made a waste land out of hubs.. I had to comment to get you in my stream. I will say if your planning on boosting the drive train out of your Wifes new car. This would be of great interest to me. I must know how that goes for you.

I use OEM hubs, NTN bearings (Front) and longer studs.

Toungue and cheek remark about the CRV drive train, it'll definitely be staying the the CRV.

 

[LotusElise]

Never expected her to go with a Honda, she was keen on an AMG but test drives can easily change a person's mind!

Now I am curious, what was here experience on both and what specific AMG it was, which lost against a Honda CRV.

 

[doug2507]

A line Markus, G was a bit out of reach. 😅

 

[LotusElise]

A line Markus, G was a bit out of reach. 😅

Ah, good you didn't. The M133 engine and it successors are no easy engines for maintenance and cost to run it. Especially the turbo does seems to be a princess on the M133 versions, the M139 is still new, we will see how that princess comes out. I wonder how long the CAT survives on these engines.

In German, but think about, your wiifi would have drifted on the way to the grocery, for sure .

 

[doug2507]

Ok, so moving on....brakes....

UK hillclimb is rather niche is a sense. All tracks are mostly on private ground which is completely different to the Euro stuff. Runs are relatively short, anything from around 30 seconds to a little over a minute. We don't need monster callipers / discs to cope with heat so the only real focus is having enough breaking force to stop the car from cold.

Quite some time ago i got in touch with AP for spec'ing brakes. I was totally oblivious at the time to what was required to do this properly and thought if i gave them a rough chassis weight / split and application they'd sort me out there and then. For those that don't know, there's far more to it to do this properly than you'd think. Static weight, dynamic weight, brake pad / tyre coefficients, tyre force, CG etc etc, best guess doesn't cut it.

At the time of getting in touch with AP i had stock rear callipers and Stoptech Trophy front BBK. Unfortunately i learned the hard way that a BBK on the front without any bias correction is a big no no and that's what put the car back on axle stands after finding out how easy it is to 180deg when stomping on the anchors. Getting all the correct measurements to spec the brakes at the time wasn't possible so i spoke to a brake specialist and had a set of front / rear brakes made based on expected weight / distribution.

The sexy Stoptechs that did nothing good....

And the replacements....

Criteria given to my brake guy was enough stopping power for a given weight / distribution whilst being mindful of unsprung weight. Handbrake isn't required by reg's for my class so there was a little more freedom with the rears than usual. Setup i've got now consists of Willwood calipers / discs / pads on all four corners and significantly reduced weight on each corner as well. Front is running Midlite calipers with 279*20 discs, rear's are 260x19mm discs with Powerlite calipers, BP10 pads all round. Custom bells were made for the fronts and all 4 corners have carriers machined to suit.

All of this was done pre COVID and the car's not been out since so it's all still to be proven!

This year i decided to pull the finger out and get it back on track for next year, with that decision has come a few intended modifications to get the car to where i want it as an end goal and leave very little on the table for future modifications other than seat time and setup. One of those changes is a serious focus on weight distribution / CG and that means moving my ass further back in the car. To do so means alteration to the steering column to extend it and also relocation of the pedals. Obviously that can't realistically be done with the OE pedal arrangement so i decided on an entry level AP pedal box (very relative, entry AP pedal box costs more than most others mid tier pedal boxes!). I spoke with the dealer about MC sizing and we both had similar thoughts so order was placed and this arrived a few days later......

Initially supplied for cable but i was keen to take advantage of the engine rebuild and move to DBW for various reasons so sensor is also sat on the shelf ready to go.

Despite all good intentions, when the car's rebuilt the braking system will be subject to change. I'm taking things seriously now rather than a go with the flow mentality so once i'm able to take all applicable measurements the system will be reviewed / revised and we can spec it specifically for the car. Might even be able to reduce weight further!

In my last post i talked about suspension. Confirmation of spec has been reached and ill be running DC5 rear hubs on EP3 knuckles (+15mm track width vs EP3), bespoke front arms whilst retaining EP3 knuckles rather than DC5 knuckles (lighter than DC5 knuckles and +55mm max track either side through the arms). The PCI stuff will be sold but i'll be retaining Brians front ARB. Existing front brake carriers will still be good but i'll need to send a rear knuckle / DC5 hub to my brake guy to machine new carriers for the rear. Wheel offset and width / tyre size to be discussed with my race engineer and that needs to happen sooner rather than later so i can start making molds for the wings / arches / fenders (call them what you want!). Weight / CG / Track width, all 3 boxes are being ticked.

Next up, gearbox, then onto the engine....

 

[Lotus]

A friend updated his JRSC K20 Elise last year with a dual MC balance bar set-up.
He is very happy with the track performance as now bias can be dialed in to max stopping power without overbreaking the rear. Before he could only change disk sizes and pad compounds. This is much nicer to dial in.

 

[doug2507]

Indeed, from what i can gather once the rest of the system is spec'd accordingly then it should be a winner. I've read lots of comments about people trying to use a pedal box and resorting back to stock due to issues sizing MC etc. Doing it the mathematical way rather than best guess hopefully will produce the required result. I know there's a split opinion on various topics regarding theory vs reality but pinnacle motorsport teams don't employ engineers "just because". Once the car's rebuilt, all measurements required will be taken then the system reviewed accordingly. I'll run sensors for bias so we'll be able to dial in braking through the data logs.

Off topic, i hate having conversations with people on a subject i largely know nothing about. I'm the type of person that want's to know the subject matter to make my own informed decisions and not be glossed over by a salesman selling ice to eskimos. Last week i enrolled myself on a Mech.Eng Higher National Certificate to get the ball rolling. It helps with my job but the real motivation is this. End goal is to get BEng/Masters then jump into a motorsports degree. Knowledge=fast lap times!

 

[doug2507]

Drivetrain...

Plenty of options available for the K20. stock, OE LSD, MFactory kits, multitude of LSD's, FD options etc. I happened to to be in the right place at the right time a few years ago and bought a PPG 5 speed box from an ex drag racer which was fitted with a 4.3FD and quaife ATB. It had done 6 passes at Santa Pod (main UK 1/4 mile), dyno time and that's it. When it came into my ownership i changed the FD to a 5.83, sold off the ATB and installed an OS Giken spec X LSD. After a few conversations with the USA division of OS Giken the diff was set as per the honda works cars and fitted to the box.

Driving a dogbox was new to me. Making sure revs were matched to prevent kangerooing was foremost in my mind and i felt this distracted me from concentrating on braking / turn / accel. As you can probably tell by now, i've jumped in head first so i'm willing to accept any opportunity to make life easier when feasible. There's a few cars in my class that now run sequential boxes, the difference these make is absurdly apparent. On throttle accel through the gears is undeniably quicker than a std H pattern but there's also more perks to life than just that.

Changing to seq is a substantial investment, these boxes aren't cheap. You've got Quaife, Sadev, Beckert, XTrac etc, not one of them is an easy purchase for an amateur like myself. I've kept my eye on the classifieds for a few years tbh but most (especially Sadev) are bogus adverts. You've got to be really careful when perusing a deal, lot's of scammers about for stuff like this.

When i found out the engine needed a rebuild, i made the decision to invest in a sequential box. The remit was / is to build the car to the highest spec i can (within budget) within the regs.

Quaife was top of the list, mostly due to retaining the original casing (OE mounts) and i could keep the Giken diff. S/H unfortunately was always the wrong ratios or the wrong FD, new price was steep compared to the alternatives and ratios weren't ideal. I've been in touch with Sadev for a few years now and prices have gone up. They do offer a good package but price is at a premium now after Brexit. Xtrac i never looked into TBH but i already had a box in mind...

Over here in the UK there's a company called Satchell Engineering. Colin Satchell (owner) competes in the same class with a Peugeot 205 and has set many records. He's done remarkably well to the extent of getting an invite into the Hillclimb Masters a few years ago (go search on YT for vids). Not only has he designed a great car, he has an eye for quality products. Satchell happen to be the sole UK distributer for Beckert boxes so my ears were peaked. After a little further research, i decided that ratios would suit the application, i could get a 6 speed rather than a 5, the LSD was well proven / fully adjustable & reliability through various applications (Area Motorsport used this box in their circuit endurance build, Colin hillclimbing and various others with rally) was also proven. I had to dig deep but after a few weeks this arrived...

Beckert Evo 1 seq box. This is running their own LSD spec'd for hillclimb and Honda F2 homologated ratios. Top speed will be circa 130mph which i won't see on a UK hillclimb but it leaves the door open to other things, 1-5 is where all the action will be but having 6th won't be a bad thing and box weight of 5spd vs 6spd is insignificant. What matters the most is the gearing. With expected peak HP/TQ of the new engine it'll synchronise with the HP/TQ band nicely and keep the K20 "on the boil" as we say over here. They offer a few different ratios but i decided the Honda F2 ratios would suit best. I could state ratios but you can look this up yourself, it's all relevant to max rpm and that's not something i'll disclose at this point in time but it'll be circa 9.8krpm+. Box weight is 39kg IIRC but i've still to weigh it to confirm.

Downside is it needs bespoke mounts. Both the side mount and rear mount need to be fabricated. The rear is the easy job, it's basically a bushed turnbuckle that needs a mounting point welded to the subframe, the side mount is a little more complex and potentially involves chassis arm modification. The chassis is away to my fabricator next week for a small list of jobs to do and this will be one of them, we'll have a look at it together and decide the best course of action.

Beckert stipulate that all mounts (engine and box) use the same shore rating but after a chat with Satchell, this was really aimed at those who tried to solid mount one area (box side) and ran into issues. The rear turnbuckle and box mounts will fabricated to using Superpro inserts and the engine mount will be innovative 85a. I need to confirm the shore rating of the Superpro bushes but think we'll be good. This one might have to be proven by application rather than best endeavour.

Further to that, driveshafts are bespoke. Once the box is mounted i need to wait for the engine to be built / fitted and all suspension in place to measure for driveshaft length. One step forwards and two steps back in a way.

To make best use out of drivetrain and engine, i've decided to change to DBW. Having already had Kinslers, they were the 1st thought. Converting cable Kinslers to DBW isn't feasible and the new engine will most likely require a set of ITB's that use a smaller ID than Kinsler provide (57mm) and we may take advantage of different inj. position. This is all still TBD pending flow data of the head that will be used but it's highly likely that a set of Jenveys will be fitted. Either way, i decided to go for paddle shift vs stick and eliminate the clutch completely apart from getting off the line. There are a couple of options available on the market but Geartronics won the day. Geartronics has been proven for years, most seq setups here in the UK use them and already having the system controlled by Motec, the decision was a no brainer. Motec offer 3 different packages, GPA, GPR & GPRP, the latter being for paddle shift. Neil@Geartronics teamed up with RDS (Race Data Systems) and basically created their own GPRP package but with far better control. Paddles weigh less than a stick, i can keep both hands on the wheel and the software control is above what Motec can offer - Win win. Always remember, weight means everything...

Additionally, the AIM MXS (Link) Strada dash i had has been sold and i'll be using a Geartronics dash. It less cluttered than the Aim dash, gear position is primary with selectable secondaries, all data logging will be through the M130 which now has Lvl.3 logging enabled (1000hz) and it weighs less. Did i mention weight is key?

Beer coaster vs size of dash...

Clutch & flywheel are probably relevant to this now so i'll mention them as well. The Beckert box uses a Ford spline rather than Honda so a clutch change was required anyway. Previous was an Exedy stage 2(?) 3 puck sprung clutch plate with matching diaphragm combined with an Exedy Race flywheel. Total weight of this setup was over 9kg IIRC. I approached TTV over here in the UK and set out the criteria for clutch / FW spec. After a few conversations, measurements were taken (mostly relative to crank face, bolt height) and we agreed on a suitable setup. FW is their K20 race FW for a 140mm clutch which centralises mass (2.7KG total) and clutch is a 140mm twin plate paddle coming in at 1.89kg. 184mm was initially offered but i'd rather rather have reduced inertia even if the twin 140mm far exceeds the TQ rating of what the engine will be capable of producing. I don't pay lip service to inertia, it has pro's and con's but i'm in the mindset of i will learn to drive it correctly and i'd rather take the mechanical advantage and be forced to deal with it than take the easier route and sacrifice inertia for lack of driver ability.

Next topic is most likely engine and that's a whole other can of worms....

 

[yaggs]

This thread is amazing. Thank you for the detailed posts. Keep up that great work!

 

[MoHo]

Next topic is most likely engine and that's a whole other can of worms....

I welcome you and all your doing this is a serious car your building. Way beyond me but neat to see what the other half drives.

 

[LotusElise]

Knowledge=fast lap times!

Indeed, I would add realization of it, as I sometimes have a challenging time to find just the parts and built quality needed for the realization of that knowledge. Budget is not the only constrain, market or fabrication availability and timing is often also a constrain here. But sure knowledge is the basis for all the fab and buy action.

GB has concentrated a lot of racing schools and University courses as well as teams of a very high level and experience. That is an location advantage you have. I wanted to study combustion engines at the TU Munich, but that time there was even no Prof. active on the chair of ICE (headquarter of BMW). Anyway, I've decided to study the basics, thermodynamics and fluiddynamics as well as a lot of practical modeling and simulation as well as test rig development and measurement. I've gathered then further 9 years on an engine OE, which was quite helpfully and valuable.

I had a long way through study, doctorate, OE experience and still didn't know nothing about race engine design. Of course all the way helped me to understand every detail and enabled me to dive deep into all of them, but I think a shorter way should be possible. If I were in your situation, I would go top down, from system to as much details as possible, but always having the system as focus. Everything begin there, understanding details without that is useless, but it is a way of experience coming from top down to understand all the details.

FW is their K20 race FW for a 140mm clutch which centralises mass (2.7KG total) and clutch is a 140mm twin plate paddle coming in at 1.89kg.

Sounds like a progress, making the speed dynamic much more sensitive, which is good on a NA engine of 300+ hp and the need grip as well with your shift system. Durability will suffer, but racing is a compromise .

 

[doug2507]

Absolutely Markus, knowledge is only half the battle. If I can utilise my spare time more effectively to achieve a better understanding of how each system works, then I can make better informed decisions myself rather than be solely reliant on what someone else is telling me. I'm in a fortunate position where hobby and work crossover to some extent so the benefit and motivation to do so is easy to see. Ploughing my way through all the maths stuff right now which is reasonably enjoyable in itself but looking forward to the more interesting stuff like thermo & fluid dynamics.


If the car was still going to run on cable and H pattern then I don't think I would have chosen a FW/Clutch setup of this weight, I think it would end up being quite a difficult car to drive. Changing to seq/dbw has opened the door for reducing inertia in this area IMO but I'll need to wait and see how it runs when back out. TQ rating of the clutch far exceeds the box and expected output but lifespan / fatifue and holding capacity are two totally different things I would think, it'll be interesting to see the wear on the plates after a full season...

 

[MoHo]

it'll be interesting to see the wear on the plates after a full season...

That EXCEDY didn't seem to beat up. I will be watching this even if I can't afford a bit of it. I'll try to spend my 2 cents elsewhere as not to interrupt.

 

[gotovato]

Ok, so moving on....brakes....

UK hillclimb is rather niche is a sense. All tracks are mostly on private ground which is completely different to the Euro stuff. Runs are relatively short, anything from around 30 seconds to a little over a minute. We don't need monster callipers / discs to cope with heat so the only real focus is having enough breaking force to stop the car from cold.

Quite some time ago i got in touch with AP for spec'ing brakes. I was totally oblivious at the time to what was required to do this properly and thought if i gave them a rough chassis weight / split and application they'd sort me out there and then. For those that don't know, there's far more to it to do this properly than you'd think. Static weight, dynamic weight, brake pad / tyre coefficients, tyre force, CG etc etc, best guess doesn't cut it.

At the time of getting in touch with AP i had stock rear callipers and Stoptech Trophy front BBK. Unfortunately i learned the hard way that a BBK on the front without any bias correction is a big no no and that's what put the car back on axle stands after finding out how easy it is to 180deg when stomping on the anchors. Getting all the correct measurements to spec the brakes at the time wasn't possible so i spoke to a brake specialist and had a set of front / rear brakes made based on expected weight / distribution.

The sexy Stoptechs that did nothing good....

View attachment 114698

And the replacements....

View attachment 114699

View attachment 114700

View attachment 114701

Criteria given to my brake guy was enough stopping power for a given weight / distribution whilst being mindful of unsprung weight. Handbrake isn't required by reg's for my class so there was a little more freedom with the rears than usual. Setup i've got now consists of Willwood calipers / discs / pads on all four corners and significantly reduced weight on each corner as well. Front is running Midlite calipers with 279*20 discs, rear's are 260x19mm discs with Powerlite calipers, BP10 pads all round. Custom bells were made for the fronts and all 4 corners have carriers machined to suit.

All of this was done pre COVID and the car's not been out since so it's all still to be proven!

This year i decided to pull the finger out and get it back on track for next year, with that decision has come a few intended modifications to get the car to where i want it as an end goal and leave very little on the table for future modifications other than seat time and setup. One of those changes is a serious focus on weight distribution / CG and that means moving my ass further back in the car. To do so means alteration to the steering column to extend it and also relocation of the pedals. Obviously that can't realistically be done with the OE pedal arrangement so i decided on an entry level AP pedal box (very relative, entry AP pedal box costs more than most others mid tier pedal boxes!). I spoke with the dealer about MC sizing and we both had similar thoughts so order was placed and this arrived a few days later......

View attachment 114702

Initially supplied for cable but i was keen to take advantage of the engine rebuild and move to DBW for various reasons so sensor is also sat on the shelf ready to go.

Despite all good intentions, when the car's rebuilt the braking system will be subject to change. I'm taking things seriously now rather than a go with the flow mentality so once i'm able to take all applicable measurements the system will be reviewed / revised and we can spec it specifically for the car. Might even be able to reduce weight further!

In my last post i talked about suspension. Confirmation of spec has been reached and ill be running DC5 rear hubs on EP3 knuckles (+15mm track width vs EP3), bespoke front arms whilst retaining EP3 knuckles rather than DC5 knuckles (lighter than DC5 knuckles and +55mm max track either side through the arms). The PCI stuff will be sold but i'll be retaining Brians front ARB. Existing front brake carriers will still be good but i'll need to send a rear knuckle / DC5 hub to my brake guy to machine new carriers for the rear. Wheel offset and width / tyre size to be discussed with my race engineer and that needs to happen sooner rather than later so i can start making molds for the wings / arches / fenders (call them what you want!). Weight / CG / Track width, all 3 boxes are being ticked.

Next up, gearbox, then onto the engine....

Almost nothing inspires driver confidence like a responsive and consistent brake pedal. So many focus on "BBK" regardless of brake bias, pedal feel, MC sizing, any of it! I can really appreciate your in depth approach here. Races can be won or lost all over the brakes!

I look forward to hearing how the new setup works for you. With the runs you do that little wilwood kit should be good. Your car is light as well which is awesome.

I know you're ditching the stoptech setup but i must say i have been more then happy/impressed with my stoptech C43 kit. Bias is perfect, rotor sizing is "smaller" compared to other kits but the setup really is effective and light weight.

Much of your build to me screams "unlimited time attack spec" and im loving it. We dont see many NA builds of this caliber around here. Now to catch up with your lastest post...

 

[doug2507]

That EXCEDY didn't seem to beat up. I will be watching this even if I can't afford a bit of it. I'll try to spend my 2 cents elsewhere as not to interrupt.

Very little use tbh, majority of its time was spent on the dyno. Very easy clutch to use and ideal for a K20, I think Tom / Gotovato has the same in his car (?).

One thing I didn't realise until the new setup had arrived and the box showed up is the requirement not to use a sprung clutch for the box. Ended up lucky in that regard as I wasn't aware that was a requirement until I read through some notes that came with the box!

 

[doug2507]

Almost nothing inspires driver confidence like a responsive and consistent brake pedal. So many focus on "BBK" regardless of brake bias, pedal feel, MC sizing, any of it! I can really appreciate your in depth approach here. Races can be won or lost all over the brakes!

I look forward to hearing how the new setup works for you. With the runs you do that little wilwood kit should be good. Your car is light as well which is awesome.

I know you're ditching the stoptech setup but i must say i have been more then happy/impressed with my stoptech C43 kit. Bias is perfect, rotor sizing is "smaller" compared to other kits but the setup really is effective and light weight.

Much of your build to me screams "unlimited time attack spec" and im loving it. We dont see many NA builds of this caliber around here. Now to catch up with your lastest post...

The Stoptech kit I thought was really well made, it was my own fault for not thinking that I'd need to change the bias vs stock. Easiest lessons learned seem to come the hard way! On the plus side, between wheel / tyre change and brakes, I think I dropped around 20kg unsprung weight between all four corners. I think I'll be able to run smaller rear calipers / 2 pot but only time will tell.

I get the reference to TA but obviously there's some major differences. Aero, cc, etc. Whole approach to the car now is to get it to a state I'm happy with that I don't have to revisit areas in the future. Do it right - do it once. Setup / seat time / fun is the only focus I want once it's back up and running. Engine will require frequent inspection intervals but that's all part of the game. Really looking forward to getting back in it and hopefully this time it'll be plain sailing rather than issues!

 

[gotovato]

I think Tom / Gotovato has the same in his car (?).

yes i am using the same exedy in my car. Its been fantastic and ill continue to run it for 2024

 

[gotovato]

I think I dropped around 20kg unsprung weight

this is really HUGE. Its awesome to see this much unsprung mass being deleted. i know i was thrilled that my stoptech kit saved me 15lbs per side up front. Quite a bit when dealing with NA power

Setup / seat time / fun is the only focus I want once it's back up and running.

this right here is how i ended up with my Honda. Chasing big turbo power got expensive and boring. Maybe i went backwards but my driving has improved probably ten fold. Ive said it before and ill say it again NOTHING will beat seat time(all things being equal anyways). Ive learned that myself over the last few seasons

 

[doug2507]

100% and I'm not naieve enough to not put importance on seat time. You can build a car to any level you wish but without seat time it's largely meaningless. This one might have a few bells and whistles but I'm under no illusion that seat time is needed. I'm fortunate enough to have the mentality to focus on beating PB's rather than the rest of the field. I certainly won't be the quickest out there for a while and I'm good with that. I'd rather keep focus on my own development (chassis and driver) than worry about position in class. I'm out to have have fun, learn to drive the car, get to know it, figure out how I can improve. The car will have the potential, it's the driver that will hold it back.

 

[gotovato]

100% and I'm not naieve enough to not put importance on seat time. You can build a car to any level you wish but without seat time it's largely meaningless. This one might have a few bells and whistles but I'm under no illusion that seat time is needed. I'm fortunate enough to have the mentality to focus on beating PB's rather than the rest of the field. I certainly won't be the quickest out there for a while and I'm good with that. I'd rather keep focus on my own development (chassis and driver) than worry about position in class. I'm out to have have fun, learn to drive the car, get to know it, figure out how I can improve. The car will have the potential, it's the driver that will hold it back.

You’ve summed it up rather well!
Seat time matters. Mentality matters. Tuning both your car and yourself matters!

My first ever track build was backwards focusing on power and not so much on seat time. As I’ve said few times now my world has been flipped in this sense and I’m loving it.

I probably spent more on seat time in 2022 then most spend on hard parts. I took my 163whp civic and absolutely went to town on extracting every 10th of lap time out of that car. Well worth the investment however it’s rather boring in the eyes of social media