97 Rotrex HPDE Build
I see that you're using pretty thick aluminum, but you'll probably want to check occasionally that its not allow the oil cooler and radiator to rub together. Either that or put some thick foam or bulb seal between the two as a barrier.
Yeah, I'll definitely check after the first drive or two. I can shim the mounts out with washers if they are too close together.
Looking good. The NA apparently has less room than the NB between the swaybar and the front of the engine. I have more clearance between my RB bar and the damper. I've only got about 1/2", maybe 3/4", between the swaybar and the oil cooler though.
Car started and runs, now I need to do some tuning... My plan is to just set autotune on easy change and drive around. Do I need to do anything else?I've only changed the head and IM, so should be getting more flow/less boost in regards to my last setup.
Could someone double check my fuel/timing maps? I am running a Rotrex at around 8-9 psi and am at altitude (5000-6000ft) and on 91 gas. These maps worked well on my previous setup for 4-5 track days, so I know I'm not getting any detonation (as I've pulled the head and inspected since then).
Fuel:

Timing:

Thoughts?
Could someone double check my fuel/timing maps? I am running a Rotrex at around 8-9 psi and am at altitude (5000-6000ft) and on 91 gas. These maps worked well on my previous setup for 4-5 track days, so I know I'm not getting any detonation (as I've pulled the head and inspected since then).
Fuel:

Timing:

Thoughts?
Timing table looks conservative.
On the AFR table, I would go richer more quickly. I'd like to see 13ish in the 85kPa region, 12.5 by 100kPa going richer after that (like you've done) for det protection. Especially in the lower RPM regions where you're lugging the engine (you probably didn't hit those regions much during your track days). Best power comes at 12.5 to 13.
I would also check your static/engine-off MAP reading. MS1s especially could be off substantially. I've got one that reads 88kPa (true reading would be 98-99kPa). If you have this condition, then you need to adjust the tables to compensate. I don't think this is much of an issue with MS2 or 3.
On the AFR table, I would go richer more quickly. I'd like to see 13ish in the 85kPa region, 12.5 by 100kPa going richer after that (like you've done) for det protection. Especially in the lower RPM regions where you're lugging the engine (you probably didn't hit those regions much during your track days). Best power comes at 12.5 to 13.
I would also check your static/engine-off MAP reading. MS1s especially could be off substantially. I've got one that reads 88kPa (true reading would be 98-99kPa). If you have this condition, then you need to adjust the tables to compensate. I don't think this is much of an issue with MS2 or 3.
Ditto the AFR's. I would bring the 100kpa row closer to 12.2, 85kpa closer to 12.8. I see the AFR slope that matches a Rotrex boost curve but even 1psi on a hot day will ping if its run too close to N/A AFR's.
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Timing table looks conservative.
On the AFR table, I would go richer more quickly. I'd like to see 13ish in the 85kPa region, 12.5 by 100kPa going richer after that (like you've done) for det protection. Especially in the lower RPM regions where you're lugging the engine (you probably didn't hit those regions much during your track days). Best power comes at 12.5 to 13.
I would also check your static/engine-off MAP reading. MS1s especially could be off substantially. I've got one that reads 88kPa (true reading would be 98-99kPa). If you have this condition, then you need to adjust the tables to compensate. I don't think this is much of an issue with MS2 or 3.
On the AFR table, I would go richer more quickly. I'd like to see 13ish in the 85kPa region, 12.5 by 100kPa going richer after that (like you've done) for det protection. Especially in the lower RPM regions where you're lugging the engine (you probably didn't hit those regions much during your track days). Best power comes at 12.5 to 13.
I would also check your static/engine-off MAP reading. MS1s especially could be off substantially. I've got one that reads 88kPa (true reading would be 98-99kPa). If you have this condition, then you need to adjust the tables to compensate. I don't think this is much of an issue with MS2 or 3.
Thanks for the input guys. I'll change the AFR table before I start autotuning. I also want to make a set of detcans before I start messing with the timing table. Conservative=good in my book, I don't need to be on the ragged edge.
Rick- I just saw your thread- nice work at the TT! I'm thinking I might want to try some of those next year...

This is an awesome build thread, I really dig the car. A rotrex set up is what I'd like to eventually do with my TTD car and move up to TTC or B.
A quick note, and I hate to be that guy, but I think it's worth pointing out. Your downshifts are really upsetting the car. It's kind of weird, you're heel-toe blipping the throttle on braking, but you let the revs drop again before actually letting the clutch back out, and let the wheels rev the engine back up. This is causing a lot of tire chirping, and a few times is what kicks your car sideways. See post #53 video around 2:16. The slide seems to be entirely caused by the clutch dump. Working on accurate downshifts will keep the car much more settled going into turns, and should drop your lap times dramatically.
A quick note, and I hate to be that guy, but I think it's worth pointing out. Your downshifts are really upsetting the car. It's kind of weird, you're heel-toe blipping the throttle on braking, but you let the revs drop again before actually letting the clutch back out, and let the wheels rev the engine back up. This is causing a lot of tire chirping, and a few times is what kicks your car sideways. See post #53 video around 2:16. The slide seems to be entirely caused by the clutch dump. Working on accurate downshifts will keep the car much more settled going into turns, and should drop your lap times dramatically.
This is an awesome build thread, I really dig the car. A rotrex set up is what I'd like to eventually do with my TTD car and move up to TTC or B.
A quick note, and I hate to be that guy, but I think it's worth pointing out. Your downshifts are really upsetting the car. It's kind of weird, you're heel-toe blipping the throttle on braking, but you let the revs drop again before actually letting the clutch back out, and let the wheels rev the engine back up.
A quick note, and I hate to be that guy, but I think it's worth pointing out. Your downshifts are really upsetting the car. It's kind of weird, you're heel-toe blipping the throttle on braking, but you let the revs drop again before actually letting the clutch back out, and let the wheels rev the engine back up.
Yeah- I know I do that, I need to be a little quicker letting off the clutch... Trying to work on it, but bad habits are hard to fix! Good luck with your brake install.

Drove the car for about an hour, bearing seized on one of the tensioner pulleys and melted my belt, a camshaft seal leaks and my 3rd gear synchro feels like it's dying. Car ran great otherwise.
I changed the trans fluid to amsoil (whatever all the track threads recommended) and it feels better shifting to all the gears, except 3rd feels way worse than before. Not sure what's going on, but I'm gonna try that ford magic stuff. It feels like i'd grenade 3rd if I go to the track like this.
Also found replacement bearings for the pulley from mc-master carr, they are rated to 13000 rpm. At redline this pulley is probably doing about 18000 according to my calcs. Probably why it blew up in the first place- thanks Kraftwerks!
Sweet jesus! That was the fixed idler, right? bocabearings.com should have higher speed rated bearings unless you want to go down the path of ceramic bearing madness the Honda guys are using.
It took my 6 speed a little while to "adapt" to the Amsoil, but its not magic. If its already trashed its probably not going to help that much.
It took my 6 speed a little while to "adapt" to the Amsoil, but its not magic. If its already trashed its probably not going to help that much.
Agreed with EO2K. My 3rd started doing what you're describing beginning of last season. At first it just became not as smooth. But then it got progressively worse. It really doesn't love the 2-3 upshift, but it handles it and feels metallic. Downshifts on track basically grind it every time though for the 4-3 shift. On street I've been double clutching it to keep it happy. I went from Redline to Amsoil hoping it would help, but it didn't make a difference. I finally swapped the trans out this week to solve the issue.
Good luck. I wouldn't expect 3rd to explode on you right away (well, maybe with your power...), but I wouldn't expect it to get much better either.
Good luck. I wouldn't expect 3rd to explode on you right away (well, maybe with your power...), but I wouldn't expect it to get much better either.
Sweet jesus! That was the fixed idler, right? bocabearings.com should have higher speed rated bearings unless you want to go down the path of ceramic bearing madness the Honda guys are using.
It took my 6 speed a little while to "adapt" to the Amsoil, but its not magic. If its already trashed its probably not going to help that much.
It took my 6 speed a little while to "adapt" to the Amsoil, but its not magic. If its already trashed its probably not going to help that much.
As for the transmission, it got way worse with the oil change, so I think I'll swap to the ford stuff, then start shopping for another 6 speed.
I'm also wondering how much my lap times would change with a 5 speed. I'm shifting a LOT on track, and maybe shifting less wouldn't be a bad thing. I don't think my power level (probably 180whp) would crush 5 speeds.
Well I survived another track day... slight belt issue, but otherwise ran great. The other hiccup was my EGR cap (on the header) backed off and left an exhaust leak. Luckily the cap fell in between header flange and the block so I didn't have to find a new one.
Randy Pobst was there and BLEW past me in a 700whp Nissan GTR. It was absurd how fast that car was going.

I have a shitty looking engine bay and I don't care:

Skip to 16:00 for some xtreme farming action! lol
Randy Pobst was there and BLEW past me in a 700whp Nissan GTR. It was absurd how fast that car was going.

I have a shitty looking engine bay and I don't care:

Skip to 16:00 for some xtreme farming action! lol
The EGR nipple on my RB headers completely broke off. Had to emergency weld the hole shut night before a track event. The cap was too much weight for it.
What? No spin?
What? No spin?
Lol. I've NEVER spun this car, I always just gather it up enough to go off track semi straight. haha








