Just wonder if it's safe to run synthetic oil on a turbocharged car?
Does it effect lag? Thanks in advance.

 

No it doesn't affect your turbo lag at all. It's actually recommended to run synthetic for the same reasons it is in a Naturally Aspirated engine.

 

Ah considering synthetic oil is vastly superior to normal oil, I would say yes.

 

I wouldn't consider myself an engine guru, but I can tell you that synthetic oil is FAR BETTER for your engine and extremely hot turbochargers.

The reason people associate synthetic oils with lag is because with synthetic you can get away with a lighter viscosity(ie 5W vs 10W), which WILL help the turbo spool faster due to decreased friction losses from the viscous drag in the center section.

Basically, a thinner oil reduces lag, but with turbos' harsh breakdown of oil, you really should have the synthetic for it's increased resistance to thermal breakdown.

 

Not to step on your toes but one should run synthetic for protection, not to really spool up the turbo faster. In reality, the turbine, compressor sizes and design play the biggest part in the turbo's characteractics.

 

I figured that was implied with the "you really should have the synthetic for it's increased resistance to thermal breakdown.", although that was not the real point of this thread.

Yes, turbo lag can be caused be several factors including improperly matched compressor/turbine wheel sizes which cause slip, however the weight oil you use makes a considerable difference on lag.

If I had a turbo, I'd run 0-WT synthetic and use oil analysis to judge how frequent it needed changed.

 

If I had a turbo or supercharger, I would not use anything but synthetic oil.

Speaking of weight, I would try a 10w-30 to give enough film strengh for good protection and reduce the turbo lag.

As for brands of oil, Amsoil or Redline would be my choice.

Redline is a group 5 (highest rating) oil, ester based that was originally designed for racing engines. http://www.redlineoil.com/products.htm

Amsoil is a group 4, PAO based (what the old Mobil 1 used to be) that is an extended drain oil for normally aspirated engines. It is also a good choice for turboes since it has a high flash point. http://www.amsoil.com/products/atm.html

 

Okay I'll bite. Where can I read that that an engine's oil weight(within reason ie.. 20-50 weight) can make a bigger difference (or even I significant affect on the turbo's ability to spool?

 

Wait a minute! I didn't say it's a "bigger" difference than slip, just a SIGNIFICANT difference.

Just off the top of my head:
http://www.redlineoil.com/frames/engoil.htm

"Red Line 5W30: Provides the quickest starts and fastest oil pressure rise. Will reduce turbo lag and provides more power and best economy in an engine in good condition."

http://www.redlineoil.com/frames/engoilti.htm

"Less turbo lag will be noticed with the 5W30. If ambient temperatures will regularly climb above 100°F, then the 10W40 would provide an additional safety margin."

I know it's just a slogan for selling you oil, but I'll see if I can dig up more info tonight. I think there is an article in one of my magazines.

I'll keep you posted.

 

Alex, yeah that's a little thin. I mean it probably reduces lag the same amount it improves fuel mileage. Which is what? 3-5%? Hardly significent IMHO. Let me know what you find though

 

I still haven't found it.

However, it does say "Less turbo lag will be noticed", so it can't be negligible, if it's noticeable. Anyways, it seems that Redline is the biggest reference to reducing viscous drag, so it may just be Redlines' propaganda for selling their product.

However, I did find "The reduction in viscous drag and friction of the ball bearing center section can reduce turbo lag by 500-700 rpm in itself." according to http://www.se-r.net/about/200sx/scc/feb99/turbo.html. I'm not about to say the viscous drag difference from a 10W to a 5W or even 0W is the main difference, but clearly viscous drag is one of two frictions that allow you to spool 500-700rpms(I've also seen 400-800rpms) sooner. Is 100rpms significant? How about 200rpms? Also, not just benefiting lag, but I'd say at 80,000 to 100,000+rpms compressor speed, viscous drag is going to serious affect turbo efficiency, so 5% could easily be 15hp, maybe more on a 300+hp vehicle.

I'll keep looking.

 

Ball bearing center sections do help significantly. Price one out sometime and see how much that few hundred rpm cost you.

 

A lot.

 

I'd pay it in a heartbeat.

The two major advantages are far superior thrust bearing life and reduced viscous drag. The reduced viscous drag is why they get top dollar.

Glad you FINALLY came around Kev!

 

Okay Alex, buy a turbo. est $700ish. Then buy a BB turbo. Probably $2000ish. Still ready to buy one?

 

Yep, sure am.

Except it's only $1500ish withOUT even shopping around.

GT25 - 440 HP .82 A/R (Maximum HP 500) $2595 Australian dollars.

http://www.turbofast.com.au/sales.html


Still worth every penny for the reliability, efficiency, AND 400-800rpm faster spool up.

 

So it's $1500 shipped to your door from Australia(ie.. shipping/customs duty/customs clearance etc?) Cool. What size is the GT-440? Because a small T3 might have a max power rating of like 300+hp, but it's not very efficent at that power level(ie.. over 15 psi or so).

 

Like I said, that's not shopping around. So, I'd expect it to be even cheaper from someone around here. Are you looking for one? I can look harder if you're interested.

I'll never see 400+ hp and 15+psi, so a T3/T4 hybrid or similar will be fine.

As far as efficiency goes, these are low to mid 80's(percent), which BLOWS away non-Ball Bearing center section turbos(low to mid 70's, I think).

 

So you're gonna go turbo?! Cool! When?

 

Just pipe dreams my friend, pipe dreams.

However, if I have this car for 2 more years and there is a TRUE bolt on(not customize like Kev has) kit, I will. I'm "only" interested in ~300whp/300wtq since it's a FWD, so it's not going to be some monster like Nigels or Kevs or even some of the SC guys.

The damn EVO VIII and upcoming STI are really tempting me though, so I doubt I'll last 2 more years.

BTW, I do work for the company that owns Garrett, but I doubt I could get a discount myself, let alone others.

 

I found a shop here in AZ that sell the GT35R (630bhp) for $1465.

http://www.i-m-racing.com/l3rturbo.html

 

To quote Ghostbusters "That's a big twinkie!"

 

Ok...so that's a "little" overkill.


Here's a GT30 for $1375:
http://www.i-m-racing.com/l3rturbo.html

 

A DISCOUNT...are you absolutely insane? They dont even pass out raises...ROFL...

 

Actually, I know a guy that bought a couple....he paid MORE than I can find them for on the internet.

You didn't get a raise?

 

You know it's hard to say "I can justify or I would spend xxx more for 400 rpm of spooling" when your not really serious about buying a system.

 

Honestly, Jeff I know for a fact that's what I would choose IF that day comes. However, there is a new dual charger system coming out, so by then, that may be the better option for me.

The efficiency and faster spool up are a bonus. The 4-times reduction in thrust bearing failure is the real justification for me to spend twice as much now vs. replacing/rebuilding later.

Some people are willing to pay less up front, but they will end up paying more later. I would rather spend it upfront PLUS get the faster spool up and higher efficiency. Too me that just makes sense.

 

Honestly, Jeff I know for a fact that's what I would choose IF that day comes. However, there is a new dual charger system coming out, so by then, that may be the better option for me.

The efficiency and faster spool up(up to 800rpms!) are a BONUS. The 4-times reduction in thrust bearing failure is the EASY justification for me to spend twice as much now vs. replacing/rebuilding later.

Some people are willing to pay less up front, but they will end up paying more later. I would rather spend it upfront PLUS get the faster spool up and higher efficiency.

 

Okay. But when I had the T3, I had plenty of boost down low for me. My turbo only cost $300 to completely rebuild also. If you maintain your turbo, it should last well over 50,000 miles(as many non-ball bearing turbo have/will). IMHO, I can't justify a BB unit unless I was going to a BIG turbo that needed help spooling. Or if I was building a mega-system like Kev is doing. But in reality, boosting a na V6 motor(that already has good compression)should give you good lowend anyway. And that high compression fact should limit the boost anyway. So for me, that eliminates most of the bigger laggy turbos from the get go.

 

I've been using mobil 1 10w-30 and 5w-30 in my '95 Talon Turbo since it was new.

The turbo is in perfect condition with 130k on it.

I used synthetic with the turbo because I figured the better thermal properities would mean less chance of the oil drian tube getting coked up.

The t25 in my talon is a garret, it's a sleeve bearing type. I never once used a turbo timer either.

I've also been using a JoeP MBC on this since about 90k and I'm running 16 PSi right now, so I'm spinnning it faster than it was ever meant to be. 130k on it, and no hint of play in the shaft. The compressor wheel looks like it did the day I bought the car.

 

Good points! I guess there is no single answer and that's why it's so difficult for me to pick which one. Not even getting into trim and A/R. Hehe.

What rpm did/does your T3 hit full boost? What psi is full boost? Also, why did you have to rebuild your turbo and at how many miles?

 

Yeah, many ways to skin a cat in forced induction.

I had full or close to full boost by 3000-32000 rpm or so. It's hard to tell because I ran it on the stock fuel system. I only floored it a few times. Most of the time, I gingerly got into it.

I rebuilt the turbo after I took everything off. It was an old one and the compressor side seal was letting oil into the charge side.

 

That's impressive to me!

No turbo timer...do you ALWAYS allow it to cool down before you turn off the engine?

Did you ever notice a difference with the 5W vs. 10W?

 

A lot of what I'm "designing"(in my head) will depend on how Kevs' setup turns out on the dyno.

He is way waaay past where I want to end up, but his turbo vs. Nigels will show some interesting differences, I suspect.

Now if he'll actually get the damn thing running, I can get started.

 

I never once even cooled it down. It's a wet turbo (water jacketed with coolant flowing through it)

Most of the info I've read on it and experience I've seen guys have with a wet turbo is that cool down just isn't necessry. Now a dry turbo is a different story, you should have a cool down on those.

I never noticed any spooling difference when I changed viscosity. I run 5w-30 in winter and 10w-30 in summer.

When I first got the car back in '95, I was a bit worried thinking I would always have less reliability with it than a N/A car. I was wrong. I did basic maintenance and refrained from 7k launches and bouncing off thge rev limiter on every trip, the car's been great to me. Believe me, I have my fun with the car, I never did beat a car as much as I did to this, and the thing runs like new still.

I had read back in '95 that most turbos don't live past 70k miles, but I've seen some surveys over at the dsm forum http://www.dsmtalk.com with a lot of guys going upwards of 150k on a turbo before it decided to take a crap on them, even then it was seal relalted (started to leak oil). A lot of guys concluded that turbo timers were bling_bling (on a wet turbo). A lot of the high-mile guys never cooled down or used a turbo timer.

2k3 max 6 speed, hlsd, ???
95 Talon 13.38@101

 

Very very impressive. I've been contemplating picking up a '92 GSX or AWD Talon for my daily driver/track car, so I try to keep up with what's new.

 

They're great cars, a lotta bang for the buck. Just be careful what you pick up because these cars tend to get beat on. 92 would be a great year, one of the more reliable engine years. With AWD, once you get good at launching at the track, 1.6 second 60' times are the norm

The 2nd gen (95+) have a rep for thrust bearing failure (crank walk), but I think it's blown out of proportion. Some 1st gens complain about crankwalk, so who knows...I hear the supra guys complaining about it on their "bullet proof" I6... The one common theme ya see with these are usually heavy clutches. Mine of course never got it, at 130k, if I do get it, I wouldn't care because the engine doesn't owe me a dime.

I just got my max and can't let go of the talon. It's just to easy to mod and make fast. It's the kind of car you wear, not drive, it handles so well and is so responsive to everything.

Good luck!

-Steve
03 max 6 speed hlsd
95 Talon TSi.