whoisEion

I got a Greddy 18g Kit on my Integra, it works and nothing's wrong with it. This is only for future references especially when the turbo seals fail or whatever can go wrong happens. I am wondering what parts of it can be replaced and or upgraded? I been googling around and seeing people using 20G turbine wheels and compressor housings but I want to know more and with detail.

TheShodan

iTrader: (14)

The Greddy 18G is a Mitsu/Garrett hybrid. Using the Turbine wheel/ turbine housing of a GT2860RS equivalent and the compressor wheel of the mitsubishi 18G (with a TD05H Compressor cover. When you want it "rebuilt" internally, you want mitsubishi parts for most of the turbo.

whoisEion

Wait.. I never knew that the turbo was a hybrid. I guess people really do learn something new every day. Now since I don't know much about the science behind turbos. I'm assuming that it would increase the spool and output of the turbo correct? Would it last long too?

TheShodan

iTrader: (14)

Not necessarily. "spool" is simply the moment of inertia. "Long lasting" has nothing to do with what you're asking. It has to do with how well it was put together as a manufactured part and how well it was maintained.

93h2beg

so whats the best way to increase boost with these Greddy kits? replace the turbo with a gt2860rs?

TheShodan

iTrader: (14)

You can effectively get 350whp provided that the wastegate actuator is upgraded using the GT2860RS unit, or convert the turbo to work with an external wastegate, change the elbow on the downpipe elbow by using the downpipe flange from the GT28R, so you can get a 3" downpipe.

whoisEion

Okay, but wouldn't upgrading the turbine housing and turbine wheel result in better performance? More top end if I'm guessing correctly?

TheShodan

iTrader: (14)

Top end power, yes. To about 44lbs/min (a bit less than a 50 trim T3/T04E Garrett or equivalent). The turbine housing will only extract about 20-30whp more at best. A GT28R turbine housing machined to match that exhaust wheel (I don't remember the turbine wheel diamater off the top of my head) would need to be performed. 350whp on the curent turbine housing will do fine with that exhaust wheel. For the expense of that turbine housing upgrade + the actuator + the compressor wheel + machining the wheel to fit, you'd better be getting that turbo for free and willing to spend no less than about $400-$600 in costs.

whoisEion

The gt28rs or the 18g?

TheShodan

iTrader: (14)

Modifying your 18G.. Will cost more than you think. Especially since you have to use a mixture of part companies to do it.

eg6islife

I have an 18g, that came with a gt28 actuator right now I put down 300whp at 21psi on my fully built b16, without vtec. Also i was running on pro series stage one cams.(to much back pressure) i still have the stock downpipe and will be upgrading the down pipe to 3inch. theres someone on the forum that has a built b16 with ram horn with t3 mani and external wastegate sitting around 400whp. I will be pushing the 18g to see what i get and later upgrading at the end of summer.

but sheldon is right if you want more power buy a new turbo and mani/downpipe. but again if your like me i got my kit for free with the actuator so i thought this was relevant. im hoping to get a new mani as well. we'll see. 350 on my DD would be good enough. id like 400 on paper but jusst gotta wait.

wantboost

iTrader: (2)

The 18g isn't t3 flanged, so that wouldn't work.. and I know who you're talking about but there's no way to make 400 to the wheels on a stock 18g, the compressor barely flows enough to make 400 AT THE CRANK... someone has a cheating dyno, end of story.

eg6islife

Correct, switching it out for the gt 5 bolt flange(t3) yes you can. so you can run a t3 mani its been done. as for the graph here you go.

https://honda-tech.com/forums/forced-induction-16/greddy-18g-fully-built-b16-2751485/

wantboost

iTrader: (2)

Yes you can swap housings, but it only helps a minor amount, changing to a larger 20g comp, wheel would be much more helpful in power production.

Seen that thread, he has sold that setup. And the graph only shows 350, and there's no way an 18g makes 350 at 16psi, I've discussed that in detail with TheShodan when I saw his fs thread...

eg6islife

Opps wrong thread this is what one I'm talking about. The only thing that he changed from what I read was the turbine side not the compressor side? I know there is a correction on this one as well. But all in all that's some good power for an 18g.
https://honda-tech.com/forums/forced-induction-16/tuned-dynod-fully-built-motor-18g-turbo-2816770/

TheShodan

iTrader: (14)

And you'll also see my comments on that as well. He had a stuck wastegate (he says boost controller, it was that the gate wasn't strong enough.

Again. this has been done, albeit with some work. please search the 3 threads for the 18G in existence on the FI forum

Downpipe modification
https://honda-tech.com/forums/forced-induction-16/end-all-greddy-18g-downpipe-dilemma-thread-2906474/

26psi limitation on 18G
https://honda-tech.com/forums/showth...3072161&page=3

A clean modification of this turbo
https://honda-tech.com/forums/showthread.php?t=2751485

A 4th thread. One that ended relatively quickly with asking the same questions.
https://honda-tech.com/forums/showth...1#post48412982

wantboost

iTrader: (2)

Now this has me curious about the 18g

eg6islife

That's what I thought about the boost at 16psi cuz I'm at 21 right now.

msgs350

You can get this rebuilt if the seals leak by a turbo re builder. However, if it cracks (which mine did), finding a direct part from Greddy is almost impossible since this kit has been discontinued.

Almighty-Si

I wouldn't worry too much about upgrading your turbo, rather it's the manifold, downpipe and wastegate that's the real problem.

I too am running the GReddy 18G turbo, and the stock kit (minus the 2.5 inch downpipe from the elbow back, test pipe and exhaust) put down 193whp on my stock everything B16 at I'm going to say 7psi (the internal gate would never hold pressure steady) since that's where it sat the most.

After getting frustrated with the boost pressure floating around I decided to get a new manifold (ramhorn) and run an external wastegate. Went back to the same dyno, little warmer weather, same stock everything B16 and 2.5 inch downpipe off the turbocharger now, test pipe and exhaust...on wastegate spring pressure (5psi) the car put down 223whp. I also did a 9psi pull and netted 272whp but stopped there because injector duty cycle was in the high 90% range (440cc). I just recently finished a bunch of upgrades (headwork, cams, TB, rods, pistons) and will be cranking this turbo until it screams bloody murder and I think I will come close to 400whp with it.

I guess what I am trying to say with all this though is, now, that I think about it and if I could go back and do it all again I probably wouldn't. All the time and money I just spent on supporting mods just to try and 400whp out of this turbo, I could have bought a slightly larger turbo and made the same or more on the stock block and probably would have saved a good amount of money.

So I say, drive your car...enjoy it...save your money, and when things go south with the turbo...take the money you saved and buy another set-up.

wantboost

iTrader: (2)

Gimme the turbo :p

msgs350

Agree with this completely! I'm now stuck because my Turbo housing is cracked and unable to get a direct replacement from Greddy because this kit has been discontinued. SUCKS!

wantboost

iTrader: (2)

Define cracked

Show us a picture or two, small cracks in turbine housings and cast manifolds are common and normally have no ill effect on usage and performance.

msgs350

I will do that when i get to the shop my car is at (next week). They were originally going to replace the seals because i was getting oil in my exhaust but when it was sent out to a turbo re-builder, it was determined it couldn't be saved due to the cracks.

wantboost

iTrader: (2)

Yea because if they are tiny heat cracks, no biggie
The larger ones can be welded and ground down but normally all you would see is tiny stress cracks