upgrade turbo

turbodig

turbodig

Active member
Re: upgrade turbo

Rookie said:
The GT35R is the better choice. The 25g is half the price and will make the same power. The 25g has a 12cm housing and that should be spoolable on the stock converter. The housing on the GT35R is probably bigger. That may mean bigger converter even though it is ball bearing.
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The fact that it has a larger exhaust housing is a *good* thing.

Never ceases to amaze me how people think they can put a giant compressor side on, with a puny exhaust side, and expect to make power. You're pushing more air into the motor, and it has to come out someplace. If you're trying to jam it though a small exhaust housing, you're losing a bunch of HP in pumping losses just to get the exhaust out. Not to mention, the additional heat and intake charge corruption, which leads to more deto.

The "normal" 20g upgrade turbo has a 14cm2 housing, and IMO, it's a bit undersized.

Turbo selection is a big deal, and if it isn't planned properly with corresponding improvements in fuel and overall tuning, you'll end up worse off than you were with the stock setup.
 
The Devils Own Chariot

The Devils Own Chariot

Active member
Re: upgrade turbo

I agree with you. In my case I think it will be fine. The turbo is rated for over 500hp. Most of the 20g turbos I see have 7cm and 8cm housings :dunno: Thats why its important to have a high flow exhaust. Stock trucks with cats cause the same effect with to much back pressure. The 17c turbo has an 8cm right? That turbo has been in 11's. Not being huffy just having a discussion.
 
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It's just a six

It's just a six

Super Member
Re: upgrade turbo

Rookie said:
Most of the 20g turbos I see have 7cm and 8cm housings :dunno:

Those are used on small 4 cylinder engines.

Thats why its important to have a high flow exhaust. Stock trucks with cats cause the same effect with to much back pressure. The 17c turbo has an 8cm right? That turbo has been in 11's.

It would run faster w/a different turbo & easyier to run that fast also.

Not being huffy just having a discussion.
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IMO:tup:
Here is a 20G for a little less.
http://cgi.ebay.com/ebaymotors/ws/e...0101613899&sspagename=STRK:MEWAX:IT&viewitem=
 
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It's just a six

It's just a six

Super Member
Re: upgrade turbo

Rookie said:
That also has a really small exhaust housing. I got my 25g for less than that. Its also a mitsubishi turbo. The only thing is its not a direct bolt on install like this 20g. The oil drain flange is larger and the DP bolts up but needs to be modified.
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After looking @ that Ebay turbo,it does not look like a 20G.

It does not have an "H" turbine wheel.??

To me it looks almost like a stock turbo.

If your downpipe bolts up to the 25G,what needs to be modified?

BTW,what size turbine housing does it have?
 
The Devils Own Chariot

The Devils Own Chariot

Active member
Re: upgrade turbo

It's just a six said:
After looking @ that Ebay turbo,it does not look like a 20G.

It does not have an "H" turbine wheel.??

To me it looks almost like a stock turbo.

If your downpipe bolts up to the 25G,what needs to be modified?

BTW,what size turbine housing does it have?
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I was just thinking the same thing about that ebay 20g. Looks 100% like a 17C.
Do you know where the downpipe attaches to that little flange by one bolt. It rubs on the frame in that area as it turns down. No big deal. Im thinking about going 3" anyways rather than making the 2.5" work.

Compressor Wheel
55.5 / 77.9 mm (Inducer / Exducer ) = 66.7 trim

Turbine Wheel
55.8 / 66.3 mm ( Exducer / Inducer ) = 61 trim
 
Nitrous

Nitrous

New member
Re: upgrade turbo

The guys on ebay (Turbochargers.com) are actually the guys I'm buying the turbo from and they're about 20 minutes from the house. They don't recommend the 14cm housing because the spool time is slower and they say the smaller 8cm housing with the gt35r will make me happier. I can buy the Bad Dog with 14cm housing turbo for a little over $700.00 from them if I wait on a large order from them and pick it up in person. They've made over 600 HP with the setup they're building me. I'm not looking for an all out race truck, just a play toy. I'm going to be able to keep the stock A/C also so no issues there and they machine the compressor housing to accept the stock inlet elbow. I was torn on which way to go but these guys are local and if I'm not happy it will take the turbo back to them. If I'm happy I'll have my original turbo built as a spare. BTW, 3 dyno pulls at their shop for $35.00 isn't too shabby either. :tup: BTW, I have a 3000 stall converter so that'll help also...............they'll start the build tomorrow so I'll inquire about the exhaust side one more time.
 
The Devils Own Chariot

The Devils Own Chariot

Active member
Re: upgrade turbo

C what did I say about the smaller exhaust housing. Dig is right about his views on the larger housing. I would not shy away from a larger housing turbo with your stall.
 
It's just a six

It's just a six

Super Member
Re: upgrade turbo

If you have a 3000 stall,a 14 cm housing will spool up fast plus give you better top end charge.:2cents:

With my custom turbo http://www.syty.net/forums/showthread.php?t=53545 I am using the stock 2100 rpm converter & it just has enough stall to get to full boost from a dig,it is a bit laggy,but I can deal w/it.

I am thinking if & when I change the torque converter it will run 11's. I am thinking about 2800 stall will do it.:tup:
 
The Devils Own Chariot

The Devils Own Chariot

Active member
Re: upgrade turbo

It's just a six said:
If you have a 3000 stall,a 14 cm housing will spool up fast plus give you better top end charge.:2cents:

With my custom turbo http://www.syty.net/forums/showthread.php?t=53545 I am using the stock 2100 rpm converter & it just has enough stall to get to full boost from a dig,it is a bit laggy,but I can deal w/it.

I am thinking if & when I change the torque converter it will run 11's. I am thinking about 2800 stall will do it.:tup:
Click to expand...

Just a question. Why would that custom turbo you have be any more laggy than the stock one. Your still using the stock exhaust turbine right?
 
It's just a six

It's just a six

Super Member
Re: upgrade turbo

Rookie said:
Just a question. Why would that custom turbo you have be any more laggy than the stock one. Your still using the stock exhaust turbine right?
Click to expand...


I am using a 12 cm turbine housing.

The 60-1 wheel is bigger/heavier than a 20G compressor wheel ,therefore a bit slower also,until it's starts grabbing boost,then it's really quick on the boost.

So I call my turbo a TDO6H-60-1G turbo w/a 12 cm housing.;)
 
Osmosis

Osmosis

New member
Re: upgrade turbo

I ended up getting the RPM BB 60-1 turbo and I had some lag. I had to change my converter to a 2800. IT's still a little laggy compared to the stock turbo and stock TCC when driving at part throttle. IF I stand on the throttle, it's in the power band.

Initally, I had a 57mm hybrid turbo and I could not tell much difference from the stock turbo. I ended up getting an RPM stage 3 60-1 turbo. AFter all is said and done, I regret not spending the extra cash and getting the gt35R:roll:
 
Nitrous

Nitrous

New member
Re: upgrade turbo

:rotf:The turbo has been a tough decision so I have them doing a little research now for the best combo. All the turbo's posted here seem like positive upgrades I just don't want to get too far away from stock but get the best bang for the buck. The more you guys post the more I get to thinking on which direction to go.........................:rotf::rant::rotf::roll:
 
turbodig

turbodig

Active member
Re: upgrade turbo

I've had 3 different converters with my 20g/14cm2-

Stock: A bit laggy, but workable if you tune for it.
TCI 2600 : Very little lag. Hit 20 psi just after the 1-2 shift.
TCS 9/11 2800: Lag? What Lag? Could hit 20 psi+ before the 1-2, with little effort.

This turbo went 11.8s with a really good tune. Traction was more of an issue than anything.

I've seen lots of the Hybrids come in go in the 15 years I've been dealing with these.
DSM turbo vendors like to push small exhaust housings with big compressors. This seems to works with their motors and combos, probably because of the manual trans issue.

The Syty peeps that have had them, one of the following usually occurs:

1) Too big of a wheel on too small of a turbine shaft, wears out quick and compressor blades contact the housing.

2) Too much exhaust backpressure kills top end. You get 20 psi lightning quick, but your 20 psi makes less power than somebody else's 15. Got a Typhoon here that had what looks to be a 70-ish compressor side with the 8cm back end. Spooled great, but never ran more than mid 13s. I get stockers faster than that quite often.

3) Screwey wastegate configuration causes weird boost control; motor goes *poof*.

.... or, a combination of the above.


You also have to consider the type of driving you'll do, and the type of gas you're gonna burn. If you don't have race gas in the tank, or an alky system of some type, forget about running much over 16 psi. High boost on stock motors with unassisted regular pump gas is a recipe for a dead motor.

If you're not going to run more boost than that, there's not much point in going with a larger turbo. The bigger turbos need to produce more boost in order to run efficiently. Running a huge turbo on a stock motor with a stock converter, at lower boost levels *will* make you slower than you were with the stock turbo.

I can't count the number of Sys/Tys that I've come across that had some massively large turbo with no converter, with the owner scratching their head wondering why it was running slower than before. Even the best tune in a screwed up configuration will only go so far.

Personally, I wouldn't even *think* about changing the turbo until I was well into to 12s. And then, you really have to decide your intent- is this gonna be a 10-second killer, or something more sedate?
At that point, you buy the proper turbo, converter and injectors for your goals. And, you will have a fair amount of tuning to do, or pay to have done.

At the end of the day, you have to ask yourself *why* you want the turbo- Is your intent to really go faster, or is it just so that you can say you have turbo (x)? There are many, many ways to get to a specific performance goal, and a turbo is often not the best way to go about it, bang for the buck wise.
 
The Devils Own Chariot

The Devils Own Chariot

Active member
Re: upgrade turbo

I think a 12cm exhaust housing is plenty big for a stockish truck. Going external wastegate on the crossover tube will give you great boost contorl (if you can tollerate the noise). My goal is not going to be 10's. 12 flat or maybe really high 11's is my goal. Your talking to much money for me when you try and break into the 10s. 11s on the street is plenty fast. Pluss I dont want a caged up truck. A nasty street machine is all I want. Supras run the 25g or also known as the T67. They end up with plenty of top end as we all know.
 
Nitrous

Nitrous

New member
Re: upgrade turbo

Great reply Turbodig! I agree with you and my main reason for a new turbo is because mines shot. I'd like to see low 12's or high 11's but don't really need go overboard on this truck, that's what my 97 is for. If I'm going to buy a new turbo I'd at least like to upgrade and eventually build a forged bottom end when it's time. I could probably get by fine with a TDO6H with no problem. Money isn't my issue, I just want something reliable and that will work great down the road with a rebuild.
 
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