Diagnosing suspension setup over the internet rarely works out. But, you describe spinning and hooking up. It maybe inside wheel hop due to the differential moving around. I haven't read your whole build thread but you might look at firming up the differential mounting; start with stronger differential bushings and a transmission brace, then add a differential brace, and as a last resort add the Mazdaspeed powerplant frame.
https://cimg0.ibsrv.net/gimg/www.rx7...4a76659ac5.jpg

That's an interesting thought for sure. I had assumed the wheel spin was that the inside tire was becoming unloaded and spinning with the torsen diff. I'm most of the way to the photo above in that I have superpro diff bushings and the banzai trans crossmember. (also have the same extra capacity trans and diff options in the photo) I was going go try to run Jim's 2-in-1 diff brace, but it wouldn't fit with my exhaust for some reason and I felt it was overkill for what I was doing. I'd think with the diff and trans brace you probably don't need the upgraded PPF. Perhaps I can find a cheap diff brace to try out, or otherwise I'll see if I can put the go-pro on the outside of my car to see if I can capture the wheel spin at all and narrow that down too.

I would (will) just put in a Kaaz or even better OS Giken 1.5 way differential.

The FD is narrow car and when you put sticky tires on it will unload the inside wheels.

In Japanese tuning it would be quite rare to use a stock differential in any raced car since they are compromised for comfort/driveability.

An aftermarket Torsen with a much higher bias ratio would be fine, but it is easier to put in a quality multi-plate clutch type that has a very broad range of engagement between locked and open that you are operating in.

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I still think it would be great to work on the suspension to get as much droop as possible.
I felt the Ohlins limited droop even with 11k spring rate compared to stock suspension.

If you upped the spring rate without allowing the spring to be loose on the lower mount or held in place with a tender spring you have further reduced the droop travel of the Ohlins.

I agree a clutch type diff is the end solution but it's not in the budget this year. Also I want to make sure I have cooling sorted so I'm not just cooking a fancy expensive new differential.

My rear Ohlins have stock springs with the factory recommended 2mm preload. I'm not sure how you would get more droop travel out of them as-is (other than that 2mm). I think it's just a limitation of the Ohlins design/length.

Time for the long stroke Ohlins design SakeBomb just released.

I just picked up an OS Giken 1.5 Way Diff and using a Greddy Diff cover that holds extra fluid, is aluminum and has bungs on it already for a cooler.
See my build thread for pics it's going in next week.

I saw the long stroke versions for the S2000, but are they making one for the FD?

I'll have my cooler setup done by the end of July. Pump and cooler are mounted, but I need to run lines and electrical.

Also my apologies all of my photo links are broken. You might have noticed but Photobucket changed their terms of service this month and now are holding account owners hostage...the only way to make all of my links work again? Pay $400/year for an upgraded account. WHAT RAGING ASSHOLES!!! I'm still figuring out which host to go with from here and it'll take me some time to get the back posts updated if at all possible since I can't edit the posts on this forum.

Flickr. Never looked back

Any updates on the build?

I've been driving it....and fixing it....and driving it!!! I've done 3 more events since the last update, also put together and running a diff cooler setup, and got some more time on the sticky tires which are awesome fun.

I was hoping to update the old broken links in this thread and update with the new stuff, but have not had anywhere near the time needed. I'll try to at least get the forward stuff going.

Just got back from a weekend at Watkins Glen with 3 days of great weather and was able to run a time there even better than I was hoping for. I'll see if I can get this thread up to date this weekend perhaps on the holiday or something.

Diff cooler is a PIA mod but it is needed for fast laps :icon_tup:

What was the lap time and post up some video :nod:

I would like to see pictures of the diff cooler you made.:nod:

I was hoping I could delay enough to get the thread up to date and not post out of order. BUT...you're always willing to help with good advice, so just for your Fritz I'll do it..haha.

lap was a flier for me on the Pirelli tires. 202.8 I'm quite happy with it. There's always more on the table, but for my 2nd time there and only 3rd session on sticky rubber I think it's pretty respectable.

I'll have to admit that Andy called this out last year pretty much spot on! I was able to bank a few low 2:04s over the weekend as well. I figured the car had a 2:03 in it for sure and it just worked out better. I think I'll be hard pressed to do better, but that's why we always go back right?

Also, are others able to see the old pictures in the thread? Did the board fix the photobucket issues? I'm seeing them, but not sure if others do or not.

Straight up sick lap time :)

Super smooth also :icon_tup:

Thank you sir, I appreciate it especially from you. The lap has some gritty moments like I'm staying flat all the way from apex of 1 thru the esses and back straight. That one I had to grit my teeth to force myself to do. I could go harder into places like 6, but as you know that track has some pretty harsh consequences for mistakes

Also getting fuel starve with the slicks at much higher fuel levels. You can see it happen in 6 and 9 in the video which drives me crazy. Gauge reads 3/8 tank which after a few laps of sloshing means there's really like 1/2 tank in there. On the Nittos though I can drive it down past 1/4. So I'll have to consider another option this winter I suppose.

Of course in the natural trend of things as I get faster so does the yellow bunny I chase. He got the 996 GT3 down to a 201.5!....dang...I'm not catching that one at my current power level I don't think.

Damn man, that's a great time, I'm going to have to lower my target :-0

Does the new asphalt help the times out?

P

I don't have any direct comparisons because I never drove on the old asphalt, but my understanding is that yes, it should help times. The new surface is pretty great honestly. What was unexpected is that on the track walk this past weekend I noticed that there are already little divots/chips in the surface. I'm not sure what's expected there, but it's not as marble smooth as it feels like it is when you're driving on it. Overall though it's got good grip without being overly hard on tires, so that's pretty much as good as it gets to me.

You'll have to let me know what sort of MPH you see on the back straight. I think where the stock twins are really limiting me is that above about 130mph the car really slows acceleration. I was getting to the low 140-s on the back straight whereas the GT3 would hit 150-151.

Despite my time the 2:02 from the RX-7 was the lap of the weekend in my opinion. I'm pretty proud of that one for you. Our power to weight is pretty similar BUT we are talking about a track where corner speed is key and you ran that lap in a car with no aero at all. Stick a wing and splitter on that thing and the number would be epic.



...but of course I'll add something to the GT3 to try to keep it out front :-)

What size nt01 tires do you run?

LOL......great lap times from you both.

Once he goes single you'll really have to work hard hehe :egrin:

PS Pete and I need to get together at the track sometime with you guys. We would rain down terror on whatever group we ran in :egrin: I seriously suspect the 2.01 is close to the fastest time a street 6 GT3 has run at watkins and the same for the FD. The FD being on twins though is what makes that lap time EPIC!!!!

275/35-18. They're tall as crap and a compromise for the car as noted previously in the thread, but they match up to the slick sizes I'm running so I can have one setup for both tires.

Hopefully we'll justify making a trip down to VIR in the next year or 2 and then you and Peter can beat up on us with your years of experience there. Or next summer we can meet up at Watkins. If you guys get the desire to come to Mid Ohio just let me know as we're there all the damn time..haha.

Thank you, I'd enjoy running with you guys if we can make it work. I'll let Chris sort scheduled for next spring and hopefully we can make it work.

As a rule, there's always someone faster...and in my case I know a guy with a 996 GT3 that's been in the very high 1:58 range. His car is fully gutted and 250lbs lighter than my car plus makes more power so I doubt I'll get him but I know based on data from this past weekend my car will get below 2:01. Just a matter of sacking up and doing it. I'm not aware of any other 996's within range of me currently though so that's a nice confidence booster. I could probably stand to lose 30-40 lbs off of my fat ass and that would help too. My seat broke the last session of Sunday and I think that's a sign to get on the damn treadmill.

...and I'm def. in trouble if Chris goes single turbo and or full aero

Yep a street car isn't going to compete against a similar prepped race car especially if it's lighter AND has more power.

Seat broke...........:lol: