Stian's 1992 trackday weapon - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Build Threads Building a motor? Post the progress here.

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-28-2011, 09:16 AM   #21
Newb
Thread Starter
 
Join Date: Nov 2004
Location: Bergen, Norway
Posts: 28
Total Cats: 0
Default

Quote:
Originally Posted by hf-mx5t View Post
obviously this guy has also been visiting the garage where inglar and myself work on our mx5's not often 3 owners of 400ish whp mx5 get together in a small country like norway. im not sure if theres any more of us

cool to see your project here aswell Stian.. if you fix the issues we discussed, the car will be fast and fun again..
Yeah! Thanks a lot to Harald & Inglar for the garage-tour and R&D advices... Some insane projects coming to life in that garage! You guys are completely nuts... Very impressive indeed!!

Quote:
Originally Posted by Savington View Post
Our brakes are MEANT for excessive track use. Add our duct kit and you will never have fade issues, ever. Our turbocharged shop car holds the Miata lap record at Buttonwillow 13CW using our 11.75" kit.
Sounds great! I will see how much I have time for until next season, but most probably I will stick with the existing setup for next year, and then upgrade (downsize) the brakesystem for next year. But lets see what happens... I will at least add a bias-valve and a larger master cylinder.

Quote:
Originally Posted by falcon View Post
Sweet you're from Bergen. I almost went there a month ago so. Perhaps in the spring once it warms up a bit
Let me know if you make it over and I will take you on the grand-tour of town I did go to Vancouver last year. Great place & awesome skiing at Whistler.

Quote:
Originally Posted by Faeflora View Post
Nice. Details on intake manifold please?
Also, please go gt35! 500hp or bust!
It's a custom modified Greddy aftermarket intake for the Nissan 200sx. The 65mm throttle body comes from the Nissan Primera GT ( Infiniti G20 in the states?). The intake was adapted to fit the Miata-engine by a previous owner, so I can't tell you too much about it I am afraid. I can send some close up shots if you want...

Hehe - I am already wondering if I can live with the delay in spool from the GT30 vs the 28-series, so I am not sure if the GT35 will help I am not aiming for max top performance (only) - I want something that gives good throttle response on track with some sort of reliability... I am sure 500whp will be more bust than reliable.

I've done some flowcalculations of the various turbochargers I've been debating, and will post them here shortly to get your feedback on it... Maybe I should do one for the GT35 too - just for the hell of it
stian is offline   Reply With Quote
Old 11-29-2011, 08:57 PM   #22
Newb
Thread Starter
 
Join Date: Nov 2004
Location: Bergen, Norway
Posts: 28
Total Cats: 0
Default Flowcalculations: GTX2867R vs BorgWarner EFR6258

I've done a bit of calculations, according to Graham Bell's formulas, in order to better understand what would be the better turbo to select for my project. I calculated for 15psi & 22psi from 3600-7200rpms, then I did one for 25psi @ 7600 and one completely over-the-top at 30psi.

After going comparing all the compressorcharts, there are a few of the smaller (pre GT30) turbos that looks very promising. One is the new Garret GTX2867R. The first batch of these turbos are shipping very soon, so I sent some emails to ATP to get their opinion about it and they were extremely enthusiastic. It is promised to spool as well as the 2860RS but will deliver a whole lot more on the top end. See the comparison charts here. They could also ship it with a T3-turbine that could fit my existing downpipe. Here's the flowchart:



Not too bad at all!! No issues with surge and even up to the higher boostlevels it operates inside the most efficient area of the compressor, hitting the sweepspot at the end of the RPM-ranges. Would be awesome to see full boost closer to 3000rpms and yet reaching well above 300whp! I am a bit surprised that this turbo has not been mentioned either here or at M.net! Am I missing something here - apart from the fact that it's a fairly new device..? Will be very interesting to see how it compares in real life, once we see the first builds on the dyno.

The BorgWarner EFR6258 also looks very very promising. This seems to be the one to beat - at least when it comes to delivering at the lower rpm-ranges. Will be interesting to see once more people finish their builds and show some dynoplots with higher boost than the 12psi that "fresh38" was producing. Even then he produced 270rwhp on a more or less stock engine!!! Very impressive.



Edit: My first calculations were a bit off on this turbo, as I didn't scale it correctly. This now looks even better! Seems like the compressor is able to give 20psi all the way from 2800rpm to redline

Some other alternatives are also attached with overlayed flowcalculations, including the suggested GT35 that for sure will fit really well

To be continued...
Attached Thumbnails
Stian's 1992 trackday weapon-flowcalc_gtx3071.jpg   Stian's 1992 trackday weapon-flowcalc_gtx2867.jpg   Stian's 1992 trackday weapon-flowcalc_gt3582.jpg   Stian's 1992 trackday weapon-flowcalc_gtx3076.jpg   Stian's 1992 trackday weapon-flowcalc_gt3076.jpg  

Stian's 1992 trackday weapon-flowcalc_gt3071.jpg   Stian's 1992 trackday weapon-flowcalc_gt2876.jpg   Stian's 1992 trackday weapon-flowcalc_gt2871_v4.jpg   Stian's 1992 trackday weapon-flowcalc_bw6258.jpg  

Last edited by stian; 11-30-2011 at 09:31 PM. Reason: Wrong flowcalculation for BorgWarner turbo
stian is offline   Reply With Quote
Old 01-31-2012, 08:34 PM   #23
Newb
Thread Starter
 
Join Date: Nov 2004
Location: Bergen, Norway
Posts: 28
Total Cats: 0
Default Questions about RX7 "hybrid" gearbox

A while since my last post since the car was taken apart to weld some exhaust leaks and make a proper threaded fitting for the EGT sensor which the previous owner had made a half assed attempt to weld into the turbinehousing

Has since then been waiting for the snow and ice to clear off the road so I could take it for a spin. Today we had -6c (21F) but the roads were at least dry enough to brave a little testdrive. The fixed leaks was successfull and I got 2-3psi more now than before, so it pulls way too hard for the roadconditions to give me any traction. Turbolag is still HUGE, so the damaged dinosaur of a T3 must go. The quest for the proper replacement solution continues...

Now, I have a few questions regarding my hybrid RX7 FD3S tranny. The previous owner who fitted it, cut and welded a Miata bellhousing to the RX7-box and made custom fittings to bolt it to the PPF:




First of all the speedocable has snapped so I need to replace it. It looks like a standard Miata cable, right? So I guess they must have changed the drive-gear inside the transmission to make it read correctly on the Miata... Anyway, the sharp bend they made to the cable, probably caused increased friction so that it eventually snapped. Will see if I can get one of those angle-adapters so it does not happen again. Anyone who has one on the shelf?




Last question is related to a rattling noise in idle. The audio comes and goes as I press the clutchpedal:

What could be causing this? Throwout bearing? Transmission bearing(s)? Clutch fork touching something it shouldn't?
Attached Thumbnails
Stian's 1992 trackday weapon-img_0073.jpg   Stian's 1992 trackday weapon-img_0077.jpg   Stian's 1992 trackday weapon-img_0085.jpg   Stian's 1992 trackday weapon-img_0110.jpg   Stian's 1992 trackday weapon-img_0111.jpg  

stian is offline   Reply With Quote
Old 02-02-2012, 02:24 PM   #24
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,247
Total Cats: 291
Default

I vote the latter- in the bell housing- like rubbing diaphragm springs. Don't you have some places to peak through into the bell housing? fork boot maybe? That's where I peered in with one of those flexible LED lights to see my clutch disc in pieces. I assume nothing has changed in (driveline) drivability.
m2cupcar is offline   Reply With Quote
Old 05-01-2012, 08:00 PM   #25
Newb
Thread Starter
 
Join Date: Nov 2004
Location: Bergen, Norway
Posts: 28
Total Cats: 0
Default

Choice of turbo has been made, and I will attempt to go smaller and see what can be done with the GTX2863R with .63 A/R T3 hotside. Installation will hopefully happen within the next 2-3 weeks...

Also picked up oilcooler, tons of AN-couplers/hoses and some other bits and pieces.
stian is offline   Reply With Quote
Old 08-14-2012, 12:20 PM   #26
Newb
Thread Starter
 
Join Date: Nov 2004
Location: Bergen, Norway
Posts: 28
Total Cats: 0
Default

The new GTX2863R turbo is in place - and has been for a while now... Sofar I am running more or less on my old map, so it's far from optimal but things are certainly working much better than before!! I now have full boost (18psi for now) at 3800 which is 1500rpm sooner than the old Turbonetics thing. Also no more oilsmoke and noises. However, I am wondering why my boost curve rises so slowly from 1750 to 3000? Especially compared to the Cueball's 2860-setup, which seems quite similar to the hardware I'm running... Could it be cam's that needs less overlap?

I am going to the dyno later this week to get it properly tuned, so will post back the results and add my boost-plot once its done.
Attached Thumbnails
Stian's 1992 trackday weapon-spooldata_log-fra-autronic__sammenlignet-med-gammel.jpg  
stian is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Raleigh: Fiberglass headlight scope, 1.6L ECU, AFM, Hardtop latches, more bigmackloud Miata parts for sale/trade 13 09-22-2017 01:34 PM
Nuke Mars! Joe Perez Current Events, News, Politics 8 09-30-2015 05:41 PM
VR6 to Miata Swap ScrapinMX5 Meet and Greet 8 09-28-2015 02:04 PM
00/99 IAC into 92 wiring harness AdoboMiata MEGAsquirt 4 09-22-2015 03:32 AM
FS: Parting out 1990 Miata [92 motor] blaque Miata parts for sale/trade 26 06-09-2008 04:12 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 06:33 PM.