thoughts about 18G
 

I have a Mitsu 18G in my 99 GST, and the spool time is somewhere between forever and 5000 rpms. When I get to full boost (+/- 17 psi right now) she runs like mad, but getting there is somewhat more turbo lag than I expected...of course I still need to free up the exhaust a little more...going full 3" soon with a ported o2 housing as well.

Here's my prob...I have a friend willing to trade a ported/clipped 16G for the 18G. I know it'll spool faster, but is the difference worth it? I'm not looking to be an all out race car, just quick for the street (let's say trap about 105-110 mph range in the 1/4). In your (smarter) opinion, which turbo would you go with and why?

Thanks in advance for the help,

Re: thoughts about 18G
 

Your car has serious issues if its taking until 5k rpm to fully spool. You should be hitting full boost no later than 3500 rpm's. Free up that exhaust and check for boost leaks then make your decision. Both are great turbos, but the 16G is more efficient and will spool slightly quicker assuming your 18G is also clipped (15* seems to be the norm for those). I had a ported/clipped Big 16G and loved it, I regreted ever getting rid of it. Is your 18G ported/clipped as far as you know?

Re: thoughts about 18G
 

not as far as I know...second hand. I know my exhaust is hurting me, but wasn't sure if the turbo was helping it's cause...I'll get to like 12 lbs at 3500, then it goes all the way up to 17 psi just before 5k...like someone kicked the door open.

No leaks...I've replaced every hose, every gasket, every everything I can touch or see...OCD kicked in when I bought the car.

Re: thoughts about 18G
 

What are the specs on the turbo exactly? What size is the housing, if its the 8cm that could be why its so laggy. I think most 18Gs come with a TD06 cover, TD05 turbine wheel, and 8cm housing.

18G=Spool of a 20G or bigger with the power and potential of a big 16G.

You could swap the housing for a 7cm to make it a little less laggy. Or just buy a different turbo all together and sell the 18G to some dumbfuck on Tooners.

Re: thoughts about 18G
 

Most 18G's that I've seen have the TDO5H cover and a 7cm turbine housing. Basically the same as a Big 16G with different wheels.

Re: thoughts about 18G
 

Yeah maybe thats just the Greddy one I am thinking of. Either way its not a great turbo in todays standards.

Re: thoughts about 18G
 

I guess an 11.320 at 123.94mph with the FP 18G must be a pretty shitty result then.
http://linux.forcedperformance.net/m...Code=DSM-Turbo
http://www.dsmtimes.org/times.php?He...llTurbo&Page=1

I guess we all need GT42Rs to make any headway on the track. ;)

Re: thoughts about 18G
 

I doubt even an 8cm housing could make that happen; I had a Super20G on my old 1G, and it spooled 20psi by about 3800 at the latest, and that is with a 10cm housing. What is your base timing set to?

I once spoke with someone who was trying to fight knock & run high boost on pump gas w/ a scm61 (which should spool on a stock motor by around 4500, right?). Anyways, he had his base timing set to -5 degrees or more and it didn't spool until like 5500 or 6000 rpms.

Re: thoughts about 18G
 

Yeah and Curt Brown went 10.920@124.90 on a big 16. So whats your point? I never said it couldn't make power. I just said thats it spools like a 20G and has the power potential of a big 16G.

Re: thoughts about 18G
 

Don't we need a car that we can race to go to the track first?

Re: thoughts about 18G
 

My point is that way too many times in threads like this where a traditional turbo is being rippped on result in people thinking a moster turbo is needed to run decent times.

Re: thoughts about 18G
 

Huh?

Re: thoughts about 18G
 

The 18G is inefficient that is all they are saying. They also said its not worth going with an 18G when a 16G or 20G are better alternatives.

Where did anyone mention that a huge turbo is needed to run fast times?

You also mentioned the gt42... that is what LSE is using on Johns car so that is why Swanny responded that way.

Re: thoughts about 18G
 

I wouldn't call an 18g a traditional turbo. It has been around for a long time and never became popular for a reason. A small 20g smokes it in all aspects.

Re: thoughts about 18G
 

i think swanny was just making a dick comment because jakey's car isn't running.

i find that VERY ironic.

oooooo drama

Re: thoughts about 18G
 

No one mentioned here specifically here that a huge turbo is needed but when one spends as much time as I do browsing forums, it is all too evident that too many people think a monster is turbo is needed to run fast times. When I made the comment about the GT42R LaCroix's car didn't even come to mind, I thought of it because that is what Shep & AMS run and I had noticed that when browsing for 18G times on dsmtimes.org.

Re: thoughts about 18G
 

My car runs, it just don't move. :D

Re: thoughts about 18G
 

That is what I meant by traditional. My apologies for not being clear with my connotation.

Re: thoughts about 18G
 

Just giving ya shit :).

I wasn't being defensive, and for the record, john is running the cheaper non ball bearing gt42 :).

Re: thoughts about 18G
 

It would run down a hill damm fine!
Wait, no it wouldn't, its actually light right now :(.

An onto the turbo thing: An evo 16g is very comparible to the flow numbers of a 18g, with much less "lag" which we have all learned is from the devil. IMHO the 18g isn't a very good setup if someone were to buy new, there are much better turbo's on the market, including stuff from MHI themselves.