Looking for opinions - T25/28 or T28 FM3 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 06-24-2006, 04:43 AM   #1
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2005
Location: Charleston, SC
Posts: 2,980
Total Cats: 14
Default Looking for opinions - T25/28 or T28 FM3

OK, I sent my FM3 T28 out for an inspection (rebuild) the other day. My T25/28 combo is burning a little oil and I plan on rebuilding it (just slapping in an oil seal) myself. The question is, which should I put in my car?

T28 pros:
won't worry about cracked manifold again (cast iron log vs SS tubular)
maybe 30 extra horsepower
will be able to more easily put store bought heatshield on

T28 cons:
will be expensive to rebuild (the blades on the compressor are eaten up)
won't spool fast like the T25 does
will have several issues with hoses/bolts that I don't yet have
will have to redo some of my IC piping
DP is only 2.25" and rusty as hell - may require a remake

T25 pros:
fast spool up
will be cheaper to rebuild
already have it tuned in

T25 cons:
manifold will break again
dp is still screwy (is not parallel with the ground due to it being cheap)
power dies at 6500 rpm
never really did fit in the engine bay
rmcelwee is offline   Reply With Quote
Old 06-24-2006, 06:04 AM   #2
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2005
Location: Charleston, SC
Posts: 2,980
Total Cats: 14
Default

I guess I should say that it is a lightweight street car (kind of) that sees an autocross now and then.
rmcelwee is offline   Reply With Quote
Old 06-24-2006, 06:37 PM   #3
Senior Member
iTrader: (1)
 
Join Date: Dec 2005
Location: irvine, ca
Posts: 729
Total Cats: 0
Default

the t28 from FM and the t25 have the same flange. why not mount that on the the cast manifold and see if the dp fits? the gt25r has the same turbine housing as the gt28r.
kung fu jesus is offline   Reply With Quote
Old 06-25-2006, 12:07 AM   #4
Senior Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Outside of the Loop-ATL
Posts: 754
Total Cats: 0
Default

Quote:
Originally Posted by kung fu jesus
the t28 from FM and the t25 have the same flange. why not mount that on the the cast manifold and see if the dp fits? the gt25r has the same turbine housing as the gt28r.

His T-25 is off the mitsu car so the manifold he has is setup for a DSM turbo were the Fm turbo is step up for a T2 turbo.
wildfire0310 is offline   Reply With Quote
Old 06-25-2006, 01:21 AM   #5
Senior Member
iTrader: (1)
 
Join Date: Dec 2005
Location: irvine, ca
Posts: 729
Total Cats: 0
Default

ah. that explains it.

if you have the fm3 manilfold you can use an external wastegate. that should help negate the lag of the t28. if the compressor wheel is all that needs replacing, i would do that.

i have and fm3 manifold, but i have the external WG blocked off and am using an interna WG. i may try to use the ext. wg at some point.
kung fu jesus is offline   Reply With Quote
Old 06-25-2006, 02:33 AM   #6
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2005
Location: Charleston, SC
Posts: 2,980
Total Cats: 14
Default

I might try to build my own DP with the flanges on the existing DP. That should be fun. I just need to find a source for piping. All I can find around here is really heavy big gauge pipe and not that thin light stuff that the FM manifold is made of. I'll try the external WG since it is different (a new experience) than what I am doing now.

BTW, the external WG ties into the dp at a 90 degree angle. Is that normal or should I try to bring it in at an angle? It seems like that would make for smoother exhaust flow.
rmcelwee is offline   Reply With Quote
Old 06-25-2006, 09:55 AM   #7
Senior Member
iTrader: (1)
 
Join Date: Dec 2005
Location: irvine, ca
Posts: 729
Total Cats: 0
Default

i don't know. i guess i'm thinking that it's like blowing across the top of a soda bottle. b efire i can go exWG, i need a 90* pipe for it to clear the turbo. whether i would plumb it back to the DP depends on how loud it would be and the danger facter of the fumes.
kung fu jesus is offline   Reply With Quote
Old 06-26-2006, 02:54 AM   #8
Newb
 
Join Date: Apr 2006
Posts: 8
Total Cats: 0
Default

you can get a 14B off a a 1st gen eclipse pretty cheap.
chiman72 is offline   Reply With Quote
Old 06-26-2006, 03:33 AM   #9
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2005
Location: Charleston, SC
Posts: 2,980
Total Cats: 14
Default

Quote:
Originally Posted by chiman72
you can get a 14B off a a 1st gen eclipse pretty cheap.
Not sure how big that is?

Been working on posting an ad for the car on ebay this morning. Have been thinking about moving on to another project. The car has not been burning oil since I worked on the manifold (not sure why) and all this swapping turbos, and working on the website has made me think that this project is about to wind down. I just GOT TO work on something and I think this one is about finished.
rmcelwee is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
300hp from a 1.6, your recipe Pepino DIY Turbo Discussion 61 02-02-2016 02:38 AM
The "other" spool question stefanst DIY Turbo Discussion 44 09-28-2015 08:16 PM
Headphones PaperMate Insert BS here 32 09-25-2015 09:22 AM
Twitchy car (tail happy problem) bigben Race Prep 16 09-11-2015 04:41 PM
WTB 1.8 manifold and turbo (preferred ball bearing) AnotherDamnMiata WTB 13 09-11-2015 11:56 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 07:19 AM.