V-12 Engine into 308 Build, over on Grassroots

I'd ask Paul Russell.

 

I just hate the idea of cutting more off rhe block to make my already sketchy liners work and am pretty seriously thinking about shimming the liners instead of cutting the block. The shims would be split, but there is no place for them to go so other than little to no o-ring compression so id be counting on the rtv more.

 

I finish up up the brake lines with the front transducer cut in and the lines bled.

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factory spec says 4" brake travel, 6.2" clutch travel, my setup is almost exactly reversed with 4" clutch and 6" on the brake, which moves about 2- 2.5" . No way to know how it feels now but mentally I believed I was feeling more flex in things making me sure the pressures are higher and it was totally worth the trouble.

I still need to wire in the new sensors. I was also looking a brake pads and found myself a bit confused. All 4 caliper and rotors are the same ans Stoptech list the sames pads f/r (for the f430 my brakes are from), but EBC lists different part number f/r with the prices at $80/$120....but I have no idea what is different or why I should pay the extra $40 instead of ordering 2 front sets. The pads I have look fine but I was thinking with higher friction would further improve the pedal feel so I was eying the EBC bluestuff as they don't offer green which looks like slightly higher friction I think just fine for my indended use. More thinking to do on that....I just hate the idea of spending $40 and not knowing why.

 

I figured out the front/rear pad thing. The site that had the best prices also had the numbers swapped so its the front pads that cost more and they cost more because they have wear sensors, which I don't have so I need to sets of the cheaper rear pads. . Then I have (ferrari) brembo calipers and there are absolutely green stuff pads that will fit these calipers but they don't show up on an F430 search because they F430 goes very fast and will easily overheat the green stuff pads.....bu green stuff pads are available for 308s and what I happily was running before the brake upgrade. So, green if I want the lowest pedal pressure around town, blue if I don't want to worry about overheat the brakes.

 

Decided on blue because the description on the green pads said there are 3 versions they match to the application so no way to know if I'm ordering an appropriate pad. The blue is probably the safer choice anyway since a 308 isn't a light car and mine isn't low hp so a little more pedal pressure around town to get brakes safe at speed seems a good trade.

 

The shim quote came, $150 so I guess if that is what I do I'll be making them myself.

Tonight I started on the transducer wiring and got the ECU end done. I think I've said before I use shielded tefzel wire for the sensors which means I can use the cool little shield terminators that solder themselves to the shielding and also moisture seal the wire.
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I started running the wires out to the sensors
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then remembered they come out here......and that is a tomorrow problem I think.
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I ordered the shim stock, I think it said delivers Saturday

Then moved on the finishing up wiring the transductors,. I still need to rezip tie stuff but they work so I moved on to adjusting all the new knobs on the brakes. It was a little more finicky than I was expected but after about 30 minutes the measured curve seemed to match the spread sheet numbers pretty well. I created a new tab in the ECU display for chassis data figuring I'll add GPS and steering at some point.
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This is maybe only interesting to me but I replotted the calculations with G force on the bottom and realized that the mechanical bias takes me to 0.5 g which is really all normal driving and it doesn't take a lot of pedal pressure to get to line pressures that should be 0.5g with the new pads. The 1st proportioning valve is 0.5-1.0g which is the limit of most street tires 2which is clearly why factories set up the brakes with 1 valve. The 2nd valve works 1.0-1.25G which is DOT race tires and the 3rd valve is 1.25-1.5 which is slicks and that is pushing friking hard on the pedal. The proportioning valves are throwing pedal force away and by 1.5G I'm losing about 25% if I'm doing the math right. It also kind of shows why when you get good tires all of a sudden the rear starts locking and the brake pad people offer lower friction rear pads to help sort it.
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The EBC Green stuff are mediocre, that was a good call to go for the Blue.

The Yellow stuff would take things down a notch (i.e. not great for track use but probably a bit better than the Blue stuff for the street)

 

I will never ever track this car so that's not a concern. Mostly I want to get the pedal force down so I feel more comfortable letting others drive it and that bought me to pad friction coefficients. Google says
Green=0.55
Blue=0.52
Yellow=0.42

That says pick green...but the ebc website says there are several green formulations tailored for the application, so no way to no what I would get. Blue is blue and its better at handling heat so even thought track time won't happen it is possible that to conceive thgat I or some unknow person would drive my car over the posted speed limit ro perhaps somewhere without a posted speed limit...and given the new gearing and increased redline puts theoretical top speed north of 200mph brake that can handle heat seemed a good option. Honestly the yellow stuff pads don't seem to have any reason to pick them

I still don't actually have the pads though. I order them from autohaus because they had the best price....but they aren't here yet. I got a note from the mail lady that she tried to deliver something today but a signature was required, that might be them.

 

The µ of the Green stuff drops significantly when they heat up, that's not something you want on a sports car.

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But there is more to brake pads than the friction coefficient. The overheated Green stuff will leave residues on your discs, causing vibrations.

The Blue aren't great when cold, hence why I suggested the Yellow stuff.

 

I'm pretty sure that graph is fabricated, I found it on a couple websites but I couldn't figure out where it came from. I'm certain it doesn't agree with the information on the EBC website or other sources. The old blue stuff (not sure they are still made) did have poor cold bite and were really a track pad but the current blue NDX which I bought have better cold bite, higher average u and less fade than yellow.

Prior to the whole V12 nonsense I've been on for the last many years now I had the green pads and stock brake system....they were fine. I honestly can't say that I actually noticed any change I can recall when I installed them and never had any issue with them because I don't do much high speed driving/braking. I autoX some and there are a few roads that follow creeks I like to drive so any hard driving I do is under 70-80mph. The bigger brakes are really just a cosmetic thing, I didn't like the way the stock stuff looked with the 18" wheels and have nothing to do with me thinking I had brake issue.

I did the dual master cylinder conversion fearing the new cams weren't going to give me good vacuum, which I'm not sure was right but its done now and the power brakes are gone so picking pads is mostly about getting the pedal force feeling better hence the focus on the pad cold friction numbers over most...ok, over all of the other factors. Clearly my particular details are a bit unique and other applications might might want a different pad.

Here is the EBC info for anyone who cares. I'm not sure how many of these will fit the stock brakes but all are available for the calipers I have. These options are all R90 approved for street use in Europe, not required here in the US but passing means they they have good cold bite and will act the way people expect brakes to act on the street.
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I just stumbled on the RP-X pads. Technically race pads but the specs including cold bite are really good. Maybe next set if I ever get the car running and have issues with brake fade.
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I don't see how you could have brake fade with the Blue stuff if you don't do spirited driving over 80 mph

 

Exactly, I'm thinking it'll be more than fine and my only concern is where the pedal force ends up. Years ago I had a '65 vette with manual brakes that was fine, nice even brake pedal force wise so I know it can be done and I'm hoping the new master cylinders and pads get me there.

 

Those stupid brake pads still aren't here and I still don't know when I might see head gaskets. I can get the mirrors back on anytime....I just need to get motivated.

I did finally figureout to to say no driving the ferrari in what seemed like the nicest possible way.
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Wow

Can I drive the Ferrari?

 

Mama said how about a civic? I countered that for a barely more a BRZ/GR86 seemed like something he'd like much better.....which somehow became a supra project car so we were watching Copart for the right opportunity and making plans to fit another project into the shop, which would mean moving the 308 aside for a bit and my already limited time directed to a new project. But then this one popped up for barely more than we planned as the project budget. It needs a few little things but the 308 can keep its shop spot and I won't feel bad in anyway saying no to handing over the 308 key so a win for me.

I do have a bit of a parking mess I need to sort out so my DD is on the grass at the moment.....

 

Update time.
The brake pads never arrived. The Last week I called/emailed a couple times and they sent a refund saying there was a production issue and it will be 10-12 weeks before the pads are available and they will email to let me know. They were the cheapest place and since the car doesn't run I've not tried ordering elsewhere. This is how the whole project goes though, even the simple stuff take way more time than it should.

I emailed the head gasket guy who I'd not heard from since Feb and after a couple days got a response asking for a little additional info. A buddy says the normal process is answer all questions then wait a LOT of days in silence for the call saying the gaskets are ready followed by happiness that the heads are sealed. So the wait continues.

Shame on me because I still haven't sent the trans adapter shaft out for heat treat or finished the shims much less install them nor put the side mirrors back together.....just plain lazy.

I did make the 2.5-3 hour drive down to the MD Toyota dealer a couple times to have a few things on the supra sorted. They were able to fix the right front camber issue by replacing the strut and steering knuckle costing me $1000 (they covered the $900 labor). Today its getting 4 new tires because the 2 fronts that looked great are missing the inside edges and the 2 new rears of a brand I didn't recognize are Amazon specials so another $1500 gone and since these are the OEM Michelin pilot super sports that are apparently unusable below 32F, another 1000-1200 come October for something that work in the cold. Now its not like they would have moved any more on price had I noticed any of this ahead of time but its still annoying. My son is not quite 17 in actual years, I think we're at about 28 in birthday present years.

Then the honey-do. I finally built a patio by the basement doors that has been on the list for a couple years now. I'm told garden boxes up this weekend......

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In the US, Michelin sells a great sporty all season tire that is the OEM tire for the C8 Corvette.

But I wouldn't say the PSS don't work below 32°F

 

I was just going by the blurb on tirerack

The 4S they get more specific and makes me thing the rubber is hitting the glass transition temp and becoming non-elastic.

The first car we test drove had the pss on and it was around 45F and damp roads but not raining....it was a challenge to keep the back in back, fun, but a challenge. Today its 70F and dry and it drove really nice, pretty hard to make it misbehave. The tires on the 308 are Sumitomo HTR summer tire Iiirc, because I wasn't sure the sizes I picked would fit and didn't want to spend a lot. On warm days they were great and I brought home a couple class wins at the autoX, but on a 60F morning they were pretty slick.. That was my only real complaint, it had to be t-shirt warm for them to work, no autoX on a cool day. Anyway, come fall I expect to pull those tires and find something with more tread and rubber that stays soft so teenager stays as safe as possible.

308 wise I know what will fit now and those Sumitomos have been sitting in the shop for 18ish years while I thought about a new ECU and blower then started the V12 debacle, and well, they make nice burnout videos now. I am about 1/2 shopping for new tires and do need to be certain I do not lose to the supra at the autoX, that would honestly be too embarrassing to bare. I don't drive it in the rain because it leaks and is generally unpleasant and even when it was ONLY 500hp was a handful. So I'm thinking 200 treadwear to be street class legal so son can't call foul, like maybe Yokohama Advan A052 or similar.....but first it needs to run so I can justify the purchase.

 

Have you considered the Pilot Sport Cup 2 connect? It has a 240 rating and offers data acquisition for cheap.

 

I'm honestly not sure what to do. Over the weekend I looked through the current SCCA autoX rules and it looks like I have 2 options.

SSM (super street modified), min weight 3015lb, DOT race tires
XB (extreme street B), min weight 2330, DOT 200tw tire

Weight wise, SSM is almost certainly where the car belongs. I've not weighed it but I can't imagine I'm under 3000lbs. But its only sort of a street tire class these days and something a Pirelli P Zero Trofeo R with its 60tw rating or maybe TOYO PROXES R888R with 100tw and is DOT but tirerack lists it as competition only and oddly in their testing was not all that fast. Those are soft tires. And then there is the Hoosier Racing Tire Sports Car DOT Radial R7.....which has a DOT marking but they say "WARNING: DOT labeled Hoosier Racing Tires meet Department of Transportation requirements for marking and performance only and are NOT INTENDED FOR HIGHWAY USE. It is unsafe to operate any Hoosier Racing Tire, including DOT tires, on public roads. The prohibited use of Hoosier Racing Tires on public roadways may result in loss of traction, unexpected loss of vehicle control, or sudden loss of tire pressure, resulting in a vehicle crash and possible injury or death."


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If I try XB then I'm told the right tires are Bridgestone Re71Rs, Flaken RT660, Yoko A052. They are more streetable tread designs and a 200tw....but I am WAY over weight in this class.

I know the right thing to do is install proper street tires....but when I race I like to be racing to win and I did just spent a lot of time making sure the braking system would work correctly with race tires......

 

Pilot Sport Cup 2 R, then? Their threadwear is below 200 but they're still actually useable on the road.

And if you don't win, you can blame the tire

 

Nothing even close to my sizes, 19" dai wheel min.

Edit: Same issue with cup2 and cup2r

 

A052s offer good grip - they seem to like high camber setups, but they turn into slicks within 1500 miles of street use only. I do not trust them in wet conditions, even less so when there is not much thread left.

Overall: It's a good product, I'll keep buying (unless i stumble upon something better).