alex91n/a

iTrader: (2)

another quick question. how low of boost can u run on a gt35r? can you run like 9 or 10? i assume you can. but im just wondering

ifryrice

You can run as low as your wastegate spring is set for, or as much as your wastegate can flow if it's undersized.

K-Tune

iTrader: (26)

don't use carbon apex seals in boosted engines.

KhanArtisT

iTrader: (2)

LOL, and out of all the factors that can lead to a broken apex seal you somehow landed on compression? At 15 psi?

Don't blame the engine for your incompetence or mistakes and preach about it like someone else can learn something from it. Saying that 5psi is "pushing it" on a 9.7:1 engine is absurd and complete BS. I've driven my car for 10,000 miles+ at 5-6psi on a stock TII ECU with no tuning. I drive the **** out of the car too.

RacerXtreme7

iTrader: (2)

Carbon seals in a street engine? Pointless, pointless in anything other than a RACE engine that sees HIGH RPM (READ: 8500+ RPM) . They wear out extremely FAST, are light weight and don't seal for **** till they get high in RPM, and they do NOT like being boosted (they break easily with little detonation or extreme heat {READ: boosted applications}). They were specifically designed for race engines for several reasons, 1 being rotor housing friendly (this is why they wear out so quick), race engines are broken down frequently so replacing seals is no big deal, and re-using EXPENSIVE rotor housings was a must. 2 for extended high RPM operation (the reason they are so light weight, and because they are so light weight with weak spring tension not too mention 1 piece design they don't seal for **** until they are spinning 8500+ RPM).

Boosted high compression rotaries? Bad idea. YES they are used in some boosted race engines, yes some guys can get away with it on the street. But here's how they get away with it for extended periods of time, they have bullet proof fuel systems and high resolution aftermarket EMS systems and GREAT TUNING among MANY other tricks here and there such as correctly temperature ranged plugs. Yes there's a few shade tree mechanics in here that spout off about "I have XXXX miles on mine and no problems"..blah blah blah. I know Cocaine addicts that snort 8 ball after 8 ball for years and their not dead yet, so that must mean snorting cocaine night after night must be OK for your body right? Yes you can run high comp rotors in a boosted engine, but the margin of error is tini tiny. Even if you got tuning down and a bullet proof fuel system and safe guards such as knock detecting timing retard, all it'll take is ONE BAD TANK OF GAS or a really hot dry day (or even worse BOTH) that you didn't quite get those cell ranges tuned for those temperatures yet and your rebuilding again. At least with turbo rotors, the compression ranges allows a little room for error. A stock turbo engine with a stock turbo at reasonable boost can ping audibly loud for several hundred to several thousands of events and still survive. On a high compression turbo engine once you've heard it, it's probably too late. So why risk it? You want better off boost response then use a bigger exhaust. Fab a 3.5" system with several resonators and large mid and rear mufflers for none-ear bleeding decibel levels. You now have an extremely responsive turbo and a happy engine.

BTW, the above rant is aimed mainly at shade tree mechanics looking to run mid to high levels of boost (14~20+ psi) on larger then stock turbos (T04E to Gt35r / 60-1 sizes) or high boost (14+ psi) on small to mid sized turbos (stock to T3/T4's, To4b's, To4E's, Stock turbo hybrids etc.). High comp engines and low boost don't need all the safe guards and aftermarket gizmetry to work ok. A good example again of doing things right would be Arrons 6 port high comp GT40 engine were every aspect was well thought out and bullet proof.

Just my $0.02

~Mike..............

ifryrice

Very good points, the tuning and properly building for it can't be stressed enough. If people would do the research and know what they're getting into instead of just trying to make X horsepower with whatever they've got laying around there'd be a lot less dead engines out there. But hell, a lot of that applies even with low compression too. People have to think of those thing and make safeguards for it. AI is definitely the secret to removing almost all of those problems though. AI makes the reliability of high compression turbo cars damn near silly. People tend to ignore/overlook it, but just injecting water alone on your base tune goes a hell of a long way into protecting against those 'hot days' or 'bad gas' days. And since you're not tuned to make use of that added protection, you usually don't even run into a problem if your AI clogs/fails.

Still, I'd strongly discourage anybody who hasn't done the research/know what effects temperature rise play and the effect of moving that from the turbo compressor to the engine have from using high compression. Less room for error, but if you're prepared it can be managed pretty well.

NoPistons!

iTrader: (3)

Reading is always good and i read project tina in entirety. Multiple times, just so i could figure out stuff, not replicate your setup. Some people fail to understand that because it's "the almost complete guide to turbocharging the na13b". That's not bad on your part, just the people without logic.


Turbo n/a IS a way to save money IF you dont want a TII of questionable condition. Picking and choosing EVERY part and knowing it's condition is cheaper than buying some bullshit that breaks on you the first time you hit boost b/c some packing peanuts fell into one of the exhaust ports/intake.

All in how you think about it.

JoeyFC

im going to run after market low comp rotors.

K!NCH

iTrader: (2)

Where in PA are you from? I'm from Pittsburgh.

Aaron Cake

iTrader: (1)

Those are interesting statements to make. I agree without a doubt that it is not the easiest, but I would like you to qualify saying that my setup was not thermally efficient, responsive or reliable because the fact is that it certainly was. I made more power for lower boost then a low compression 4 port with the same amount of fuel, so that is more thermally efficient. It was more response by far then a low compression 4 port block to the point where it was difficult to stay out of boost just cruising on the highway in 5th gear. As for reliability, I had no problems with the original setup save for splitting my rubber oil return line twice and that was my fault for making a stupid design decision.

I'm glad that my write up scares people! Most people should not be doing a turbo-NA project anyway. If they do choose to run boost on the NA engine, they should stick with a 6 port TII setup.

It is also important to note that my writeup was compiled 10 years ago and is the "Almost Complete Guide To...blah blah...".

I must be doing something right though, because I have never blown an engine. Not a 6 port turbo, not a 4 port turbo.

Buy Jspecs from reputable dealers and you don't have to worry about their condition.

In the same sense, it makes sense to worn people who are completely unfamiliar with what needs to be done that perhaps the path they are starting down is the wrong way to go. Just saying "Yeah, go ahead! It's easy!" is another blown engine and some wasted money. There are loads of threads here where people have done a turbo-NA or 6 port TII setup only to post back a few weeks later that their engine is blown.

Exactly. It is utterly pointless to go through all the work required for a turbo NA setup to only run an ancient stock turbo that has been considered a piece of junk for a lot of years. The only thing the stock turbo has going for it is that it bolts right up, and is cheap. But to bring the boost into the "fun" level brings the turbo out of it's efficiency range and turns it into a heat pump.

GT3076R with a 1.06 turbine. 300HP and better response then the stock turbo.

13 PSI without the boost controller enabled and last dyno was 392 RWHP. 14 PSI with the controller on low (420 to the wheels) and 16 PSI with the controller on high (right around 500 HP at the wheels).

These are key questions. A decent sized intercooler and proper engine management are the most important. The effect of a big intercooler cannot be underestimated. On the dyno, at 13 PSI, my intake temps as measured in my plenum were just above ambient! Cooling like that is important, especially when using an inefficient turbo like the stock one. A larger turbo will run far cooler and make more power then a smaller one for the same boost level (generally speaking). Thus, one should upsize the turbo a bit when doing a high compression turbo NA setup.

Any aftermarket turbo kit for the TII will fit the NA engine if you use the TII upper and lower intake. This involves porting the TII lower to fit the NA block, which I believe has already been discussed in this thread.

Running carbon apex seals, on a street engine, under boost? No wonder they broke. Carbon seals are for high RPM NA operation only.

A friend of mine had (until water froze and cracked the block this winter) a bone stock GSL-SE 6 port block running a China T4B making about 320HP for the past two years at 15 PSI or so. No issues. My original setup use my 6 port S4 NA block with 250,000K on the clock and ran a HT-18 at 8-12 PSI. No issues. Of course, I didn't put carbon apex seals into either engine.

Or any sort of street car or any rotary that has to idle or operate at low RPMs...These are race seals only for NA use.

Bingo. And that I freely admit it is only one way of doing things, plus the write up is 10 years old. I'm going to be updating the NA-turbo guide with more options (like using TII intakes) soon.

Basically. But regarding a TII in questionable condition, just be a bit proactive in how you shop and make sure you are buying good parts.

From where? There are only a handful of people machining rotors into low compression, and none of them are cheap. Just use the TII rotors if you want low compression.

JoeyFC

racing beat makes nice rotors and yes the are a bit much for them.

rotordad

Well as far as low comp rotor there's no need to spend a pile of money on the Racing Beat assembly, I agree to just use the Turbo II rotors. Personally I use the 9.4:1 rotors in both my Supercharged car & my Turbocharged car. As said before keep your tune right & you should have no problems.