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First track day was a huge success.
Day 1 session1 I beat my best in my rx7 on Avon slicks by 3 seconds. I spent the remainder of a very hot day figuring out different ways of getting the car around the track. The extra speed and ability to use the rumbles and curbing changed my braking and turn in points.
Day 2 session 1 I picked up another 2 seconds and is the video below. It wasn't a perfect run by any means. I brake way to early at turn 1, to much braking in a few places and blew turn 13 completely.
If you listen you'll hear my rpms fluctuate down the straight. I think I had to much rear rebound dampening. The rear felt a little unsettled during some braking situations also but was great once the the car settled into a turn. Corner Exit balance was good.
some notes for other lfx swap guys.
the Camaro stock diff is clutch type, however it doesn't lock very well. I put redline 75w/140ns in for the track day with very little friction modifier. I had no detectable chatter and a few times spun the inside tire. Booooo.
To be fair its possible I was lifting or really unloading that tire with my rebound being set to high.
I run rotella t6 15w40. I hade very little in my catch can after 6 sessions on track. I assume this is because the oil did a good job of not turning to mist/vaporizing. Anyways I wasn't sucking it though my intake which is good. This is a great oil for rotary engines also. If you have a cat, maybe not the best choice.
90's with Louisiana high humidity.
Oil temps got up to 260 using the drivers side oil cooler.
the domestic guys all thought this was fine saying we see up to 300. Nope! Going to put the setrab from my rx7 on the rx8. 210-225 is the green zone. I shut my rx7 down if it went above 230.
800/550 spring rates felt great. Steady state grip was very balanced.
Federal fz201 medium compound 100tw tires were very good. I did learn rather quickly that they do take some time to heat up. For a track day it's great. You can run your warmup as usual then I'd say 80% on the first green lap.
It worked out well for me. It forced me to work up to my pace and made it easier to execute my plan for the session.
Maximum grip was great. I never managed to go fast enough to get them making much noise or start sliding around. They also never got greasy.
for reference I ran a 2:03
Track record territory at Nola for tt3 on fresh Hoosiers 1:51A fast spec miata qualifying lap is around 1:58
I have a dsc abs module that's controlled by the stock ecu.
I actually forgot about this till a friend asked about it.
I didn't notice that the DSC was doing anything on track. My friend mentioned when it fails it's quite exciting.
Would you recommend switching to the non dsc module for a track car?
I also need to limit my steering. With my camber adjustments my wheel hits the spring.
you just have to turn it off via the DSC button-switch on the center console, except with your swap I’m not sure if it’s still functioning or not.
The brake lines are different on the non-DSC module. So you’ll need those too. Maybe the MC too, but I can’t remember exactly. Been discussed on here somewhere if you want to snoop around.
if it’s a used module then it has to have the ID initialized into the CAN system with Mazda or aftermarket software. A new one doesn’t require that, but costs mega $$$.
some notes for other lfx swap guys.
the Camaro stock diff is clutch type, however it doesn't lock very well. I put redline 75w/140ns in for the track day with very little friction modifier. I had no detectable chatter and a few times spun the inside tire. Booooo.
To be fair its possible I was lifting or really unloading that tire with my rebound being set to high.
I run rotella t6 15w40. I hade very little in my catch can after 6 sessions on track. I assume this is because the oil did a good job of not turning to mist/vaporizing. Anyways I wasn't sucking it though my intake which is good. This is a great oil for rotary engines also. If you have a cat, maybe not the best choice.
90's with Louisiana high humidity.
Oil temps got up to 260 using the drivers side oil cooler.
the domestic guys all thought this was fine saying we see up to 300. Nope! Going to put the setrab from my rx7 on the rx8. 210-225 is the green zone. I shut my rx7 down if it went above 230.
800/550 spring rates felt great. Steady state grip was very balanced.
Federal fz201 medium compound 100tw tires were very good. I did learn rather quickly that they do take some time to heat up. For a track day it's great. You can run your warmup as usual then I'd say 80% on the first green lap.
It worked out well for me. It forced me to work up to my pace and made it easier to execute my plan for the session.
Maximum grip was great. I never managed to go fast enough to get them making much noise or start sliding around. They also never got greasy.
for reference I ran a 2:03
Track record territory at Nola for tt3 on fresh Hoosiers 1:51A fast spec miata qualifying lap is around 1:58
Glad you're enjoying it. Is it possible you don't have enough droop travel in the back? It seems like a common problem with off-the-shelf RX-8 rear damper packages.
Glad you're enjoying it. Is it possible you don't have enough droop travel in the back? It seems like a common problem with off-the-shelf RX-8 rear damper packages.
I measured droop travel today. A little over 3 inches at 14" rear ride height measured from wheel center to fender.
When the drivers side rear is compressed and the right rear is in droop it takes about 2.5" of droop to get that tire light enough to spin. I used a steep driveway and an angled approach to get this to happen. This does not happen on the stock suspension.
Quick recap. Rpm flutter down bumpy straight. Spin inside tire on some corner exits. Usually poor exits.
was thinking rebound set to high. Basically jacking down.
Rebound could be part of the problem, but as John noted droop can be an issue. I think he's right.
here's what I'm thinking.
when the rear spring unloads it's no longer forcing the wheel down. Rebound setting isn't going to matter much at this point. I have 7.5 total travel. My ride height setting gives me about 3" of droop max.
I'm thinking the answer here is to run a tender spring instead of a helper. The tender would have be 50-100lbs and have a compressed height of 1" ish. It would effectively be there to extend the shock and be compressed the rest of the time.
A 6" main spring would give me the travel required. It would bind right about when the shock would bottom out.
Nice tread and so glad this swap is still getting exposure! I ran with Hoosiers 🙂. I also discovered the chassis liked a little rake in it ( rear higher). Of course you do have a little higher torque than I ever did... but don’t think by much? Would backing off the rear camber help? Tire pressures good?
Nice tread and so glad this swap is still getting exposure! I ran with Hoosiers 🙂. I also discovered the chassis liked a little rake in it ( rear higher). Of course you do have a little higher torque than I ever did... but don’t think by much? Would backing off the rear camber help? Tire pressures good?
Haven't hit the dyno yet but I'd guess between 240 to 275 torque based on what Camaro guys are getting. I have a few changes lined up and need to get a baseline before I do anything so should have that soon.
I have a rather mild alignment, but seems to be wearing even so far.
camber 2.5f 2.0r
i targeted 30psi hot
The car was surprisingly neutral. Except under hard braking and even that was manageable. I never had any oh **** moments, mostly just oh, it gets loose under hard braking I guess I have to be gentle with steering inputs. III didnt even notice it anymore by the end of the day. Of course I probably wasn't going fast enough =)
I'm a little on the tall side of ride height I think, 13.5 front 14 rear. I plan on dropping it an inch all around and see how that feels.
I still have stock rear links and it was suggested those may be limiting my droop also. Makes sense on some cars, so I'll take a look and replace what needs replacing.
Quick recap. Rpm flutter down bumpy straight. Spin inside tire on some corner exits. Usually poor exits.
was thinking rebound set to high. Basically jacking down.
Rebound could be part of the problem, but as John noted droop can be an issue. I think he's right.
here's what I'm thinking.
when the rear spring unloads it's no longer forcing the wheel down. Rebound setting isn't going to matter much at this point. I have 7.5 total travel. My ride height setting gives me about 3" of droop max.
I'm thinking the answer here is to run a tender spring instead of a helper. The tender would have be 50-100lbs and have a compressed height of 1" ish. It would effectively be there to extend the shock and be compressed the rest of the time.
A 6" main spring would give me the travel required. It would bind right about when the shock would bottom out.
Is this a dumb idea?
I'm probably not the right person to ask, but I like the idea of a positive-rate tender versus a zero-rate helper. The helpers don't really do anything beyond keeping the spring from coming unseated. The tender theoretically should add some spring force to extend the shock to full droop. My current setup uses a strong tender spring stacked with a 6" main spring in the rear. My car had a lot of issues last year but inside-rear wheelspin wasn't one of them, and I run an Eaton Tru-Trac, which is a torque biasing differential.
I do remember some squirrelly high speed ( approx 135 to 60 mph ) braking when I was just running aftermarket springs and shocks. That disappeared when I put on the kw3 system With about 1 inch of rake. What sways are you running? You do have approx 50 ft lbs more torque...I was around 220 or so.
Perhaps also that the center of gravity has changed due to the drivetrain swap and the yaw and pitch characteristics Etc are a little different? If so then my cars experience wouldn’t relate?
What is apparate however is that you are having a lot of fun! Sweet car dude...following all of this.
1” of rake to me suggests a spring/bar imbalance issue, but that could depend on aero components (splitter, wing, etc.) relative to spring rate and the true dynamic rake at speed. I usually think of rake in the 1/4”-1/2” range, usually on the lesser side if any at all.
I don’t recall what swaybars you have(?), but the only time I ever experienced inside wheel spin on an RX8 is when something broke on the front swaybar. That was the OE diff though.
You have the Camaro diff setup right? The swaybar issue aside, I’d replace that first. It’s not really setup from GM for track cornering. OS Giken would be my preference; not the cheapest option, but is really what you need for track use.
1” of rake to me suggests a spring/bar imbalance issue, but that could depend on aero components (splitter, wing, etc.) relative to spring rate and the true dynamic rake at speed. I usually think of rake in the 1/4”-1/2” range, usually on the lesser side if any at all.
I don’t recall what swaybars you have(?), but the only time I ever experienced inside wheel spin on an RX8 is when something broke on the front swaybar. That was the OE diff though.
You have the Camaro diff setup right? The swaybar issue aside, I’d replace that first. It’s not really setup from GM for track cornering. OS Giken would be my preference; not the cheapest option, but is really what you need for track use.
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I have a 30.5mm solid bar up front and whatever a stock auto has in the rear. Steady state cornering felt good.
I replaced my 8" springs with 7" in the rear, the car is level now. I was happy to see I could swap springs without removing the whole damper. I see 6" rear springs with a tender In my future, but I'll try this first.
I do have the Camaro diff, it's marginal at best. Lotta slippage differential would be an apt name.
The OS Giken's will probably end up being an early Xmas present to myself.
Going to start replacing rear links also.
I’d agree that rear rebound is possibly too high at a minimum, which is not only going to be jacking the car down on rapid bumps down the straight and making it squirrelly under braking, but is also going to work against the inside rear tire staying in contact for bumps and curbs when cornering. With a helper it could even exacerbate because the correct rebound for the main spring is going to overwhelm a helper. It’d just depend on body roll vs. spring travel position/range. It get’s a bit complicated, but with a helper be sure to think it through carefully because the helper eats up shaft travel (helper coil bind height) and you have to consider that against coil bind height of the shorter main spring relative to overall travel.
However, thinking I’d want to have a much stiffer front bar and more rear spring rate based on what you stated so far.
Team is the man here... lots of real world experience. Squirrely rear end used to cause me to activate my emergency pucker death hold on the seat
looking at your vids.. It seems the track has a lot of small dips? That does make it very tricky.
Last edited by olddragger; 07-12-2020 at 08:49 PM.
I appreciate when he chimes in. I'm going to hold off on the helper spring idea for now. The damper and ride height changes are a good place to start.
I live in Florida, so I'm rather reluctant to attend an autox event right now but I think that would be the best/safe place to do some testing and see if sway bar changes are needed.
I feel pretty good about the spring rates. Steady state sweepers felt good, I may have had slight on throttle understeer but I'm ok with that right now.
my home track, NOLA is a in a swamp so it's constantly moving and changing. It's not really jarringly bumpy for most people, just wavy spots here and there.
the guys in BMW's sail over them smooth as silk.
yeah, but the issues indicate an overall setup problem. Hence my prior suggestion. You can have steady state cornering balance on a crap setup. It won’t be as fast as the optimum setup, either in either steady state - transitional cornering or non-corning too.
The plan this weekend was to mount this rather large setrab in the nose of the rx8
After dealing with multiple seized up fender liner fasteners and got the nose off I realized just how little space I have.
I have no idea how a typical rx8 radiator is mounted buy mine lays down quite a bit. It's also not a terribly large radiator. I'm impressed that it keeps the car cool. I attribute this to the pretty fantastic factory ducting.
Was just scouting things out this evening to see what I would need to do. Looks like I can make a simple bracket that attaches to the underside of the bumper for the top.
There are 2 bungs on the end tank of the radiator. I'm going to use those for the lower mount. There really isn't anything else up there to work with unfortunately. Looking at this pic I guess I need to check if I can sneak around the side of the radiator for the lower cooler mount.
Look at this tiny filter. It's the size of a coke can =)
I'm not sure how this area is getting cool air but it does. My intake air temps are pretty decent. This areas a project for another weekend.
260f is getting a little warm but from what I understand this engine can take 275f per the engineers? What are your coolant temps? Perhaps running a better oil would lower the temps a little also? When I switched from a Pennzoil 5w/40 to Redline 10/40 my oil temp dropped almost 10 degrees.Same track but different days...so hard to call it apple to apple comparison. Still it helped temps. My water coolant temps never got over 210f.
If you can drop your coolant temp some the oil temps will also drop.
06-23-2020, 11:41 AM
