ecotec swap

Hotrodz of Dallas wrote:We use Carbotech pads exclusively on our race cars. Amazing pads and customer service is great.
Prices are lower than what we were paying for Performance Friction and Pagid. But yeah, good pads aren't cheap.

Interesting. I've been a PAGID guy for years, (over 15?). I'm sort of at the point where I know there are better pads out there, but I'm so familiar with how they behave on track, I know exactly what to expect and how they wear. Changing from that is scary, especially barreling down the back straight into a right hander with a tire wall on the outside!

I talked to carbotech about the type of racing we do. They were very helpful in getting us the correct compound for our needs. We are using the XP12's front and rear. It's a 2000 Porsche 996 that we race in NASA and PCA. Under 3000lbs with driver. My driver liked the PFC's as they were fairly easy to modulate and had very little brake fade. After going to the Carbotech, he found he could brake much later without worry of over braking. And there is no brake fade at all now. Initial bite is stronger but easier to feel than the PFC's. Most tracks we run at, he has gone at least a second a lap faster since going to the carbotech pads. We also use Frozen Rotors. Makes a huge difference in longevity.

the problem i have is im running the ls430/rx7 brake swap, and as there are lots of pad choices for the rx7 caliper, the ls430, well not so much. im limited to oe replacements, ebc redstuff (whats in the car now) and carbotech. honestly i wish i had spent a little more time researching the ls430 swap before jumping in, by the time i realised the pad selection was so limited i already had the calipers rebuilt with fresh powder coat.

That is one thing I like about my brake swap. Early 996 GT3 / Turbo pads are basically the same cost as 951 pads, and the 330mm Cayenne rotors are much cheaper than 951 rotors. But honestly had I done a swap like yours, I never would have thought of brake pad availability, I've been so spoiled by Porsche options I'd never think that an ls430 would only have a couple options for better pads.

well, an ls430 only being 5 years of production, and being a run of the mill rwd sedan, its not likely too many people are looking for a performance oriented brake pad. the pads also only fit those calipers, there is no interchange. i do like the calipers, they are a beefy monoblock design, and radial mount making them easy to build a bracket. in reality there are a ton of different caliper options out there, at the time i was having almost no brakes with the single pot stock stuff and the ls430 seemed like a good way to go.

my rotor options are alright for my swap. im still running early n/a spindles (without speedo cable) and hubs, ive got a set of rotor adapters and run any 8x7" 2 piece rotor i want. currently running wilwood 12.19" x 1.25" rotors. they are also fairly cheap (at least for the cheaper ones) at $35 a rotor. the back is just 86 turbo rotors.

Carbotech will take any backing plate you want and apply one of their compounds to that backing plate. I run that on my LS430 setup with XP10s I think. It works great! Not that expensive either. All you need to do is supply them with a core backing plate from an old set of LS430 street pads. They will also add titanium plates for heat if you want. Hope this helps!

JP

sharkey wrote:the problem i have is im running the ls430/rx7 brake swap, and as there are lots of pad choices for the rx7 caliper, the ls430, well not so much. im limited to oe replacements, ebc redstuff (whats in the car now) and carbotech. honestly i wish i had spent a little more time researching the ls430 swap before jumping in, by the time i realised the pad selection was so limited i already had the calipers rebuilt with fresh powder coat.

they are making me a set, didnt ask for cores. i read something about them making their own backing plates now, although i dont know the truth of it.

sharkey wrote:they are making me a set, didnt ask for cores. i read something about them making their own backing plates now, although i dont know the truth of it.

They do make their own

pulled the front calipers off yesterday, and it appears i did have some issues going on. i did have a couple pistons just barley leaking, just enough to make the dust boost wet.

the bigger issue was how much force it took to get the pistons out of the bores. i always had issues with the pistons retracting too far, creating long pedal travel. the theory i read about that issue had to do with the square cut seals sticking to the pistons and just deflecting when the piston travels, and when you release the pedal the pistons retract. the info i found on this was exclusively on cars with manual brakes, and bikes. thinking about it, a power brake setup you would never really notice this happening in the pedal as you use a large bore master cylinder, the extra travel is negligable. i usually take calipers apart with compressed air, but 80psi wasnt enough to get the pistons to move, i ended up having to pry them out carefully with screw drivers, so piston stick was for sure an issue.

finding a solution came after a whole pile of research. ive always been taught, and always used brake fluid to assemble calipers and master cylinders. reading through some old porsche and triumph info i found online (both manual brake cars) they actually use a special grease inside the calipers to prevent seal sticking. i wasnt able to locate any of the products in north america for it, one was called red rubber grease, another was master cylinder lube. what i ended up with was something called Sil-glyde, a silicone grease used for caliper slides thats essentially just dielectric grease. i was real sceptical about a silicone product interacting with brake fluid, however i found lots of cases of people doing it with no issue, and i even found it listed on an old bottle of the stuff listing brake pistons as one of the recommended uses.

long story short, i now have the calipers rebuild using sil-glyde on the seals and pistons and im able to move the pistons in and out with one finger. thinking about it now, if i couldnt push the pistons out with 80 psi of air pressure, its like the master cylinder creating 80 psi less pressure. the brake calculator i use shows my front circuit should be 550 psi for -1.25g braking, 80+ psi less is a whole lot less stopping power.

one other small issue i noticed is something that should have dawned on me way back, and thats the pad hangs below the bottom of the rotor. in time this will create a lip on the pad, causing noises and possibly uneven wear. thats not too hard to fix, ill just chamfer the bottom edge of the pads.

I bet it stops a lot better now.

i dont know yet. calipers are all rebuilt, i just pulled the rotors off so they can get machined, and the pads should be here tomorrow. then it looks like rain for the next week, so it doesnt look like ill have much of a chance to get it back together.

sharkey wrote:they are making me a set, didnt ask for cores. i read something about them making their own backing plates now, although i dont know the truth of it.

Oh cool, even better! Let us know how they perform.

ill have an update on that once i get the car back together.

the pads did show up today, im happy with how they look (i mean, as much as i can be, they do just look like brake pads). one big thing i noticed is the front pads are smaller. i had the issue of the pad material coming off the bottom edge of the rotor about 5/16" on the back side with the old pads, the carbotech pads are nearly 0.200" shorter on the face, and a consistent height through the entire sweep. i still need to chamfer the pads a little, but its not nearly as big a deal as it seemed it would be.

had my dad take the rotors in to his shop and machine them today, i was quite surprised to hear how much runout they had. i guess between the rotor bolting to the adapter (cant really call it a rotor hat, its completely flat), then bolting the adapter to the back of the hub, it all adds up to around 0.018" on the worst front rotor. even one of the rear rotors had a fair bit of runout, and those are just one piece 86 turbo rotors with around 1000 km on them. im sure none of that was helping, although i never felt any brake pulsation.

of coarse it was a beautiful day today, and im held up by nobody in town having wheel seals in stock.

was doing a little idle tuning yesterday and i ran into my cooling system issue again. the car always ran a little hotter than i thought it should, and i chalked that up to poor radiator ducting. with that sorted out now i still appear to have the issue. i run a 180 degree thermostat, and the car is always running around 200*f, yesterday it was hovering between 201-203*f while idling in the driveway. i discovered when i turned my heater on low within about a minute the temp was down to 180 degrees and it would hover between 180-182*f.

the ecotec is no different than the LS regarding the cooling system, the coolant bypass is through the heater hoses and the engines are designed for use with a constant flowing heater core. when i put the car together iplumbed the turbo coolant lines in such a way that it should have acted as the bypass, and i used the original porsche coolant shutoff valve. the result appears to be that not enough coolant is flowing and the thermostat is sitting in water thats at least 20 degrees cooler than the rest of the engine.

so the end result now is to put a bypassing heater valve in. only problem is plumbing it next to a turbo manifold and downpipe and not melting anything.

cars all back together and on the road now. took if for a bit of a drive today and concentrated on seating the brakes. all i can say is holy crap does it stop now, like pulling me into the seat belt and momentarily turn the oil light on sort of stopping. i played around a little with the brake bias, i had it a little too far to the front and at 50km/h i locked up both front tires in a cloud of tire smoke, not exactly what i was trying to do but good to know the front brakes are sorted out. some more bias adjusting and it should be good.

the oil pressure is a little concerning. i didnt put much baffling in the oil pan when i built it, more than likely all i need is to add a little shelf on the front of the sump. im not really looking forward to pulling than pan off to fix it though. ive also been considering getting an accusump for the car as i do want to do some road racing in the future.

after a few days researching i settled on the fact i was gonna have to pull the pan and mod it with some baffles and trap doors as an accusump wasnt in the budget at the moment. looking back at some pics, the pan doesnt have a lot of room in it for a proper diamond baffle/trap door setup, id be able to do a front baffle and on one side of the pickup, leaving the pickup in the back right corner of the pan. combined with a top plate funneling oil into the back corner, i think it would work ok for the street but am still concerned about hard cornering. knowing what i know now, i would redesign the whole pan, have it a little deeper along with kick outs on either side, a centered pickup and a diamond baffle/trap door, and that may happen in the future.

well, i changed my mind on the weekend and this showed up today

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i was browsing amazon and ran across their listing for the accusump and they had one marked "used, very good condition", and the note said damaged package. for half $130 canadian (half of the new cost) and free shipping i took a chance, it showed up today in its slightly damaged box with the unit in perfect shape. score. the rest of the cost comes with the solenoid kit, and then various -10AN fittings to plumb it in. still not in the budget right now, but id much rather not thrash the bearings out of the motor.

and the cooling system saga continues

like ive said before, the car always seemed to run hotter than i thought it should, but never alarmingly hot. its started in the past few days runnin a little hotter on the highway, climbing up over 212, but once i get the rpm up, even for a short amount of time, the temps fall right down to 180 and will sit there for a short amount of time, and then slowly climb back up again. it was acting like a slipping water pump impeller, and mine is a plastic one, but i pulled it apart to have a look and the pump is fine.

i had my old man lave a look at everything, and his thoughts were the thermostat isnt opening at the correct temps, and it goes beyond the thermostat itself, its more to do with my location. i cut up the and removed the thermostat from the back corner of the block and only left the heater core outlet back there and put a thermostat on the back of the water pump, eliminating the water pump tube, and the heater return dumps right back on the thermostat. flow wise, its exactly the same as a factory engine, just with components moved around. what we came up with is because the thermostat is away from the hot coolant thats exiting the block its causing the thermostat to be in a cool area, and when it does open its closing right away because of the rush of cold coolant from the rad. also, at higher rpm the increased flow through the heater hoses dumps a bunch of hot coolant right on the thermostat so its able to stay open longer and allows the engine to cool properly. he also thought the bypassing heater valve i just installed may be restrictive, and that doesnt help things.

we decided as a test to put it back together and just bypass the heater and valve completely and see what happens. if it gets even a little better itll prove the theory, and that might mean having to attempt to go back to a stock thermostat housing. that may mean redesigning much of the hot side of the turbo setup.

i stuck the car back together on friday so i could drive the car on the weekend (we had our big local indoor car show on the weekend, my shop had a booth and while my car wasnt going in the show i still wanted to drive it there), i bypassed the heater core and while it did change things a little, its not fixed. i dug out my infrared temp gun and confirmed the problem, when the coolant around the temp sensors is showing 205*f the thermostat housing is barely at 180*f. after holding the rpm up for 10 seconds the thermostat housing heated up to 190*f and the temps started coming down, then the thermostat housing cooled back off and the temps started climbing again.

the fix, well im not 100% sure. the next thing im going to try is removing the thermostat from the inlet to the water pump and run a remote thermostat housing off the outlet on the head. ill be removing the heater hose from the back of the block and running it off the thermostat housing on the engine side, this should allow coolant to circulate through the block and head while the thermostat is closed. i figure this is worth a shot, i had a better look at what it would take to get the stock thermostat housing to work, its far from simple. it would take a new turbo manifold that moves the turbo forward almost a foot, id then be able to drop the downpipe quite far forward, leaving me enough room to use the thermostat housing and run a lower run hose to it. that or just stick a "hater pipe" out the hood.

since im waiting for parts to sort out the cooling system i thought id start on the accusump oil accumulator.

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im mounting it in the dead space behind the nose panel. plumbing it in is real simple as the oil cooler is right behind it. i added a T on the outlet from the oil cooler, this is where the accumulator will plumb into, and on the inlet side of the cooler i added a check valve to ensure when the oil pressure drops and the accumulator is feeding oil that the oil goes to the bearings and not back to the oil pan. im waiting for some fittings to come in, im hoping to button up the mechanicals of the install tomorrow, just leaving the wiring.

Maybe you could try drilling a hole in the thermostat. It’s a cheap experiment. It will allow some coolant to always circulate so the thermostat will be exposed to coolant that is the same temperature as what the sensor is reading. Maybe...

actually that would make things worse. the thermostat is on the cold side of the rad, so having a small amount of coolant flowing all the time is going to keep the thermostat cooler.

the accusump is all plumbed in. i have yet to run the car with it installed, part of the install required me to install a new oil pressure sender. (the porsche sender is a huge m18 thread, i put it in my remote oil filter mount, however the filter is plumbed before the accusump so it wouldn't still show a pressure loss when the accusump kicks on. i found a sender compatible with the stock gauges that's 1/8npt, along with the autometer adapter it's now in the block) to get to the oil pressure port on the block for the sending unit required me to pull the intake manifold off, so i ended up draining the coolant to get the coolant tank out of my way, and then i just started doing the cooling system mods.

ive got the cooling system close to finished, i just have to button up a few things. ive run with the idea of putting the thermostat up at the outlet of the head, and ive now plumbed my heater feed and turbo coolant feed off the new thermostat housing. the return for both is at the water inlet to the pump, this will allow coolant to circulate through the engine and get hot coolant around the thermostat. here is a diagram i found online

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Take a look at this Sharkey. I ran one of these on a 944 race car and it worked great.

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It goes in-line in your radiator hose. It has a nipple to allow you to run a hose from the hot side of your cooling system to make the t-stat work properly.

thats essentially what i did. im running a meziere remote thermostat housing and added in fittings for the heater hose and the turbo coolant fed. ill grab some pics later on.

i had it running last night, i wont know 100% but it seems to be working so far. it hits 170 degrees, thermostat pops open and the temp stays within a couple degrees. i may now have to move my coolant temp sensor that feeds the ecm, its now in colder coolant and seems to read low compared to actual engine temp.

the end result seems to be a success in the cooling department. i finished it up last night and took it for a drive today. it takes quite a while for it to get up to temp, but once it does it sits at 185 while driving, and the temps will climb up while sitting till the fan comes on and cools it down. i may need to move my coolant temp sensor, i moved it from the water pump inlet (thats now a cool spot without the thermostat in front of it) to the factory location on the back corner of the block, however to clear the turbo manifold i had to put it in an elbow, so thats likely causing a slow response on the gauge. ideally it should be in the top of the head. the supercharged ecotecs had the sensor here, i have a steam port in that location on this engine, im trying to figure out what thread size that sensor is.

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the accusump, im not sure if its solved my problem yet. when i prelube the engine my oil pressure gauge doesnt climb, and when i got hard on the brakes it still drops oil pressure. i know the unit is working, it holds pressure and then drops it when i prime the engine. i need to look at the oil system diagram, im thinking the pressure port for the sending unit is between the pump and the filter housing. if thats the case it would explain it. only other thing i can think of is the check valve is not working.

a whole month without an update, kinda nice to not be working on the car all the time lol. havent done much with it, just driving it a little bit. everything has been pretty happy and working alright.

i did decide a few weeks ago that i should have a look at the plugs, and i discovered everything was full of water again (stupid hood scoop) from sitting all last year in the weather, and as a result the coils and springs were all rusted, so i stuck a set of zzp lsj coils into it.

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ive finally collected up the remaining pieces to build the swaybar setup for both the front and rear.

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the front links were one of the things holding me up. the link bolts straight down into the control arm, so i decided i wanted whats essentially an inline ball rod end. i found some universal pieces that seems like the right thing, but once i got them they were just too wimpy. what i ended up getting was some swaybar links for a 2003+ dodge ram. i cut the links down, turned them down on the lathe, and threaded them so i can use them as a rod end. on the other end ill use a normal heim joint.  here is a before and after

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to complete the links i wanted some hex stock to make them easy to adjust. now it seems hex stock in my area is impossible to find, so i got creative and started with this

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more on that later.


and one more addition, still need to make the bracket, but i figure this is a must

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