70MM Throttle body upgrade, opinions. - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 04-21-2016, 03:30 PM   #21
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,372
Total Cats: 1,333
Default

Quote:
Originally Posted by Madjak View Post
Yes but restrictive or not, the main reason to replace the stock throttle body is for insurance against shaft failure taking out an expensive built engine. I personally would not bother with throttle body from Skunk2 as they all have major design flaws. The S90 that I am recommending is a good balanced option in terms of quality and cost... There is even a 55mm S90 for those wanting to keep close to stock sizing.
One small problem: S90 does not make a Miata throttle body. The Skunk2 has issues, yes, but they are all easily rectified with a little knowledge and 5 minutes of preparation before installation. I broke a throttle return spring on an early production part, but I've had absolutely no issues with the replacement Skunk2 TB on Rover over the last ~5 years.
Savington is offline   Reply With Quote
Old 04-21-2016, 06:50 PM   #22
Junior Member
 
Join Date: Jan 2015
Posts: 272
Total Cats: -22
Default

I love how this is some kind of closely guarded secret...
Alternative is offline   Reply With Quote
Old 04-21-2016, 08:23 PM   #23
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Apr 2008
Location: Phx, AZ
Posts: 357
Total Cats: 1
Default

Quote:
Originally Posted by Savington View Post
One small problem: S90 does not make a Miata throttle body. The Skunk2 has issues, yes, but they are all easily rectified with a little knowledge and 5 minutes of preparation before installation. I broke a throttle return spring on an early production part, but I've had absolutely no issues with the replacement Skunk2 TB on Rover over the last ~5 years.
I know S90 doesn't make one for miata's but I have to change my flange regardless because it's a 1.6L car, so nothing is going to just bolt on for me. So if it's a DSM throttle or a 70mm from BEGI or a S2 I don't think it will fit on the current 1.6 flange.

Also, Did you guys test between a 52-65-70 mm TB as far as power gains? I was thinking maybe with my manifold and turbo setup I might see some benefits some where as far as power goes.
theshdwconspracy is offline   Reply With Quote
Old 04-21-2016, 08:31 PM   #24
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,205
Total Cats: 2,586
Default

Quote:
Originally Posted by theshdwconspracy View Post
Also, Did you guys test between a 52-65-70 mm TB as far as power gains? I was thinking maybe with my manifold and turbo setup I might see some benefits some where as far as power goes.


no matter how you re-phrase the same silly question, the answer remains

you know what you should test with?

a higher flowing engine.
18psi is offline   Reply With Quote
Old 04-21-2016, 08:37 PM   #25
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Apr 2008
Location: Phx, AZ
Posts: 357
Total Cats: 1
Default

Quote:
Originally Posted by 18psi View Post


no matter how you re-phrase the same silly question, the answer remains

you know what you should test with?

a higher flowing engine.
I was just curious what all people tried out there and if there were any results. If not, I'll just throw the stock one back on for the moment before going through all the trouble of re engineering my whole manifold/throttle body/swirl pot/car, just to fit a stronger throttle shaft.
theshdwconspracy is offline   Reply With Quote
Old 04-21-2016, 08:43 PM   #26
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,205
Total Cats: 2,586
Default

but you see, that's a concern for your car: the shaft on the stocker will likely break at some point, especially the way you use the car. if you cracked your manifold several times, the tb shaft will likely not last too much longer and can take out your engine as it goes.

this is not as much of an issue for a street car.

you just need to understand that its a reliability mod, not a power mod. not for your engine
18psi is offline   Reply With Quote
Old 04-21-2016, 11:53 PM   #27
ʎpunq qoq
 
Join Date: Jan 2014
Location: Western Australia
Posts: 502
Total Cats: 100
Default

Quote:
Originally Posted by Alternative View Post
I love how this is some kind of closely guarded secret...
Issues are:
Sticky throttle is common... I think due to the next point
Movement in the throttle plate when partially open (ie sideways movement in the bearings)
Throttle return spring is too weak (ie return force) and the locating tag can break off
Idle adjustment screw doesn't offer enough idle adjustment so you have to use the throttle stop. (which also changes TPS)
Throttle stop bolt can come loose unless you loctite it or put on a better locking nut, or do it up very tight.

On the non Miata throttle bodies:
TPS locating tab is held on by the tiniest of screws. High reving motors can vibrate it loose.

Not all the above issues effect every throttle body. Some are fine and have no issues out of the box, but all the above are fairly common if you search. There is a good reason the Skunk2 products are referred too as Junk2 on the Honda forums. The Miata specific Skunk2 throttle body is actually one of their better throttle bodies...
Madjak is offline   Reply With Quote
Old 04-22-2016, 02:36 PM   #28
Supporting Vendor
 
KMiata's Avatar
 
Join Date: Sep 2012
Posts: 444
Total Cats: 145
Default

I wouldn't worry about throttle modulation with a 70mm. That's all we run on the K series cars, or 74mm, and they all feel fine. Domestic guys have been running 90mm+ forever.

Edit: I can also vouch for Skunk2 throttle bodies. That's all we use, and I assume their Miata piece is similar quality.
KMiata is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Begi s4 overboost > looking for advice. kiladonut Prefabbed Turbo Kits 64 04-25-2016 02:51 PM
S13 240SX throttle body on a 1.6 Rothko General Miata Chat 10 04-19-2016 11:51 PM
Low RPM signal, no spark macman2212 MEGAsquirt 16 04-10-2016 12:49 PM
6 Rib Crank Pulley?? stuiedaman Supercharger Discussion 12 04-09-2016 01:37 PM
Springs, NB Throttle body, NA 1.8 Test Pipe skipstr Miata parts for sale/trade 2 03-31-2016 11:35 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 01:30 AM.