single turbo on N/A...bad idea?

Hey guys, my N/A has sat in the shed for 2 yrs now and thinking about putting it back on the road.

I was wondering is it a bad idea to install a single turbo to a stock motor? Only something small. Looking for 6-8pound at the most or what ever would provide minor benifit, just for that tiny bit extra horses lol and not keen to wind it out for hard work, just cruiz.

The motor is brilliant, always serviced, never thrashed, i am 3rd owener with 134k purchased it years ago with 83k on on the clock.

I can get all the gear easy enough to do the conversion but keen to hear any pro and cons.

Thanks, Ian

 

Cheers man, So wastegate pressure, would there be any spool sound (if any lol) iv been N/A all my life and havent had huge experience with turbo.

 

Sounds like a decent vehicle, why stuff it up?
Trade up to a good Twin Turbo if you want a turbo Z32.

 

Send me a PM mate

 

Eric did a good writeup on it, not sure if it survived the "great cull". Standard TT auto bits onto a na motor with no coolers.

 

id hate to sell/trade in, but might be the better way to go.

Cheers guys

 

Don't sell up, I'd like to see a set of manual turbos on an NA motor with a cooler setup, run around 8psi. Think it'd be punchy as, should last nicely too with a set of TT injectors.

 

Are you guys all on happy pills today? this idea normally gets shot down straight away!
I'm planning similar soon for an experiment if you dont mind waiting a while for some good first hand experience. This guy http://twinturbo.net/net/directory.aspx?forum=general&user_id=59905 in the US has two very different NA-TT builds, if you sift through his posts you can find some info.

Absolute minimum, aside from turbos and manifolds etc. are 370cc injectors (they're on their limit at 10psi with high comp so bigger would be better) and a tune as both standard ECUs run too much advance/aren't mapped right for the behaviour of 10.5:1 with boost. Dropping to heat range 7 plugs is probably a good idea, that's what ConverTT V1.0 is using.

After the basics any cooling you can add to make sure engine and intake temps are steady and reasonable will make your build much more succesful. If E85 is convenient for you it might make an awesome build

 

Wouldn't it be cheaper buying a tt and making it high comp, rather than hunting down all the parts for the conversion.

 

Depends on the deals you get going down each path, there are enough TTs wrecking that with patience you should be able to an alright price on most of the bits. Adding boost to the high comp engine definitely isn't the cheap option when it comes to adding a bit of power and from what I've seen you seem to end up with about the same power as a TT with 12psi or so. It's not an objectively good idea but it not that terrible either, should yield a more efficient car depending on tune and makes the build more interesting

 

awegazm in WA has run two or three NA+TT motors. they go well tell they blow up.

 

Whats the difference in the block between the NA and tt, besides the obvious?

I know that NA sr20's have no oil squirters below the piston, so when turbo'd the pistons and rings cant be cooled sufficiently and burn out.
Extra fuel seems to help cool them.

Coming from someone that drives an NA+T on 10psi for a daily, who goes thru 3 engines a year... if i had to do it again id get a turbo long block and throw in some forged NA rods,pistons and such to bring it up to high comp.

 

in the block the differences are the pistons and compression ratios, the sump has the oil pipes oil hose pipes for the oil drain, and i think that the oil squirters are either different or not present at all.

 

also

it may depend on the block that Nissan used when building the engine, I have just been pulling an N/A block down and found oil squirters in it? confused the hell out of me, but the block did come from an Aus spec so, Who knows
Andy

 

Oil squirters are definitely present on the NA and (so i am led to believe) are actually better than the tt squirters (for forged builds) due to the angle in which they squirt - directly into the centre of the piston. As most forged pistons do not have this off centre hole, it is beneficial for cooling of the piston to use the NA squirters as they are able to cool the crown area more efficiently.

Taken from Z1:
1. The cylinder block castings and main caps are the same. They both have oil squirters that direct oil towards the underside of the piston, but they point at different angles. The oil squirters on the TT direct oil straight into an off center hole on the underside of the TT piston, which leads to a hollow area inside the top of the TT piston. The NA squirters direct the oil towards the middle of the underside of the piston, which has no passages inside.

 

Whats all this bollocks about high comp turbo engines.
Some guys speak of them akin to the holy grail............. Its a modification for modifications sake. Pure and simple
If upping the compression is so frikken wonderful then it would already be done from factory. So many snoozers seem to think there is so much powah to be had by upping CR's a few points...horseshit.

While there are extremely limited gains to be had, there are many valid and overriding reasons why its not everyday practice and one that being it slots the engine into a far narrower tuning zone when dealing with pump fuels and their inherent anti-knock variations.
Dont be seduced into thinking that the Nissan ECM is some kind of technological masterpiece either able to deal immediately with such chicanery. Its a very basic and simple item that is designed to do a particular job and wont sing God Save The Queen in 3 speeds if you ask it nicely..
It does the job it was given ok.

A comment above suggest that bigger injectors are a must due to a few points higher compression.... bollocks.
Desireable yes, essential? Not at all!
You dont need additional fuel just because of high CR. Stoich and best power fuel ratio is what it is and isnt influenced by CR.
Excessively rich mixtures on their own only go a certain way towards controlling the dreaded detonation issue which plagues high CR force-fed engines.
Go onto Youtube and look up Nelson Racing Engines and have a look at the data on some of their big HP engines.
These guys are pushing over 1500 FtLb touqe (2000+ Horseys) out of those animals they build at mid 12 afr's...Coincidently, thats the afr that results in highest Hp anyway.. Funny that

In fact adding extra fuel, along with the grossly retarded ignition settings required to control flame front propagation using pump fuels can easily result in melted valves, piston crowns and deadly pre-ignition due to skyrocketing EGt's yet, still not actually cause any detonation!
DONT confuse Pre-ignition with detonation either. Totally different animals altogether altho often considered the same issue.

This is where so many ordinary tuners go wrong. Just adding fuel and retard ignition for a "safe" tune. In fact its often less safe that a "good" fine tune!!!!!

You would use TT injectors AND a TT ECU purely to take out the tuning guesswork and then just pull ignition out of it until it stops rattling at the boost pressure you use.

Pointless modification imho and as mentioned above, best off to just chuck an old TT setup on it.

/rant
E

Of course, all this assumes pump petrol. Modify the setup for E85 and away you go with whatever tuneup you like.

Eric hase a reasonable handle on doing this conversion and didnt note any real world increases in powah over similarly boosted TT's.
Hes a reasonably smart fella and would push the barrow pretty hard to generate work for himself if he thought it would rfesult in real word powah gains.

Its a pointless exercise unless all you have is an NA engine to get your TT going again.

 

Tas great post and understand/agree with everything you've said.

However

I've also been thinking about this but haven't yet done any research, not so much from the point of view of increased (peak) power (which is all anyone who doesn't really understand much about tuning usually refers to lol), but more area under the torque curve, especially in the lower rpm range before boost kicks in. I would assume a higher compression engine will have more power below say 4500pm which would result in a much smoother more useable boost curve if tuned correctly.

For motorsport applications, I want smooth progressive torque lower in the rev range to pull the car out of corners while still maintaining the benefits of full boost power once the car unwinds down the straights. ie more torque low down before boost kicks in.

Your thoughts?

 

It just doesnt return the benefits against the drawbacks. This has been shown time and again.
There are a couple of guys on here who have actually done it, and an equal amount who reckon they are going to do it.
And the mythical benefits of extra torque and horsepower are simply not there.

Weighted against the drawbacks, none of which are insurmountable tho, its pretty much modification for modifications sake!!

Now, the addition of some hot fuel, or corn juice... well THAT is another story and youd prolly make some gains in the area your interested in!

E

 

I know pmack had a interesting engine built a while ago. High comp aftermarket pistons, 2560ks, cima heads and other toys. Not sure if he ever ran it... He had some clever ideas floating around in his head. Unsure of fuel and intercooler plans though.

I would only do a na-TT if I had the crap sitting around at home (as many of us do )