Thanks brother, but that's kind of the thing, I wanted to see how much more I could get if I freed up the exhaust a little.

So... enter the midpipe! I got a Racing Beat resonated midpipe to replace the cat. I know rotaries are very effected by exhaust flow, but I didn't really understand by how much, so this was going to be a little experiment.




So, how does it suit me.
Well first, noise. At idle, I couldn't notice any real audible difference. The volume is the same, the tone of the exhaust is the same. It is louder when you really start to throttle up, but nowhere near deafening and I'm more than OK with that.
Next, the smell. Eh, not great. I can smell exhaust at every stoplight and I'm not thrilled about it. Frankly, if Sakebomb does relase that 3.5" twin-cat pipe I'd be an eager customer.
Finally, the performance. Welllllllllll... It's good. Too good. I can feel the boost just rocket up whenever I push the throttle, it feels as if its got way more midrange as a result. The problem is that boost shoots up, and over my safety threshold of 17PSI and my ECU cuts spark at around 5500RPM! That's hilariously not good. Even when I tie the wastegate wide open, it still surpasses my safety limit. I can't use the thing! Isn't this racing beat catback supposed to be super restrictive? I was really hoping that the catback would be enough of a restriction to quell any boost creep. No sir, not in my case.

Okay, so I've got options.
I could go back to the Bonez cat.
I could add in a restriction back into the exhaust which is less restrictive than the cat, but just restrictive enough to stop creep.
I could attempt to port the wastegate.

I first bought the 2.5" exhaust restrictor plate from JP3. That... actually worked great. I don't know anything about flow dynamics but was impressed with how much that little restriction effects things. At this point I was peaking at about 16 PSI at 6700RPM with boost control disabled.

So although it worked, I just wasn't entirely thrilled with adding a restriction after going through the trouble to de-restrict the exhaust. It just kept eating away at me, so I took the weekend to pull the turbo and port the wastegate. I looked through ptrhahn's boost creep thread, and found a picture that someone posted of their porting job which seemed like a good medium between taking out the whole T4 divider and just widening the existing area. I decided to use that as my model.
https://www.rx7club.com/single-turbo.../#post12376072
Or at least that was the idea. I ended up getting cold feet before I took out as much material as the example photo. I guess I figured that I could always take out more, even if it would be a pain, but of course there's no adding material back in.

Before:





And the after- wish these pictures were better, but I ended up basically taking out the divider from the end of the wastegate down to the main T4 divider.





No, it's not pretty, it was my first time operating a die grinder and I could have done a better job if I had more patience. But I put it back together, removed the restrictor plate, and with no boost control I peak at about 15.5PSI. Yeah!

In retrospect, I could have removed more material, as 15PSI is my target, so I'm left with no real safety margin should I want to turn the boost down at all. I'll also need to readjust my boost control, as it's current closed loop control is just too slow to react and can still overboost if I'm not careful. I can tweak the PID parameters and make it work, I'll just need some time to do so. But for now I'm just thrilled to be back in control of my boost!

Y'all know I love me some log graphs, so here they are:

WG Not ported, No restrictor plate, No boost control- you can see by the red TPS trace how hesitant I was to go WOT, and of course the moment I did, it safety cut.




WG Not ported, With 2.5" restrictor plate, No boost control




WG ported, No restrictor plate, No boost control

 

Nice update, thx for sharing your results👍

 

AAAAALLLLLLLlright.
Some time has passed.
Some things have happened.

First, some updates. I got a GFB adjustable blow-off which I absolutely love! I pretty much leave it in the loudest mode all the time (which isn't super loud, just sounds good. Looks good too).



I also got the intake piping welded up, and added a bung for the WI nozzle. I wanted it pre-elbow, I sort of figured that might allow for a more even dispersal of mist than if it was in the elbow itself, but that's of course based on absolutely nothing!




I also swapped fuel pumps, got a new Walbro 450. The outlet size of the pump is slightly different to the metal pickup tube size (I think it's 3/8 to 5/16 but can't quite remember). I ended up ordering some tube to hose fittings so both ends were 3/8.


Had some fun with it, took it to a couple autocrosses and took it to the track again on a hot day with my buddy and his turbocharged Corrado.



While chatting he wouldn't stop talking about the benefits of a good turbo blanket and heat wrap. So next thing on my list...




I am immensely suprised with how well wrapping works. It's really helped keep those bay temps down, I can actually touch the LIM now after a drive, where it would be scalding before.

 

After the track I was feeling some judder as I drove normally. It seemed like the symptom of a bad wheel bearing, and the track is hard on those so I changed the front wheel bearings but that didn't solve it.



On a whim I installed some hub-centering rings that I had bought forever ago but never installed. That did the trick! I was very suprised as I had never run them before but now with them the judder is gone.

I also was able to FINALLY get a proper tint and have the old tint removed, as it had gotten really hazy over the years. Kind of a funny story, I called the tint shop that I wanted to use and he asked what the car was and how old it was. Initially told me that because the tint that needed to be removed was so old, they wouldn't take on the job because it takes a massive amount of effort to get it off cleanly. So I said 'thanks anyways' and that was that. Then ten minutes later I get a call back and the owner said "well, why don't you bring it on over and we'll take a look". He checked it out and agreed to do it with the caveat that there would be no guarantees. He ended up doing a phenomenal job, and when I picked it up he said "You know why I called you back right? Because I absolutely love this car."

 

And so...
Then.
This happened.






I know there were some threads a while back about "would you ever let someone else drive your car". Well I was always the kind of person who would gladly do so because I like to share fun things! And I had just gotten so used to how to handle it that I just didn't think too much about it. Well, the driver put his foot down when he shouldn't have, rear end came around and we slid onto an embankment. Nobody was hurt, but the car's scraped up something bad. I feel that this was a total lack of judgement on my part and I feel terrible about it. I want it repaired, and I'm going through my insurance to cover it.

That's why I wanted to get this thread updated, I figured I could share my upcoming experiences with dealing with the insurer. Hopefully there'll be some helpful tips for someone in the future. For now, we'll see what happens.

 

Hard to tell exactly from the pictures but looks totally fixable.

 

I totally agree. My biggest concern is that the radiator seems to be a bit slanted, but most of that other stuff is bolt on (fender, bumper) or just needs repainting. But we'll see what insurance says.

 

The damage included busting my radiator drain plug and popping my passenger side front tire. So I had AAA tow it to my house where I could assess things.
I started the claim (this is through State Farm) and they had a little app where you could check off all of the parts of the car that are damaged. Thing is, it doesn't say how damaged. So you just check off things like 'front quarter panel', 'hood', 'passenger door' etc. The next thing they ask is if the car is driveable. I said no, because of the radiator and tire (and I wanted those to be covered, so I listed them).

This I really think was my first mistake. All of those checkmarks and the non-drivability immediately threw the car into their "probable total loss" category. So their immediate first response was "we can send a tow truck and they'll take it to Copart". I politely declined.

So the problem is that since Covid, they won't send an appraiser to my house for an estimate. They want to take it to a fee-free storage facility and do the estimate there. I do NOT want that, as I have no idea how safe the car will be or if it would maybe get lost (it could happen) or what have you. So my third option is to take it to a shop and the estimator would work with them to determine a repair value. Thing is, the shop I want charges storage fees, which State won't cover. So I think what I might do is see if I got it driveable (I already fixed the radiator, and would just have to borrow a wheel+tire) would that either A) kick the car out of State's "probable total loss" category, or B) lessen or eliminate storage fees.

I'll keep you posted.

 

Sounds like your best option is to get it driveable and take it to the shop for the estimate, and eat the storage fees, if any. I don't see why an estimate should take more than a couple of hours or so to complete, or why it would rack up storage fees for just an estimate. Should be an in & out thing, unless you decide to leave the car with them to do the repairs. Even then, just be upfront with the shop and tell them your insurance doesn't cover storage fees - more than likely the shop will work with you to minimize the storage time you pay by managing their schedule.

Another option is you might try asking the shop if their estimator guy would be able to come to your place for a fee and do the estimate there. That's a reasonable ask if the shop is local.

 

Wow I am really sorry to hear this. It is difficult to stomach, but yes definitely fixable... so it appears.
I would stay away from the insurance as well.

 

Damn.... I hate clicking on a build thread in excitement, only to see these kinds of updates. Sorry this happened man. The damage really doesn't look too bad.

I really dislike how robotic insurance companies can be. Understandable when it comes to a Ford Focus or some other car that most people don't care too much about. It's a different story when you're heavily invested in time, money and emotion in a car. I wish these companies had departments that specialized in these kinds of owners and cars. Would make the process a lot less stressful.

I hope you get it fixed soon.

 

That's why you don't use the commodity insurers; get specialty insurance like Hagerty's. I haven't had a claim, thankfully, but they made it clear they're in the "restoration business" not the "repair business"

 

Yeah really doesn't' look too bad all things considered. Hosing off the dirt will help .

Get the car drivable again yourself, I would just replace the radiator and maybe put the spare on or get a spare wheel that holds air that you can use to drive the car. Probably go ahead and remove the remains of the lip spoiler and that mud guard that's hanging off. Save any receipts.

Once it's safely drivable, then take it up to the adjuster and go forward from there.

All that said, the number 1 rule I tell people when driving my car is only get on the power with the car pointed in a straight line, NEVER in a turn. Yeah it's fun to get on the power coming out of a corner or hanging the tail out a bit, but that's not for them to do . That's something that takes a lot of familiarity with the car. I typically let someone else drive my car with that rule, then we swap drivers and I drive like an idiot to show them what else it can do. By the same token, I don't drive anyone else's cars like it's mine, I'm just not as familiar.

Also "newer" drivers that are used to modern cars with traction control and all that stuff can be in for a rude awakening.

Regardless, keep at it and I know you can get the car 100% again. Worst case pay for it out of pocket and do some of the work yourself.

Dale

 

I have a brand new front fender sitting around, if youre local you can have it for cheap