When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
We may be selling our OSG diff. Currently in an RX8 pumpkin ready to drop in, and will include some extra OSG diff fluid (enough for at least the first fill up). Thinking $1500 for the full assembly plus fluid is fair?
We pulled the engine mount for ours too. Maybe we could have snaked it in, but it was going to be a PITA. Also word of advice, torque the hardest to get nuts first while the other pieces are still floating and easy to move out of the way.
I was able to get the front pipe installed with the engine mount on, but then couldn't get the other pipes in because the mount was in the way taking up too much maneuvering room.
We may be selling our OSG diff. Currently in an RX8 pumpkin ready to drop in, and will include some extra OSG diff fluid (enough for at least the first fill up). Thinking $1500 for the full assembly plus fluid is fair?
I think everyone will be more interested in why it's coming out and what you intend to replace it with?
I have a 5.10 final drive for sale if anyone is interested.
Team you should sell that header start a group buy. renesis needs more parts for sale only one long tube header on the market that cost an arm, a leg and a few fingers off your good hand.
We can only use the 4.44 or 4.77 as supplied by Mazda, not the 5.12. It'd be too low for us unless paired with a close ratio trans, which we can only use the unmodifed S1 or S2 trans too.
Holy crap this thread blew up since the last time I checked it.
I'm finally in a position to come play a bit and I'm excited. Real job + blowing up the other project means it's time to focus on the RX8 that's been sitting in the driveway for a year+. Just got the cooling system hopefully sorted back out, only thing left will be a reservoir(I don't trust this stock one very much anymore), going to be pulling speakers/amps/etc this weekend. Stealing an idea I saw on here and building a battery box next week for the PC680 that drops it down between the engine and cross member. Will also cut aluminum for a splitter when I get that part waterjet'd.
I skimmed through the last 20 or so pages(my questions are probably answered in there but it didn't jump out at me), but has anyone managed to find a solution to an intake to run? I have an AEM laying in the garage but iirc we can't run them because you have to remove the plastic piece behind the bumper support. I'm just trying to clean up the engine bay and not lose power, not really looking for any gains.
Second question is suspension... While I would love to go MCS I can't afford that right now, plus the end goal is going to be a TT3 car so it would be a bit of overkill for 99% of that. Looking at the FCM setup it seems to be a good middle ground that would be easy to convert to road course whenever the engine lets go and FI happens for TT3. Thoughts?
I'm seriously excited to get back into autocrossing, let's show those 330's who's boss.
Last edited by roflcopter; 11-03-2017 at 11:13 AM.
Reason: FCM not FSM...
That was likely my idea from way back when. I do not recommend having the battery anywhere near the radiator and certainly not in the discharge air flow path, but preferably not even in the engine bay. I don’t recommend a PC680 either. IMO the A-Hr capacity is too low and it also has a max temperature rating of 177*F if you use the metal-jacketed version. The standard one is only rated for 140*F or something. I never got more than 6 - 12 months out of the jacketed PC680 version in that location.
That was likely my idea from way back when. I do not recommend having the battery anywhere near the radiator and certainly not in the discharge air flow path, but preferably not even in the engine bay. I don’t recommend a PC680 either. IMO the A-Hr capacity is too low and it also has a max temperature rating of 177*F if you use the metal-jacketed version. The standard one is only rated for 140*F or something. I never got more than 6 - 12 months out of the jacketed PC680 version in that location.
Darn. I liked the idea and REALLY liked not having to extend the stock battery cables. I would really prefer not to relocate to the trunk just because I don't want to run wires that far and through the cabin. I've heard mixed reviews about the PC680 but for the price...
This isn't going to live in the car either, and this car isn't going to see much run time other than events so maybe I'll get better mileage?
You can just modify the AEM and have a filter horizontal over the tray (see my pic a page or two back, though I’m also adding a second side filter), or you could just do the RB intake box and live with the radiator blasting it
Well you know the engine needs good cranking power so it’s your call, but at least use the metal jacket version and try to insulate or maybe route cool air from the nose if you can.
PC680MJ is about 16 lbs and only has 16 Ah capacity, while a PC925MJ is about 24 lbs with 28Ah capacity for about $70 more, has a larger profile though
I already have the PC680MJT in a bracket I pieced together in the car, so I'll at least run it until if gives me issues. Living on a battery tender 99% of the time will hopefully help it.
If I go through with making the nicer bracket I will look into providing a shield of sorts to air-gap it from the direct flow off the radiator, should knock a decent bit off the temps.
Another question for those of you in the know... I had been running the 285/30/18 BFGs previously and ran into a ton of rubbing issues(switching to Hoosiers should fix some of that since they aren't quite as beefy) but I know on the BFGs I was hurting for a little more front camber, are any of you running the whiteline offset bushings for the upper control arm to gain that extra little bit, or do the Hoosiers do better and not need it?
We are running the 3lb LiFePO4 Battery Tender battery and have had good luck with it. The car lives on a tender between events though. It even starts the car in 40 degree weather running ethanol, which is pretty impressive.
We also still have our battery in the front. We did pour foam and fully insulated it inside of the OEM battery box, with a new stand holding it in place. We've put over 350 runs on the car this season and so far it's still holding up fine... knock on wood. We pull it out pretty frequently and check it.
On your other questions, the single best thing you can spend money on is good shocks. Buy the best ones you can afford, and skip the aero and intake and other things if you need to save money, you won't regret it. Our Penskes are the #1 best thing we put on the car. We went with Anze - the magic is in the valving.
On wheels and tires, 275/35/17 on 949 6UL's (with 3-5mm spacers) fit with barely even rolling and you can go lock to lock. We also run 295's, but those are much harder to fit (significant pulling/rolling some plastic cutting, steering limiters, etc.). I'm not sure which is faster, since the 295's are quite a bit taller and hurt the gearing. Easy button are a set of 275s with high offset wheels...
Run as much camber as you can get without sacrificing your braking ability too much. You will most likely need offset UCA bushings. Our current set of 275 A7's are at 190 runs and still haven't corded... camber is good for extending tire life We are going to another event tomorrow so we will see if they make it #missioncordthehoosiers
We are running the OEM intake so can't help you there.
cut your fenders and use steering limiters because camber won’t cure rubbing
Pretty sure the Hoosiers need the same or more camber; see the alignment thread here in the race forum.
The fenders are already rolled/pulled and I fit the 285's decently, only issue is on the pinch weld(have to play with caster to get it to clear), my rubbing issue and the camber question were not meant to be related, I phrased it pretty poorly though!
Originally Posted by Tamra
On your other questions, the single best thing you can spend money on is good shocks. Buy the best ones you can afford, and skip the aero and intake and other things if you need to save money, you won't regret it. Our Penskes are the #1 best thing we put on the car. We went with Anze - the magic is in the valving.
On wheels and tires, 275/35/17 on 949 6UL's (with 3-5mm spacers) fit with barely even rolling and you can go lock to lock. We also run 295's, but those are much harder to fit (significant pulling/rolling some plastic cutting, steering limiters, etc.). I'm not sure which is faster, since the 295's are quite a bit taller and hurt the gearing. Easy button are a set of 275s with high offset wheels...
Run as much camber as you can get without sacrificing your braking ability too much. You will most likely need offset UCA bushings.
My current setup(what I was running the last time I autocrossed it over a year ago) is 18x10 +38 RPF1s with the 285/30R18 BFG R1S's, with as much camber as we could put into the front(around 2.6 degrees iirc) on the stock setup the tires still wanted a tad more(based on temperature readings across the tire and blowing the shoulders off of them in 4 events).
As far as suspension goes I definitely agree that shocks are the biggest thing you can do to get the tires working properly. I'm not in the realm of affording Penske's, MCS, etc yet, so I had been looking at the Fat Cat Motorsports options... they are just Bilsteins PSS9s(or 10s if you're so inclined) but he works magic on the valving as well as working with you on the math to get the right springs(and shocks valved for them) as well as bumpstops, etc to get the car sorted. Is anyone we know running one of his setups? I know he's had a decent bit of success in the Miata world and offers all the products for the RX8 as well since the NC and us are so close suspension wise.
Well a 285/30-18 Goodyear is only 0.1” radius more than a 275/35-17 Hoosier, but it’s potentially about 1/2” wider depending on wheel width. The 295/35-17 Hoosier is only 0.3” larger radius than the 275, but again is potentially wider. That’s not “quite a bit taller” in my book (only 2.4% difference between 275 and 295). You could easily raise your ride height 1/4” -1/2” without any major consequence. I’d suggest the larger width is what’s mostly causing the fitment difference with the exception of the pinch weld in the rear of the front wheel well. Then that becomes a steering limiter function. WRT performance difference, you might not see much or any gain if you use the same wheel width for the wider tire as the narrower tire.
Running wider wheels and tires is generally going to have a triple whammy of increased total/sprung/rotational weight though. Regarding tire diameter, the general impacts are small on overall gear ratio. Going from the 275 to the 285 is about a 1% decrease (4.40/4.73) and for the 295 only a 2.4% decrease (4.33/4.66) in effective rear gear ratio while the difference and even a 315 is only a 3.5% decrease (4.28/4.60) in rear gear ratio. If you’re on the 4.44 rear gear then those might be a step back, but on the 4.77 gear it’d probably be better. While the shorter S2 gear gives up some top speed potential, you gain some of it back with a taller tire and then you’re also still gaining some gearing advantage to offset two of the three weight impacts.
What it all means in total is harder to discern, but it’s often the total package that matters more than just any one thing. The thing is, if you want to run the really wider tire wheel package you can’t be shy about cutting out anything within the allowed limits. If you need to be economical then sticking with the narrower setup makes the most sense.
Yeah, the gearing/weight differences seem to be mostly inconsequential with this car as far as what I've felt and seen. My clearance issues are non-existent except for the pinch weld, I rub just a hair on the rears at full compression(should fix that when I go to the stiffer springs and all) but the width of the tire up front is the major issue with that pinch weld.
I was having a discussion with a few autoxers two weeks ago(one of them a national champion) and we were discussing the idea of throwing some big, meaty tires on there(think 315 or larger) as a sacrificial and basically cranking it lock to lock around a parking lot at slow speeds to "self clearance" the pinch weld out of the way... As we all know it is inboard of the hub-face and thus we can't take a hammer to it, but there are provisions in the rules for "wear and tear"...
If the pinch weld gets messed up one way or another, it wouldn't be legal. You would need to find a legal way to fit them (if you even can), sorry. Enough people know the RX8 can't fit 315's due to the pinch weld issue that if you started winning it would definitely be questioned LOL. I heard of someone who had a car that had self clearanced to fit wider tires and they were protested at a national event.
Also, we can feel the gearing and/or rotating weight difference going from the 275 to the 295. The car accelerates way doggier with the 295s, although the sweeper grip is higher. Not sure ultimately which is faster, but I think it might be close. We haven't done a back to back test to know.
09-27-2017, 07:04 AM
We are going to another event tomorrow so we will see if they make it #missioncordthehoosiers