I picked up a local gtm de kit for a good price, I don't plan on building my engine and I currently have 112k miles clocked in. How high are the risks from just running on wastegate springs alone without a boost controller? Has anyone blown a motor from just that? I tried going through the search. No luck as of yet finding a story.

I'm going to do a leakdown/compression test in a few weeks, nothings wrong with the car at all I just want to be sure.

If everything doesn't pan out I'm just going to sell it.

 

It depends on your tune, and the springs. If the springs are set to 20psi, then you are f*cked.
It also depends on the turbos in there.
If you are not running a tune, DO NOT GET INTO BOOST.

PS I see you are on youtube, lul.

 

I have Osiris so im sure I can work with that plus any other things I need to get like injectors and fp, and no i meant like really low boost lol


yep, that video would be nothing without the viral spread that started on this site.

 

Wastegate springs are fine, but I would make sure you know for sure what PSI they are.

Every motor is different, especially with those kinda miles, but doing everything correctly will help offset the chances of something going wrong.

 

I see. I never knew they varied like that, I always assumed that they all came holding a set rate without a controller.

 

Yep. I forget what model Tial's GTM uses, but figure out the model of the wastegate and then look what color the spring is. Tial has the pressures listed on their website.

 

New Oil Pump, Rings, Bearings, Seals. By the time you replace those items I would say just save up and do a basic build. 100K motors have life limited components and boosting them will just push them past what many would call a caution area. I was on just wg on a jet 530 kit and had bearing failure and rod failure.

 

Pretty much what I needed to hear. I'm surprised no one else has posted any known failures of someone running on just minimum boost.

 

Well that has more to do with the motor condition.
See at 90k+ the bearings start to loose their outer softer layers, and become more and more rough the deeper you go. This is normal, but the added power increases the force on those components of the rotating assembly. So, the increased ''clamping" forces seen on the bearings combined with more friction can spin bearings.
I got a block from a fellow my350z member with 97k miles on it. When I tore it down the bearing wear was all normal; even and clean without inconsistencies, BUT they were well worn in. The bearings were past the soft outer layer and were beginning to get into the harder metal down below. The motor probably would have been able to last with a good oil, but I would not have trusted it under boost (aside from the fact that a piston smacked a valve lol).
Edit (ninja dual post)
They do come with a set rate and hold it without a controller, but there are mannnny mannny different springs out there.
If you do the supporting mods and get a tune I think you should be ok, but like I said earlier I wouldn't really trust it based off what I saw in my now being built block. Although do remember every case is different, maybe my block's previous owner was especially hard on his car, or neglected to change oil or used a cheaper less refined oil etc. If your motor has been perfectly maintained, and you never beat on the car maybe you have less wear etc.
Just understand you are at a higher risk of motor failure. I think if you kept up on your oil changes, and use a good synthetic you should be ok, at least for a little while.

 

Good stuff, looks like I'm not out of the woods yet then.

Come to think of it I just realized that, I knew that before I just never thought of it now probably because I just assumed all kits had pretty basic wg's.



For what its worth, I literally drive like a grandma on the street.

 

Alrighty well, I decided to make use of goin deep's short list on engine building. Hopefully this will make a reliable 320-350 whp without any worries.

In case you forgot it was:

Connecting rods |X|
Pistons
ARP Main studs/Head studs
Rod+Main, Bearings
Overhaul Gasket Kit
Rear Main Oil Seal
NGK one step colder plugs
Boost gauge
Oil Press gauge
EGT Gauge
AFR gauge
Clutch Upgraded
And the following depending on boost levels:
AAM Fuel Return System
Bigger fuel injectors

I just ordered Eagle rods as of this morning, I'm hoping to complete this list by summer/fall 2013.

If anyone else has extra advice on other new components I could possibly use since that list is pretty old, I'm all ears.

 

2013?

 

Yep. It might take a while..

..for me at least.

 

Well on the bright side, that will definitely give you time to research what you're doing.

 

Agreed. Maybe this will be done sooner considering the fact that I'll be ordering pistons within the next week.

 

Noob question....when ur messing around with a boost controller i.e turning ur boost up, does this make it so the wastegate needs more pressure to open...therefore giving you more boost?

 

Somewhat.. depends on style of wastegate - internal vs external. On an internal, you are 'tricking' the wastegate into thinking boost is lower by altering/limiting the vacuum line going to it, therefore it will not open. On an external with dual ports, you are applying boost to the top of valve/spring thus trying to keep it closed and building more boost.

 

There is no 'safe' boost with 0 miles or 100k miles. Don't go F/I unless you're financially prepared to rebuild/replace your engine at any time, and can deal with the car being down during that time.

 

also, i think someone beat around the bush with this answer so i'll state it more clear:

wastegate spring verses boost controller makes no difference on safety. 6psi on spring and 6psi on boost controller is still 6psi of boost. ya, there are differences but it's not a "blown" engine on one verses the other.

so no, it's not unsafe as long as you know what your wastegate spring pressure is.

 

Just got my rods in today, so I'm like 1% there.

I may have failed to mention this already, but I'm only rebuilding the motor for strong reliability. Granted I could probably make 500whp etc on my future setup if I really wanted to, I'm really only looking for 330-400 whp on a decently built motor. ridiculous no?

And yes, I'm aware of the cheaper f/i alternatives it takes to reach that goal.