I hate to be the guy just blatantly telling people to perform a simple search so.... yes.

https://www.rx8club.com/series-i-do-.../#&gid=1&pid=1

 

Sometimes just gotta do whacha gotta do

 

Rotary,

I was planning on doing that when I got to it, but hoped someone had a quick answer. I've read up on injectors (to determine what size I wanted), and that was the next step. I do appreciate the link.

Plus I did post in this thread which is more of a chat and discussion, rather than making a new thread.

I've been doing so much reading up to prep for this build, I figured I could ask for a shortcut once in a while!

 

So as I mentioned a few weeks ago, I tried my hand at porting(?)/polishing the Pettit intake. Here are the results (a couple before/after pics, plus showing up in the bend where I couldn't quite get to everything).

For my first ever attempt at this, I think it turned out pretty decent. It's not perfect, but should flow much better than before. It took about 8 hours to get this bastard to where it is, so I'm content to call it quits.

I plan to follow up on the Pettit intercooler (not much to do on this) and the OEM LIM.

 

You need to send it out for Extrude Honing. If you don’t know what that is then google it.

 

I'd never heard of that, thanks for sharing.

My goal was to get whatever flow increase I could through DIY, though. Although the extrude honing does look like it does a nice job, from what I'm finding, the benefit is very low for the cost. For the LIM and Pettit intake, I'm expecting it'd be $900-1000. Seems extreme. Sure, it would probably improve flow 2-3x better than what I did, but mine was just some stone and sandpaper and my time.

Any evidence of reasonable gains anywhere? Extrude honing seems to have been mentioned on this site about 5 times in the last 13 years, and never discussed in depth. Other forums (e.g. Corvette forum - however applicable) seem to indicate it isn't worth the expense. Thoughts?

 

I imagine you are correct with your first statement. I can't see any extraordinary hp increases for the cost on this platform. But then again it probably hasn't been done yet!

 

Well, while I wait for my new BHR ignition kit to come on warranty and my 8 is sitting in my garage immobile, I took the opportunity to do a few things I've been wanting to do - for one, I fitted the longer bolts and spacers for moving my strut tower brace forward in preparation for my supercharger. Secondly, and with a ridiculous amount of work, I managed to get the alternator pulley removed. Damn those things are really on there! Had to buy an impact gun to get it off (which is fine, I've been wanting one for awhile now anyway), but I finally got my new Ryan Rotary Performance alternator pulley installed - it's the last one except for the main crank pulley which will go on with the supercharger.

FYI if anyone is planning on doing this, the alternator pulley nut needs a 24mm socket and it rotates off counterclockwise like a normal nut; I wasn't sure if they were reverse-threaded or something weird like that (never dealt with this before), so I did some Googling beforehand so I wouldn't accidentally tighten it even more.

 

Looks good man! One thing (if you're looking to spend a little more cash) that made a huge difference for engine bay cleanliness for me was getting a BHR under tray to replace that ugly stock air box under tray. Just a suggestion but gets rid of that ribbed undertray that just traps dirt, dust and water.

Pic with my old intake set-up:

 

OtherSyde,

Looks great man! Did your pulleys come anodized? He told me it was too costly to do so they only came in a natural aluminum color. This is fine with my silver/gunmetal theme, but just odd.



RotaryMachine,

I was considering the BHR air box tray, but may mount a second coolant tank for the Pettit kit right next to the OEM expansion tank. Is the tray deep enough on the front to accommodate a tank of that size? I'm worried it angles up too much. In other words, could the OEM expansion tank be moved toward the passenger side 8" and still fit over that tray?

 

Yes! I want a silver one, I think it's $80 or so. It's this LRB one: https://www.ebay.com/i/252060336870


Thanks! And yeah, mine came anodized; He said they could do blue, black, red, or silver. O.o

 

I got mine from BHR, it's a bit more at $125 and it looks like they only have black now:

https://black-halo-racing.myshopify....y-for-the-rx-8

I can't say anything about the ebay one as I've never seen one in person but my BHR one is good thick material and I've had no problems with the coating on it.

 

I have a Pettit kit with the larger Kenne Bell supercharger (Rote8's) that I'm trying to sell. I'm asking for $3K + shipping. I'm located in Melbourne, FL and am able to transport it if you're local.

I'll be parting out the entire car once I get approval from the moderators.

 

AAHHH! Somebody jump on this! I paid $4,850 for mine and it was broken and completely disassembled - I had to pay $750 for a rebuild and track down a bunch of various missing smaller bits, make new seals, etc.! If this kit is complete and has an upgraded blower, then this is an absolute steal!

 

I know, I want to buy it. But that would be stupid to have two superchargers for one car. Sounds exactly like something I'd do.

 

You could buy it and hock your current one for a profit, and then end up with an even bigger beast of a supercharger, if you could muster $3k. Sounds like a pipe dream though. I can't do it because I already painted mine Electric Pearl Blue lol, now I'm stuck with it

 

Trust me, I'm thinking about it. I'm a sucker for stockpiling rare car parts.




On another note, can anyone tell me if the air passageways on the Pettit UIM are larger or smaller than the OEM LIM? I'm still polishing the insides but haven't removed the LIM yet. I'd like to know which I need to enlarge (UIM or LIM) to match the other so I don't waste time polishing the Pettit UIM only to find I need to grind it larger.

 

Wow that turned out pretty well. Makes me feel pretty lazy for never taking mine off. I agree with you that extrude honing it is a bit drastic and expensive considering there really isnt any documented gains for our kit with that process. I really only knew of one person who attempted it and he did exactly what you did. He claimed to feel a difference while driving it but did not dyno before and after to back it up. I rode in his car and it felt faster at 8psi than mine at 11psi but he also had a built Pettit motor.

 

What had to be rebuilt?

 

Keck,
I'm assuming you're talking about Denny/OldDragger? I saw he felt it made a difference, so thought I'd give it a try.

I'm glad you thought mine turned out alright, I had never tried it before. But I'm currently in the middle of a second pass on it to get it perfect, now that I kind of understand the process better. I'll post final pics when I get all the pieces done.

 

I was actually refering to Slvrstreak. Who now that you mention it, might have told me he tried it because OD did it or vice versa.

I am still waiting for the weather to warm up to throw on my summer tires and get it retuned

 

It came to me in pieces, and one of the internal rotors had been scratched up by a piece of aluminum that had been sucked into the unit. I shipped the whole thing off to Kenne Bell to have it refurb'ed to spec. It's why Bennett Built knocked $1,000 off the price. Now it's golden though.

Pics from when I bought it...

 

Someone obviously found great pleasure in making this

 

Update: my polish job now looks less crappy. I still have a couple of passes to go until I'm done. I may work on it more tonight. This better add 50hp.

 

I may be boring you all to death by now, but here's the Pettit intake elbow / supercharger inlet (?) completed. I know it's not perfect, but it's like 9/10 on airflow improvement with 1 being rough cast and 10 being full polish. Not bad for a learning experience and not much cost. I'll do the other pieces soonish.