I have already talked with a few people about this in detail

i blew a turbo seal and have to get the turbo(s) re-sealed and whatnot--i may go ahead and go up a size in wheel to a 20g..my take on this--the turbo would not require as much speed to produce the same boost--this would take some of the stress off of the turbo...
if i port and polish turbo--this may reduce some of the increased lag that i would experience with the larger wheel

i do not plan to make much more power than i do now--so the only reason for doing this wheel chnage would be to reduce stress on the turbo and increase its life

any comments..please!?

TODD

 

Todd, the Compression/Leakdown checkout out OK?

 

the 18g is a hd05 turbo, the 20g is a hd06. are you sure its as simple as swapping out the center? by this i mean do you know someone that has done this before? i know its possible, but i believe it takes a wheel made to spec for it to fit.

also the 20g is made for high boost, it might not be very efficient at low boost. what are your plans for what you will be running it at?

 

i do know that a company does that.... its either mtm turbos or mjm turbos something along those lines... They put a 20g compressor in a 18g spot after boring it out a little. As for efficiency i dont know... but you could do a search for the company i mentioned.

 

https://my350z.com/forum/showpost.ph...6&postcount=10

 

i see, and what is the price for the wheel upgrade? it should be no more than 1k a turbo right?

 

I'd vote yes for 20G.. gives you room to grow if you ever want more and if they are able to handle higher boost than the 18Gs, even better. If you're going to spend money to get the 18Gs rebuilt, you might as well go for 20Gs once they are out. Not sure how much spoolup would suffer but you could obviously get your current whp at lower psi as well so that's something I would definitely consider.

 

Please don't flame me as this is only a question. Why is everybody going higher and higher in hp when they can't even put the power to the wheels with 400whp? I don't understand this. Again, I'm not talking down to you, I am just asking a question but I can't see what good all this power is if your wheels just spin. If you raced somebody who had 400whp on a Z they may beat you because they have more traction. This would be the same for times at the track. So is everybody going for more hp just for showing off rights? Has anybody installed traction bars? Making all this power is useless after a point. It's like buying a powerful gun but you can't aim the thing.

 

Go for it You always need more boost

Az

 

I mentioned to Todd over the phone, that if his goal is to run 600whp and near 20psi or more boost, the 20G is the way to go. The turbo will last longer, and wont have to work as hard to pump the air.

But most of us settling into the 15-17psi range, in which case, the 20G will do nothing but increase lag slightly, but the 18G's are perfectly happy in the 15-18psi range with our engines.

 

The point is that once you hook you are gone. FYI there are SEVERAL boost controllers and aftermarket traction control devices that will limit the boost based on gear. So you will hook in first and second and the controller will gradually add boost as you go...

 

i'm leaning away from rebuilding with bigger wheels..but i am doing this:

"The super duty thrust kit removes the brass thrust bearing, replaces it with a steel
one, we then have to relive the cartrdige inside to install a much larger inboard
thrust collar and outboard thrust collar. This increases the thrust area by almost
33% so it makes the turbo MUCH tighter and MUCH more durable."

if you guys have questions about turbo rebuilds:
www.deadboltspeed.com

 

Here is another site for turbo repairs and upgrades

http://www.turbochargers.com

 

Realizing your turbo seal was gone ... did you do a compression/leak down test anyhow?

 

Trust me....DO NOT send it there unless you want it to smoke

 

What causes you to blow a turbo seal? What does it cost to rebuild a turbo?

In am in the process of building my short block and will have a similar set up as Todd. I would like to avoid what happend to him if possible. My greddy kit has about 10 minutes of use......I had engine damage on the dyno. Is there anyway for me to avoid what happend to Todd?

 

Good to know, I just came across them looking for options on the 300ZX TT.

 

do not be like todd...todd is not what you want to be like

no, really, my advice: when u rebuild, break in at no more than 11 psi of boost..with the normal motor oil...

switch to synthetic before high boost tuning...those turbos get hot and the lower grade oil can really do some coking at those speeds and temps (per conversation i had with sharif earlier today)

also, what type of engine damage did your car suffer? in my case, i had head damage and had shards of metal in the plenum!...chances are- metal shards went through my turbos as well, maybe some particles wedged in there and caused the seals to prematurely breakdown

i'm rebuilding them stronger than ever, contact jerry at deadboltspeed.com for a quote on a rebuild, you might consider having them inspect the turbos for any internal problems, and if they rebuild, have them do the upgrade to the super duty thrust kit- will increase strength and durability to an already strong turbo!

TODD

 

I don't know exactly happened to my motor. My shop was thinking something with the valves or valve springs due to my rev limiter being increased to 7100rpms. I was there when they were trying to figure out what was wrong with the car and I did not see any metal shards. They tried to turn the motor by the crank and it would not move so Kyle thinks it might be a bent rod. My motor is in route to SGP and I will know more when they tear it down.

As far as the break in, I plan on city driving the car for as many days as it takes me to hit 1000 miles. Since I am going to take some time off from work, I think I can do this in 2 or 3 days. I don't plan on going into boost during this time. After the 1000 miles, I will have the oil changed and dyno tuned.

 

Well up top highway at about 50mph this is where there will be a big diffrence between 400hp and 600hp.