R34 Gtr Build

[r33_racer]

It does look that way now that you mention it!

John sure has some serious skills and clever ideas.

[BOBBYr34]

For a moment there I thought the ribbed piece of billet stainless was an expansion joint, but after watching the vid a few times I heard him say slip joint. Since its a slip fit it will take up any movement without cracking. Clever design!

I especially like how he has gotten the wastegate pipe to seal to the slip joint. The pipe is a tight fit at room temp, but as it heats up the pipe will expand more than the billet piece, and it will create a seal. Reminds me of how the SR71 was built. All the panel gaps didnt close up until above mach 2 when air friction caused the skin to expand and seal up.

Astonishing work Bobby and John!

Thank you Ian.

It has taken John a total of 200hrs to complete this Venturi, and the sad thing is its gonna be a one off as the die's have changed in the process.

[BOBBYr34]

It does look that way now that you mention it!

John sure has some serious skills and clever ideas.

Yes he sure is. Also we will be drilling the rb26 head to relief air locks . Will have detailed pics as i have a Rb26 sectioned head.

[STATUS]

10k for a manifold... holy feck!

id pay it for that kind of quality. One mans 10k is another 1k everything is relative. This is one of the best build threads ive seen in a long time.

love it.

[STATUS]

Below is a pic of the Fuel cooler. This is setup on the return line as we didnt want heated fuel to go back in to the surge tank.

Its very important that fuel temp is watched when using E85 as the expansion is 10 times greater then normal fuel. This can cause a dramatic change in the AFR, example if you tuned your car on a hot day now when you drive on a cold day, it will run lean. Now if you have tuned it on a cold day now on a hot day it will run rich. Basically your fuel pressure can vary.

No doubt you can use a fuel temp sensor and add a compensation, we run a similar fuel temp correction via the siemens ethanol content sensor.

[STATUS]

Yes very well put together thats if you want to run 98 and E85, what i am trying to do is only run E85 however as you know the concentration varies so we need to know the ethanol contant accurately . Tune can vary to fuel temp also when using E85 i have noticed he has not allowed for that.

haha sorry for 3 post in a row but if you look at my last post you will see the Link looks at both temp and content.... so atm it has 5 or 6 dimensional fuel and ignition tables.

[BOBBYr34]

id pay it for that kind of quality. One mans 10k is another 1k everything is relative. This is one of the best build threads ive seen in a long time.

love it.

Thank you

[mrchams]

http://motivedvd.com/motive/2011/06/30/in-the-build-jem-nissan-r34-skyline-gt-r/

[depalma-bcnr33]

gday bobby, before i say anything just want to say im a big fan of your approach to building your car and think its tops that youve comitted to building something different - and i hope it all turns out great.

1 question - in terms of not only cost, but also time, power and least disruption to exhaust flow would it have been a 'better' option to either

a) externally gate the wastegates pipes

b) if for road legal purposes, create a completely separate secondary smaller exhaust for the wastegates OR if using the same exhaust - join the wastegate pipes and main exhaust system further down i.e.: just before the cat (if there is one)

as opposed to creating the venturi...

dont get me wrong, i love what youve done think its f**kin great but just a question that crossed my mind when reading this - cheers

[GTRNUR]

Conventional manifolds will try and split the gas flow after the collector at a 45 degree angle, so that gas flow is able to be equally distributed between the turbine and wastegate. Few jap manifolds come close to this though. Mainly due to physical space limitations (my opinion).

The conventional approach is to use the wastegate gas tube angle and exhaust gas pressure to balance the flow of gas evenly through the wastegate and turbine in order to maintain a stable manifold boost pressure. The conventional approach is also meant to work with a typical turbo design where X size compressor wheel is matched to Y sized turbine wheel. This is not the case here with John and Bobby’s system.

John's deign is to allow a turbo with a smaller than typical turbine housing to be used on a large compressor equipped turbo without the issues of massively high exhaust gas pressures, boost control issues, and surging. The goal being to have greatly improved boost response, yet still have the capability to sufficiently control exhaust gas flow to keep boost stable.

For the sake of imagery, picture a GT40 size compressor wheel with a GT28 turbine size. (This isn’t what is being used but you get the idea). So the goal is to have the boost response of a 400hp turbo, yet have the turbo able to flow 700+hp on the compressor side.

The venturi is not about minimizing disruption of exhaust gas flow. While it does do that anyway by evenly distributing wastegate gas back into the main exhaust stream, the venture effect is to create a low pressure area in the wastegate gas piping in order to accelerate gas flow through the wastegates and to increase the scavenging effect from the wastegate ports in the merged collector. As RPM and gas flow increase, so does the efficiency of the gas wastegate control system.

Simply dumping the wastegate to atmosphere, or plumbing back in further down the front pipe will not be enough to sufficiently control exhaust gas flow with a radically trimmed turbo. Doing so would produce a very poor result due to bad boost control and higher than normal parasitic losses at the top end of the RPM range.

[BOBBYr34]

Wow thank you Ian for answering the asked question, all i can add to it is wasted gas is energy that has been used to do work.

Ian i think john has made the venturi so the turbine gases is low pressure and wategate pressure is high therefore this will extract gases from the turbine to make the turbo more efficient under boost i can ask him again, i understand where your coming form also.

100% agree on how you have explained the turbo selection as john said he wants ie 20% exhaust gas to drive the turbo to desired boost the rest waste. I guess the theory is all here just need to see it all happen.

Also i am in the process in installing all the Pressure and Temp sensors again another huge task as sensor placement has to be done all correctly as any data has to follow a trend and not give false reading due to incorrect placement, this will be all done with Johns guidance.

[r33_racer]

Excellent explanation. The idea behind the design seems fantastic for the goal trying to be achieved and it seems like it should work well. Ill be suprised if it doesnt.

Im interested to see what sensors you are using and what positioning John thinks is ideal.

[BOBBYr34]

Excellent explanation. The idea behind the design seems fantastic for the goal trying to be achieved and it seems like it should work well. Ill be suprised if it doesnt.

Im interested to see what sensors you are using and what positioning John thinks is ideal.

Yes it will work 100%.

I am using 8 EGT for each runner for tunning, the others are Pressure and temp exit of compressor housing, pressure and temp entry of intercooler pressure and temp exit of intercooler and finalli pressure and temp in plenum. These sensors will explain and confirm Johns theory sp we can see it.

Placement of sensors is the tricky one i still have to find out the rules and laws that will avoid false data, will ask john and get some pics up.

[BOBBYr34]

Conventional manifolds will try and split the gas flow after the collector at a 45 degree angle, so that gas flow is able to be equally distributed between the turbine and wastegate. Few jap manifolds come close to this though. Mainly due to physical space limitations (my opinion).

The conventional approach is to use the wastegate gas tube angle and exhaust gas pressure to balance the flow of gas evenly through the wastegate and turbine in order to maintain a stable manifold boost pressure. The conventional approach is also meant to work with a typical turbo design where X size compressor wheel is matched to Y sized turbine wheel. This is not the case here with John and Bobby's system.

John's deign is to allow a turbo with a smaller than typical turbine housing to be used on a large compressor equipped turbo without the issues of massively high exhaust gas pressures, boost control issues, and surging. The goal being to have greatly improved boost response, yet still have the capability to sufficiently control exhaust gas flow to keep boost stable.

For the sake of imagery, picture a GT40 size compressor wheel with a GT28 turbine size. (This isn't what is being used but you get the idea). So the goal is to have the boost response of a 400hp turbo, yet have the turbo able to flow 700+hp on the compressor side.

The venturi is not about minimizing disruption of exhaust gas flow. While it does do that anyway by evenly distributing wastegate gas back into the main exhaust stream, the venture effect is to create a low pressure area in the wastegate gas piping in order to accelerate gas flow through the wastegates and to increase the scavenging effect from the wastegate ports in the merged collector. As RPM and gas flow increase, so does the efficiency of the gas wastegate control system.

Simply dumping the wastegate to atmosphere, or plumbing back in further down the front pipe will not be enough to sufficiently control exhaust gas flow with a radically trimmed turbo. Doing so would produce a very poor result due to bad boost control and higher than normal parasitic losses at the top end of the RPM range.

I spoke to John today and he has confirmed it to do both, when spooling up this will work as a venturi for the wastegate and once on full boost wastegates will venturi gases from turbo, amazing one venturi however does two things. So you were right on what you had said and i was right what i had said.

[r33_racer]

Yes it will work 100%.

I am using 8 EGT for each runner for tunning, the others are Pressure and temp exit of compressor housing, pressure and temp entry of intercooler pressure and temp exit of intercooler and finalli pressure and temp in plenum. These sensors will explain and confirm Johns theory sp we can see it.

Placement of sensors is the tricky one i still have to find out the rules and laws that will avoid false data, will ask john and get some pics up.

These sensors will all just hook up to your motec?

[BOBBYr34]

These sensors will all just hook up to your motec?

Yes they call hook up to a motec with some extra expanders i think i have listed it all in my theard not sure what page it was

[BOBBYr34]

Here are some more pics of the development.

[waxracing]

Wow thats wild

[UWISSH!]

thats crazy.

looks like the turbo sits up realy high tho, how much bonnet clearence will you have?

[BOBBYr34]

thats crazy.

looks like the turbo sits up realy high tho, how much bonnet clearence will you have?

Sit's with heaps of clearance using the Nismo Z-tune bonnet