Andy Hollis' One Lap Miata (K24 Honda power) - Page 13 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 11-09-2015, 11:31 AM   #241
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Quote:
Originally Posted by Savington View Post
I also saw none of the drop-off you talk about in the Rival S, even over long enduro stints (2hr).
We saw drop-off in the RE71R during the GRM test, but not the Rival-S. That was on my CRX.

On the Miata with 225 Rival-S, I am cooking the rear tires after a few hard laps. Backing off brings them back, though. Saw the same thing at NCM on the west course (not full). These are both shorter courses with lots of turning Tracks with longer straights would likely provide more cooling. For example, I had no issues at COTA.
AndyHollis is offline   Reply With Quote
Old 12-31-2015, 09:22 AM   #242
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Getting back to this...big stuff coming soon, but here's a snippet that will helps others doing this same swap...

The K-series MAP sensor is designed to fit in a hole that is pretty deep, sealing against an o-ring. If the metal is thin, the o-ring does not seal perfectly. The metal in the GE intake is relatively thin.

I had a problem start to surface recently at COTA when the car began running super rich during the last session. I limped it home and eventually discovered MAP readings that were a little lower (less vacuum) than I had been seeing. I fixed it by installing a second o-ring around the base of the sensor “stub” and using a washer on the bolt to match the o-ring height. This did two things: 1) it set the standard o-ring depth shorter, and 2) what the standard o-ring does not seal, the second one does. I also put some sealer on the bolt threads since that penetrates the manifold as well.

Attached Thumbnails
Andy Hollis' One Lap Miata (K24 Honda power)-f77af8ab-e7ef-44d3-a99d-a6836ff60f57_zpssz2vjtmn.jpg  
AndyHollis is offline   Reply With Quote
Old 01-01-2016, 08:39 AM   #243
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Happy New Year!!

Remember this?

Quote:
Originally Posted by AndyHollis View Post
I'm having trouble getting all the power down even in 3rd gear coming off corners. 225 Rival-S on 9's can't handle 300hp in 3rd unless you are perfectly straight. And I am going through rear tires at a prodigious rate as a result. On r-comps, the solution would be a no-brainer...but One Lap rules say 200tw.

So...time to do "what they say can't be done".
Solution => We are fitting 285/30-18 Bridgestone RE-71R's on 11's by tubbing the inner fenders and using a wide-body kit from DG Motorsports (AWR source).

This is a new size for that tire, due 3/1. In the meantime, we'll use 255/40-17 on 10's.

Proof of concept comes from the Wootton SSM autocrosser seen below in black using the same flare kit around 285 Hoosiers in front, and 315's on 12 in the rear. Rules disallow tubbing for that car, so he makes up for the 25" diameter by jacking up the perch height an inch. He's local, so I have studied it carefully.

The white car (Steve Garnjobst's XP autocrosser) is an example of a no-rules solution with tubbed inners. Not pretty, but very functional. Allows the suspension to have the same travel as with the typical 23" tall tire. You'd still have the other 1" higher ride height from chassis to ground, so Steve also moved all of the suspension pick-up points up an inch to get that back too. We will not be going that far...at least at this point.

While I could do this myself, it's being farmed out to someone who can make it pretty...since this car will see some more Optima event exposure in 2016. Apex Auto Works in Houston will do the fab. They do great race car construction, as well as paint and body...and vinyl is what they originally cut their teeth on. So we have many options on final finish. They have obtained a donor chassis (seen here in red) to cut out inner fenders that will then be blended onto mine about an inch or so up. Should make it look much more stock appearing.

Glass parts are built and enroute. Car goes under the knife in a week, with the goal to display it the end of January at the GRM tent at the Rolex 24 in Daytona.

PS: For non-200tw events, you can imagine the possibilities of slicks that we can run with so much room for activities.
Attached Thumbnails
Andy Hollis' One Lap Miata (K24 Honda power)-img_5477.jpg   Andy Hollis' One Lap Miata (K24 Honda power)-img_5478.jpg   Andy Hollis' One Lap Miata (K24 Honda power)-2011-10-25_21-35-42_533.jpg   Andy Hollis' One Lap Miata (K24 Honda power)-rear-inner-fender-trunk-passenger.jpg   Andy Hollis' One Lap Miata (K24 Honda power)-apex1.jpg  


Last edited by AndyHollis; 01-01-2016 at 09:06 AM.
AndyHollis is offline   Reply With Quote
Old 01-02-2016, 12:13 PM   #244
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Surprised the white car didnt move the shock pickup points as well. Or at least move their tubing most of the way to the shock top mounting holes, thats where the worst of the interference already is with fitting manly tires.
Leafy is online now   Reply With Quote
Old 01-12-2016, 01:36 AM   #245
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Project Big Wheel has begun.



That moment when somebody takes a sawzall to your pride and joy...



After the tubbing and flares are complete, we'll be converting to a 5x114.3 pattern using this method: MiataV8 Conversion: Five Lug Conversion

That gets a better bearing in the front, and a super easy five-bolt hub swap in the rear. I'm also investigating a couple of other front hubs to reduce the machining effort, but the FD RX7/Probe/MX6 hub with sleeve is a good known quantity.

That decision was made when we weighed Wootton'scustom 4x100 CCW wheel and discovered it was 26 lbs. Instead, we'll be using an off-the-shelf Enkei RPF1 18x10.5 ET15 5x114.3 that weighs 19 lbs for half the price, and available with no waiting.

Meanwhile back at the ranch...Andrew Keisler is working on a five-lug version of his front drop spindles for me.
Attached Thumbnails
Andy Hollis' One Lap Miata (K24 Honda power)-17433785-45c6-4bc8-b6c3-7016094b68c8_zpszxy6x83o.jpg   Andy Hollis' One Lap Miata (K24 Honda power)-31ab6eff-312f-4d83-85ef-682fb6557f60_zpsn5x7vmvr.jpg  

Last edited by AndyHollis; 01-12-2016 at 09:26 AM.
AndyHollis is offline   Reply With Quote
Old 01-12-2016, 12:11 PM   #246
Supporting Vendor
 
KMiata's Avatar
 
Join Date: Sep 2012
Posts: 444
Total Cats: 145
Default

Quote:
Originally Posted by AndyHollis View Post
Project Big Wheel has begun.



That moment when somebody takes a sawzall to your pride and joy...



After the tubbing and flares are complete, we'll be converting to a 5x114.3 pattern using this method: MiataV8 Conversion: Five Lug Conversion

That gets a better bearing in the front, and a super easy five-bolt hub swap in the rear. I'm also investigating a couple of other front hubs to reduce the machining effort, but the FD RX7/Probe/MX6 hub with sleeve is a good known quantity.

That decision was made when we weighed Wootton'scustom 4x100 CCW wheel and discovered it was 26 lbs. Instead, we'll be using an off-the-shelf Enkei RPF1 18x10.5 ET15 5x114.3 that weighs 19 lbs for half the price, and available with no waiting.

Meanwhile back at the ranch...Andrew Keisler is working on a five-lug version of his front drop spindles for me.
This is just awesome. Can't wait to see the final product.
KMiata is offline   Reply With Quote
Old 01-12-2016, 12:38 PM   #247
Elite Member
iTrader: (17)
 
Join Date: Aug 2007
Location: Fort Myers, FL
Posts: 2,791
Total Cats: 130
Default

With the traction problem resolved, the next logical step is more power right? Love this build, I can't wait to see how it'll stack up at this years One Lap.
pdexta is offline   Reply With Quote
Old 01-12-2016, 12:48 PM   #248
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Quote:
Originally Posted by pdexta View Post
With the traction problem resolved, the next logical step is more power right? .
Nope...bigger brakes.

I suspect that the additional leverage of the 25" tall tire (vs 23) will overwhelm the 11.75 front rotor/Wilwood combo. Hope not, but it would not surprise me.

I have to do different hats anyway for the five-lug conversion...
AndyHollis is offline   Reply With Quote
Old 01-12-2016, 02:33 PM   #249
Junior Member
 
Join Date: May 2012
Location: NYC
Posts: 251
Total Cats: 38
Default


Attached Thumbnails
Andy Hollis' One Lap Miata (K24 Honda power)-7qawas9.gif  
dasting is offline   Reply With Quote
Old 01-12-2016, 04:53 PM   #250
Elite Member
iTrader: (41)
 
Join Date: Jan 2006
Location: Seabrook, TX
Posts: 2,409
Total Cats: 19
Default

Richard does good work. I have had 3 cages built by him and all turned out well made. Based on the builds I have seen him and Ronnie do, the car is in good hands.
rharris19 is offline   Reply With Quote
Old 01-12-2016, 07:21 PM   #251
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,187
Total Cats: 2,583
Default

Quote:
Originally Posted by AndyHollis View Post
Project Big Wheel has begun.


That moment when somebody takes a sawzall to your pride and joy...


.
faeflora just got a random erection
18psi is offline   Reply With Quote
Old 01-14-2016, 04:43 PM   #252
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

God damn Honda kids finding out about Miatas and ruining them with their big rims and VTECs.

Ugh.
Dunning Kruger Affect is offline   Reply With Quote
Old 01-14-2016, 04:47 PM   #253
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

aidandj is offline   Reply With Quote
Old 01-14-2016, 06:15 PM   #254
I take big bites
iTrader: (1)
 
turbofan's Avatar
 
Join Date: Sep 2010
Location: Hurricane, UT
Posts: 6,924
Total Cats: 526
Default

Serious question: Is this all about brakes? Why would you go up to a 17" wheel when there are 15X10s and such available at much lower weight?
turbofan is offline   Reply With Quote
Old 01-14-2016, 06:16 PM   #255
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

Its about width and tire selection. Nobody makes anything bigger than a 225 in sticky street tires.
aidandj is offline   Reply With Quote
Old 01-14-2016, 07:37 PM   #256
Elite Member
 
Join Date: Oct 2011
Location: OKC, OK
Posts: 2,650
Total Cats: 76
Default

I see my guess was too close on the FB page?
z31maniac is offline   Reply With Quote
Old 01-14-2016, 08:04 PM   #257
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
God damn Honda kids finding out about Miatas and ruining them with their big rims and VTECs.

Ugh.
It boggles my mind that a performance-oriented carmaker like Mazda (Zoom-Zoom) has not yet produced a dual-lobe cammed engine.

Quote:
Originally Posted by aidandj View Post
Its about width and tire selection. Nobody makes anything bigger than a 225 in 23" tall sticky street tires.
^^ This (clarified in bold).

One Lap uses a 200tw restriction as one of its few rules. You also have to finish the entire event on one set of tires...with 2/32nds remaining.

The fastest 200tw tires right now for a 3-lap time trial are the Rival-S and the RE-71R. The former comes in a 225/45-15, but not the latter. Further, the Rival-S is not good in deep water, whereas the RE-71R is amazing (see my GRM deep water testing sidebar in the track test article).

So ultimately, I wanted to find a way to run the RE-71R in sufficiently large enough size to put all the power down in 3rd, and with enough meat to not wear out during the week. 255/35-18 (or 255/40-17) would probably be enough, but with just a little more effort, I can also fit the new 285/30-18. Both are close to 25" tall and require massive fender work. I have the 255's on the way now and will compare them to the 285 once those are released. I'll run whichever is faster.

Last edited by AndyHollis; 01-14-2016 at 11:22 PM.
AndyHollis is offline   Reply With Quote
Old 01-15-2016, 01:30 AM   #258
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

Quote:
Originally Posted by AndyHollis View Post
It boggles my mind that a performance-oriented carmaker like Mazda (Zoom-Zoom) has not yet produced a dual-lobe cammed engine.
I mentioned it a bunch on mnet when everyone was whining about "y only 155hp! honda makes 200hp out of 2 litre!!", but it's worth repeating that Honda's the largest engine manufacturer in the world, had an F1 team and is getting back into developing F1 motors, and has a massive motorcycle business with the history to go with it, as well. Not to forget that Honda is one of the larger auto manufacturers and Mazda is comparatively quite small (and fragile when they keep betting the farm on the rotary).

They just have the R&D and history that Mazda doesn't. The MZR/L series is undeniably a good motor, especially the DISI; however, the K series motor is a contemporary equivalent, and it's just heads and shoulders above Mazda's powerplant efforts.
Dunning Kruger Affect is offline   Reply With Quote
Old 01-15-2016, 01:37 AM   #259
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

This project is awesome, and i'm sure the grip will be amazing. But damn, 18's look ugly as sin on a miata.

Personal preference.

I would still rock them for the grip

Also in for handling feedback, as historically heavier wheels means a worse ride/handling.
aidandj is offline   Reply With Quote
Old 01-15-2016, 08:30 AM   #260
Junior Member
Thread Starter
 
Join Date: Nov 2006
Posts: 284
Total Cats: 149
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
I mentioned it a bunch on mnet when everyone was whining about "y only 155hp! honda makes 200hp out of 2 litre!!", but it's worth repeating that Honda's the largest engine manufacturer in the world, had an F1 team and is getting back into developing F1 motors, and has a massive motorcycle business with the history to go with it, as well. Not to forget that Honda is one of the larger auto manufacturers and Mazda is comparatively quite small (and fragile when they keep betting the farm on the rotary).
Toyota has also had dual-lobe cams for over a decade and a half. So there's two versions that Mazda could have copied.

Of course, the "right" answer is the infinitely variable BMW Valvetronic.

But we're getting a little off-topic now...
AndyHollis is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
elesjuan's mediocre 95 Miata adventure (google fiber edition) elesjuan Build Threads 8 02-16-2016 09:36 PM
Turbo 1995 Miata Low mileage Clean Tekel Cars for sale/trade 29 02-05-2016 05:16 PM
starting issue Johnny Tater Engine Performance 3 09-23-2015 07:10 PM
Foreign powered NB for NASA ST3 and/or E0 d k Race Prep 44 09-15-2015 11:59 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:05 PM.