boost on a R34

[gts4-skyline]

What sort of maximum boost would you reccomend running on a R34 Gtt. Just basic mods (exhaust, and a k&N panel filter) with a electronic boost guage. Keeping the standard turbo and intercooler.

Cheers

Glenn

[dojobi]

I think HPI blew their turbo at 0.7 or 0.8 bar. That was on the track though, so it would have been held at that for a while. I run my R33 turbo at 14psi, but it's only ever at that for a small amount of time, so it's pretty safe. I can guarantee you it'd blow on the track. What kind of application will you be using it for (ie street, track, drags etc)?

[adam 32]

12psi

[gts4-skyline]

It would mainly be used for the street, maybe a few trips down the strip. If I was to go out on the circuit what would you reccomend, keep it standard or maybe upto 10psi?

Cheers

Glenn

[dojobi]

Personally I'd keep it at around 9 or 10psi for the track, as I feel HPI were pretty unlucky. For the street around 12psi as adam said.

[Sydneykid]

There are two problems with the standard turbo, both centred around the ceramic exhaust turbine.

Firstly, being ceramic the turbine is sweated/bonded onto the common shaft and therefore it does not like too much resistance ie; the exhaust is pushing the turbine while the compressor is trying to move air into the engine. Too much resistance (boost) and the turbine and the shaft part company.

The second problem is one of heat, the ceramic turbine will only handle a certain amount of heat, coupled with this resistance. The heat builds up over several minutes of very hard driving (say on a circuit) and the turbine shatters or parts company with the shaft. Leaning out the engine to achieve more horsepower also increases the temperature of the exhaust.

So to answer your question, our experience has been that 0.8 bar (12 lbs) is OK for a road car as long as it is only in short bursts so that the heat does not build up. If you do any circuit work or long distance high speed stuff, then 0.7 bar (10 lbs) may well be the safe max.

With a really good intercooler, pipework and Power FC tuning we have achieved 0.8 bar (12 lbs) on a 220 RWKW road car reliably. But 5 hard laps on the circuit and the smoke escaped.

Sorry that this is a complex answer to your questions but it is a complex scenario.

[gts4-skyline]

Not a problem Sydneykid, an explanaition is always better than a straight answer. Just out of curosity, what do they run standard, I havn't hooked up my boost guage yet.

Cheers

Glenn

[NismoR34]

According to specs standard boost is .55 bar which = 7.9 Psi.