4age setup for earliest full boost?

[ATAl]

I'm trying to get an idea of what can be done (except swapping turbo) to make full boost earlier for my engine, it's being fully rebuilt so making some kind of hybrid engine is fine.

Would a smallport or bigport head result in earlier boost?

Would cleaning up the ports and adding larger exhaust valves (plus enlarging exhaust port to fit) on either head help?

What cams are best for early boost - redtop / bluetop / something else?

Quad throttles do anything?

Basically if you have any ways of making boost come on earlier post them!

[Monsterbishi]

Fit a reducer in the vac hose going to the wastegate actuator, in my old GVR4, the factory one was about 1.25mm ID, allows for the air to get through, just slightly delayed to cause a faster spoolup by keeping the wg flapper closed slightly longer.

[vvega]

I'm trying to get an idea of what can be done (except swapping turbo) to make full boost earlier for my engine, it's being fully rebuilt so making some kind of hybrid engine is fine.

Would a smallport or bigport head result in earlier boost?

Would cleaning up the ports and adding larger exhaust valves (plus enlarging exhaust port to fit) on either head help?

What cams are best for early boost - redtop / bluetop / something else?

Quad throttles do anything?

Basically if you have any ways of making boost come on earlier post them!

eazy get some antilag or nos

v

[evil_si]

or try telling us some info on what u actually running,
engine, and whats been done'
turbo specs
intercooler size
computer
fuelling

[ATAl]

4agze 8.9:1 compression

stock cams
stock head
tubular turbo manifold
some kind of t3 hybrid turbo
stock injectors
upgraded fuel pump
stock computer
vr4? intercooler - might be something else seems to big for vr4

This was all on the old engine, the turbo made 5psi from 2000rpm then at 4800 went straight to 11psi (wastegate set to this) which is held as far as I've ever revved the engine.
I'd like to get the turbo to make 11psi by 4000, thus giving me a useful powerband from 4-8k rpm.

Because of part of the block breaking off I have to build a new engine so I'm gathering pieces and trying to figure out what can be changed to improve turbo response.

As I'll be changing the ecu antilag may be an option, but I'd be too worried about long term damage to make much use of it.

Nitrous is just too much hassle.

[ATAl]

Another question: The turbo has plain bearings right now, can these be changed to ball bearings? Any rough idea of the cost?

[B-style]

hey dude, nah you can't change to ball bearings might aswell just get another turbo (that is already ball bearing)! if you want better response get a standard t3 turbo!

[86 Power]

Why do you care about early full boost. You will find that if the max potential of the turbo is reached too early in the rev range it will be causing a heap of heat later ion the rev range.

I would say your options are smaller intercooler, ignition timing, higher compression, larger capacity (7age) ballbearing turbo, nos, antilag, smaller turbo, perhaps try playing with the manifold design also, to make the most of what you have...

Heaps of weays to play with turbo setups eh.

[Rollux]

Roller bearing turbo and electronic boost controller. I'd go with something like a GT28RS and Profec B personally. Good for around 340hp efficiently. Wll give good spool up time and good top end for a 1600.

Expensive tho

[anthonym]

It appears to me that you're hoping to bolt together a hotch potch of cheap parts and acheive and ideal boost response. If so you are not likely to succeed.

You can't expect to bolt up a turbo that fell off the back of a Skyline or whatever and achieve an ideal boost response, you also won't get very far with the stock ECU.

If you are prepared to explore these avenues, the main thing to consider when choosing the turbo is the size of the turbine and the a/r ratio of the housing. To achieve maximum response these need to be as small as possible while still flowing enough exhaust gas at peak power, whatever you might desire that to be (probably a good place to start). Once you've got the turbine sorted, match it with a compressor with sufficent flow to achieve your power goal.

A programmable ECU is the other essential component needed to optimise boost response, preferably with a boost control function. You also want the compression ratio as high as possible without detonation on the fuel you intend to run. Pretty much everything else is relatively insignificant as long as the basics are covered (good intercooler etc etc.).

[matt dunn]

On a similar topic,

Does an External wastegate help boost response over an electronically controlled internal?

Matt

[EVLGTZ]

On a similar topic,

Does an External wastegate help boost response over an electronically controlled internal?

Matt

Response? I'm not so sure. Maybe between gear changes but I cant pick much of a difference in the initial spool.

One thing tho is that on full boost it seems to pull a bit better and just keeps wanting to go. This may be due to mine be vented externally and not back into the exhaust and therefore less back pressure???

I've tried manually and electronically controlled internals and both manual and electronic boost control with the external and by far the best on my setup seems to be electronic boost control with the external.

[anthonym]

On a similar topic,

Does an External wastegate help boost response over an electronically controlled internal?

Matt

Using a relatively large external wastegate with an optimised exhaust flow path can be very useful in that it can allow use of a smaller a/r ratio turbine housing. Such system permits increased exhaust flow at peak power over what would be possible with a small internal wastegate, which effectively increases the operating range of the turbine.

[ATAl]

Taking the raising compression option, how much boost is safely possible on 98 octane on engine with 8.9:1 pistons with a 0.8 mm trd headgasket? (That makes about 9.3:1???)

This is with programmable ecu and decent tune, and an fairly cool intake charge from efficient turbo and intercooler.

[EVLGTZ]

Well all depends of tuning but cant see why you couldn't get away with around 1 bar on that setup. All you would really need with an 'efficent' turbo.

If I were you I'd be looking at what you can do with that existing turbo of yours. Sounds like it's not matched as well as it could be.

[ATAl]

Yeah the turbo could definitly be a better size, but it came with the car, it's in good condition and has steel blades, and I don't want to go thru the hassle of trying to find another turbo in decent condition, new ones are too expensive and I have had way to many bad experiences with second hand stuff.

Basically I'm thinking of slightly raising the compression, cleaning the head up to flow a bit better and finding a ball bearing core for the turbo and getting it rebuilt (I know this is probably going to cost as much as a second hand turbo, but I'll come out with a turbo I know is as good as new). This combined with a new ecu should do the trick.

The other option is find a smaller ball bearing t3 (skyline?) second hand and get it rebuilt, this will probably cost less but result in less top end, and possibly result in ceramic blades going out the exhaust when boost wound up, as it will be.

Does anyone know how much power a stock skyline rb20 turbo is good for? (Without to much heat or self destruction)

[EVLGTZ]

Sounds like a shit load of work to do just to avoid changing turbos....

[Rollux]

RB powered skylines all use a ceramic bladed T28. 14psi is max boost you can wind in "safely" to avoid the wheel falling off. This is subject to how often you bounce on the limiter, tho!
Run out of efficiency at about 10-12psi tho.

[ATAl]

It's not really that much work as the engine is in the process of being rebuilt anyway, the head will be cleaned up, and compression raised regardless of turbo choice.

So the only choice needed to be made is second hand turbo + rebuild or current turbo + bb core + rebuild.

Also I could probably swap / trade in the current core as it is fairly new and has 360 degree thrust bearings. So there isn't going to be that much of a price difference.

[vvega]

ok so lets got with this path
when do you want boost ??
how much power you looking to get
where do you want the meat of the power

just a few answers and well se what comes up


v