Problems With Using a T25 On the 420a

[TotalEclipse420]

whats up everybody...this is my first post here on dsmtuners...

anyways to the point...i recently aquired a T25 from a friend (traded some old stereo stuff i had laying around for it) and from what ive read most people dont recomend it because of a lack of parts...but since "T25" is too short to search for i cant find a lot of info on that topic...can anybody tell me why...also...since the wastegate on this turbo is internal...to make it easier...instead of doing the wastegate mod with a spring...could i just weld the flap closed and use an external wastegate?

thanks in advanced

by the way i have a 97 eclipse rs

 

[sheldon]

you could but gains are minimal to do an external gate on a t25 with low boost. (i'm assuming you're running low boost b/c you have a 420a...if wrong correct me) just port the dump for flapper so you dont boost creep and bee done with it...

 

[GSTeclipse]

you could but gains are minimal to do an external gate on a t25 with low boost. (i'm assuming you're running low boost b/c you have a 420a...if wrong correct me) just port the dump for flapper so you dont boost creep and bee done with it...

Boost creep should not happen on a t25 !
Now running low boost what do you mean 6-9psi come on bump it up to 12psi they run 6-9psi on a bolt on Hahn or Star kit for the 420's and that using Super 16g turbos that flow over 505cfm's .......

 

[95TalonOwner]

Yes you can weld it shut and get an external wastegate. That would be waaaay more reliable then trying to mess around with the internal wastegate and spring mod crap. What you could do is remove the flapper completely, then there would be more room for the exhaust to flow out since you would be using an external wastegate anyway.

To sheldon, I'm sure he's just asking since the 420A can handle on 8 psi max with stock internals and only around 4 psi with no intercooler and the stock t25 wastegate spring is set too high for a 420A.

 

[TotalEclipse420]

just to clarify...yes im still running stock internals and i dont plan on pushing more than 5 psi...i may get a EBC if i feel the need to turn it up to 8 very occasionally...but this is my daily driver...at least for another year or so...so i need to be easy on the car because i cant afford to go out and rebuild at the drop of a hat if it blows...at this point in time i just want a little more power...going to be on the safe side with every aspect of this project if i can pull all the resources together to do it

hate to start a compleatly different subject but as far as an exhaust manifold goes...instead of forking out 75+ bucks for a flange plus pipe elbows and what have you...could i use the flange from my stock header....like...cut everything off it and weld on the pipes as desired?...not sure where my stock header is so i cant look at it at the moment but i cant see why this wouldnt work if i find it

 

[dr1665]

I was about to dock points for the 12psi remark, since anything above 7psi intercooled on stock internaled 420As is cruising for a bruising, but that's typically on a HRC 10cm^2 16G and not a puny T25.

Otherwise, I've nothing to add in terms of converting a T25 to externally gated other than it seems like a waste of time to me. So much work for a turbo best used as a base for a lamp.

 

[GSTeclipse]

I was about to dock points for the 12psi remark, since anything above 7psi intercooled on stock internaled 420As is cruising for a bruising, but that's typically on a HRC 10cm^2 16G and not a puny T25.

Otherwise, I've nothing to add in terms of converting a T25 to externally gated other than it seems like a waste of time to me. So much work for a turbo best used as a base for a lamp.

I was assuming he was going to use some kind of front mount or even a side mount thats why I said 12psi

I put a Hahn Stage 2 kit on a Stock 420a Eclipse that had 100k on it and we pushed 9psi -10psi using a Boost controller over the wastegate spring and made sure Fuel pressure was set right and also used a PLX M-300 Wideband set up and got the AFR to around 11.3 using a AFC 2 and he has been on it for well over a year now and that kit came with a Super 16g

 

[DSMcrazy3]

I was assuming he was going to use some kind of front mount or even a side mount thats why I said 12psi

Even with a front mount, 12 psi is just too much to be considered safe on stock 420a. I'm with Driggs, anything over 7 and you're asking for it.

Yes you can weld it shut and get an external wastegate. That would be waaaay more reliable then trying to mess around with the internal wastegate and spring mod crap.

First of all, the spring mod isn't crap. It's a great way to lower boost on a wastegate set for higher than desired levels, instead of buying a new wastegate.

What you could do is remove the flapper completely, then there would be more room for the exhaust to flow out since you would be using an external wastegate anyway

How exactly do you plan on building boost like this? That flapper door being shut is what allows boost to be built. If you were to just have a hole there with no door, the majority of the air would bypass the turbine and cause a horrible spool time, or no spool up at all. If you decide to go external, that original hole needs to be filled/covered.

 

[TotalEclipse420]

Otherwise, I've nothing to add in terms of converting a T25 to externally gated other than it seems like a waste of time to me. So much work for a turbo best used as a base for a lamp.

I understand this is a small turbo and I'm not going to see a lot of boost from it, but it serves my purpose, and i didn't really pay anything for it.

Secondly, I'm planning on running a FMIC of some sort, because they just look plain cool , and they do a better job than an SMIC. I know you lose boost with any IC, but is a 550x230x65 (ebay turbo xs) going to kill way too much boost? I know the size seems a little overkill for only 5-8 pounds of boost, but like i said, i may pull the motor for a rebuild on down the road and swap out for a bigger turbo since i didn't pay for this one, not to mention, big FMICs on DSMs just look sexy .

Lastly, now that I've looked at pricing on external waste gates, i think I'm just going to do the waste gate mod and be done with it.

 

[TotalEclipse420]

Well, I bought a spring, and the way the rod comming of the waste gate is, a washer wont stay on straight. Basically the waste gate mod is going to be semi-troublesome. I think going with an external gate would be safer, not to mention easier.

What do you guys think about this one?

Also, if i were to do this, where on my setup would i mount it?

 

[DSMcrazy3]

Well, I bought a spring, and the way the rod comming of the waste gate is, a washer wont stay on straight. Basically the waste gate mod is going to be semi-troublesome. I think going with an external gate would be safer, not to mention easier.

What do you guys think about this one?

Also, if i were to do this, where on my setup would i mount it?

The bolded statement says it all. No offense to you but you really need to do some more research before you attempt this, or go buying gobs of parts.

That said, the external wastegate is mouted on the exhaust manifold. You'll need the appropriate flange welded to the manifold, which the wastegate will bolt to. From there you will run a tube from the wastegate to your downpipe.

As for that particular wastegate..While you're doing more research, be saving your money. Go with a Tial.

 

[TotalEclipse420]

Yeah I know I'm no turbo expert, and I don't claim to be, but I thought there may be something special to do since my turbo has an internal wastegate. And I don't plan on actually starting the install until December.

 

[VelocitàPaola]

http://www.dsmtuners.com/forums/showthread.php?t=181134

BAM! Everything you want to know, and then some...

Read it.
Learn it.
Live it.

Anything else we can help you with today?

 

[TotalEclipse420]

I've seen that thread. It was my basis for my parts list. I've almost finished it I think. Once its done for sure I'll post it for review

 

[cs82685]

As for that particular wastegate..While you're doing more research, be saving your money. Go with a Tial.

Listen to the wiseman, the wastegate is not where you wanna skimp on quality especially stock bottom end & injectors. Tial all the way if your not gonna mod the wg actuator

As for the manifold, are you planning on fabbing up your own? Just wondering cause I don't think I've ever seen a T25 on a 420a, but if I remember right someone crudely used the stock exhaust manifold to bolt up a 14b too. If you are gonna do all your own fabrication then you can do this fairly cheap, as you saw from gsgoinfast's write-up.

To me hahn says 8-9 psi max and even with a T25 I would stick with that since it's gonna have to spin quicker than a 16g or something comparable to build an equivalent amount of boost. I don't know if the extra revolutions would really create that much more heat, but I wouldn't trust going above that. Although if you've done your research, people have run on 5psi and blown their engine rather quickly while others have run 10psi or so and been fine for 1yr+ It all depends on the condition of your engine and your driving tendencies

 

[TotalEclipse420]

I feel pretty good about my engine's condition, I can floor it, and at wot have no smoke coming from my exhaust. The normal burnt a/f gas is hardly even noticeable at wot too. The only engine problems I've really had is some bad smoking and water from the exaust, but i had the head gasket, water pump, timing belt, all the drive belts, and my valve seals replaced, and it disapeared. I know this doesn't ensure safe boosting, but it makes me feel more comfortable about it.

As far as boost lbs, I think 5 will be my max, period.