hi everyone i have a greddy turbo kit the size of the turbo is a 18g i wanna know what size is a 18g like t3/t4 or something like that i wanna add a bigger turbo and keep the same manifold anyone who can help me thanks

 

also whats the max psi the 18g can handle or hp?

 

Its between the GT2860RS and 3071. The 18G should make between 380 and 430hp.

 

This is totally wrong man. The 18g is pushing it past 325whp. Just look at the compressor map.

To Op: It uses a T3 inlet flange and a T25 outlet I believe.

 

thank you

 

The 18G is a 42lbs/min turbocharger, slightly smaller than a 50trim T3/T04E turbo.

But it will not reach those levels that ScorpionT stated for several reasons;

1) Those power levels are at over 2 pressure ratios. At 2.0PR the 18G is only 640cfm. A honda's map sensors need to be changed to a 3 bar to even approach that level

2) Restrictive downipe and downpipe elbow. This is one key problem. This dp is very restrictive and limits power output considerably. This must be custom changed.

3) Wastegate spring. The wastegate and flapper door as it comes in the kit is limited to about 14psi, and even then w/ a boost controller, it will drop to about 10psi due to the flapper door only being about 31mm (smaller than a TiAL wastegate opening).

to make over 380-430 crank hp, look to over 20psi to do it.

This is similar to the 18G, since this is a Garrett/Mitsubishi Hybrid turbo using a T25 inlet and outlet from garrett and a mitsubishi compressor cover and cartridge.

 

this kit is going on a built ls bottem and a port and polish ls head i was hoping to make 400hp max i have a 3bar map sensor would 15 psi get me there

 

Definatly going to need to ditch the elbow and downpipe if you wanna get anywhere past 300. And its gonna take closer to 20psi like shodan said.

 

thanks i might just sell the kit and buy a different setup bigger turbo and ram horn manifold i think 20 psi is pushing the stock sleeves

 

Thats a good idea. The kit is really meant to be a nice easy bolt in, nice daily driver kit retaining all the factory stuff, not to make serious power.

 

yeah its on my integra now stock ls it is my dd but i bought the built bottem end and low on money because im also converting my front to 01 and painting the car to so its gonna be close because i need to have 500 to get it tuned that will come before the paint

 

That's all the advice to give, sir. No other way around this. The Greddy is for a bolt on 200-330whp max setup. You'll need to prioritize if you want power or style. With a limited budget, you won't have both unless you plan FAR ahead.

 

That 18g on an ls can make 350 whp. I made 318whp and 306 ft lbs of torque at 20lbs on my ls. My turbo is just a little bigger though, TD06-20g. Not that much bigger. 3inch downpipe to 3 inch complete exhaust. External wastegate.

 

My car right now makes 250whp/240trq at 12 lbs with the 18g, but theres nothing from the original kit left except the turbo and manifold.

 

380-430hp WILL be enough for 325whp, big chief. I didnt say whp, so that means crank horsepower.

The GT28RS is 36 lb/min, 3071 is 44 lb/min, and the 18G is 40 lb/min.



Shodan, you should know I wont assume a completely stock setup. The turbo does in fact flow enough for those power levels, so its possible with supporting mods. Wayyyyy back in the day, a buddy of mine had an 18G and made over 300whp with room to move, so 400 crank hp isnt out of the question.

 

I understand where you're coming from, but you and I are different from this OP, in which we can take the time, effort, and fabrication to make it create this amount of power. But you and I both know that is a lot of work that the OP has no idea on what to do to begin. You're also looking at the compressor wheel CFM flow capabilities and not exhaust side of things. Flapper, wastegate, turbine wheel, the list goes on. The issue isn't is this type of hp from this turbo "out of the question", but rather "is it practical for his needs?" We can all agree the answer is no based upon his time, budget, and knowledge.

 

Its not "out of the question" but its definatly not the best choice considering other alternatives. 400 "crank" Will be pushing the turbo way out of its efficiency range.