R34 Gtr Build

[BOBBYr34]

Fair enough, but saying that if you look hard enough you can pick faults with any design....

Firstly how much does the manifold/collector weigh? I would put it to you any gain made by the manifold would be offset by it's weight compared to a more conventional item.

Another example is where your collector merges the gases for the gates have to escape at a 90 degree angle to the flow. This used to be a issue with early 6boost manifolds that at high rpm the gas takes the least path of resistance and just bypasses the gates altogether creating boost creep all the way through the rev range. To fix this now all 6boost manifolds have a gate provision on a angle to flow the same direction of the exhaust gases. I think yours should be alright though because you are using twin gates but it could cause issues!

My main beef with the collector is where the 3 gate ports merge together. You talk of this as "to achieve the perfect merge and at the same time extract equal quantity of waste gases without causing extensive disruption to the flow." But if you think about the directions of the gas flow two of the extraction paths have to flow around 2 x 90 degree bends and while the other just has to travel a straight path. What's worse to this and in my opinion a huge design flaw is where these 3 gas paths merge... 2 are opposing each (blowing at each other) while the third is trying to push through the middle. This will cause major disruption of flow to all 3 paths and also a uneven balance. If you want a example of a better design look at a standard rb25 low mount cast manifold. It also has two opposing gas flows but internally it has a divider to direct the gases in the same direction before the merge to not cause issues.

Hope that all makes sense Maybe you can ask John his opinion on this?!?

Simon,

Its good that we all have this discussion as its all a learning curve for eveyone and i like how you have analyzed the merge collector.

Before i reply to your post i will ask some very simple questions so we are both at the same level.

You have quoted a major topic WASTE GATE. And yes i do remember problems with boost creep with 6boost manifolds. Now we have to get real technical.

1) what happens to air when you heat it - what happens to the density of air when heated? and what happens to the viscosity of air when heated ?

[SimonR32]

I assume your talking gases and not air? Air refers to the atmosphere... Gas would refer to what is in the exhaust manifold!

Gas when heated will either increase in volume or increase in pressure.

Density of gas when heated will decrease.

Viscocity of a gas increases with temperature.

[BOBBYr34]

I assume your talking gases and not air? Air refers to the atmosphere... Gas would refer to what is in the exhaust manifold!

Gas when heated will either increase in volume or increase in pressure.

Density of gas when heated will decrease.

Viscocity of a gas increases with temperature.

Air = 79% Nitrogen gas and 21% oxygen gas therefore air is a gas

I think what you are saying is a mixture of air with other impurites like unburnt hydrocarbons then it would not follow the laws of air as the viscosity will be inverted.

What we have in the manifold is air expansion or you can also call it gas expansion caused by combustion of hydrocarbons stoichiometric 14.7:1 = 14.7 Kg of air (nitrogen,Oxygen) need to burn 1kg of Fuel or 1L of air roughly 9500 L of air.

Look there is to much detail id have to list i will try and keep it simple.

F1, indy and rally cars are buit with extreme engineering that we will never find out as its all a big secret.

John knows all the secrets and willing to share it with anyone, this is why what i am doing is not normal, makes my build unusal and a higher chance of failure to a normal joe blow. what motorsport does we are not told.

John has worked with colin bonds cars, peter brocks race cars, he did work on the ford sierra turbo, built a race car for john masterton (masterton homes) he bought it of them and he owens it himself.

Below reply to your post

Getting back to the waste gate. A normal turbo setup people do like single turbo with wastegate needs as an example 99% of the gas flow to turn the turbo until desired boost level is reached then vent it through the waste gate.

With the setup john is doing as an example 30% gas flow to drive the turbo the rest waste so this will mean quick spool limited turbo lag. This is why he is taking wasted gas from each runner and there is no manifold out on the market that works like this unless you get your hands on.

"My main beef with the collector is where the 3 gate ports merge together. You talk of this as "to achieve the perfect merge and at the same time extract equal quantity of waste gases without causing extensive disruption to the flow." But if you think about the directions of the gas flow two of the extraction paths have to flow around 2 x 90 degree bends and while the other just has to travel a straight path. What's worse to this and in my opinion a huge design flaw is where these 3 gas paths merge... 2 are opposing each (blowing at each other) while the third is trying to push through the middle. This will cause major disruption of flow to all 3 paths and also a uneven balance. If you want a example of a better design look at a standard rb25 low mount cast manifold. It also has two opposing gas flows but internally it has a divider to direct the gases in the same direction before the merge to not cause issues."

Gas flow leaving through ports cut out, the calculated volume of three holes is the size of the cavity you can see that on the youtube vid. Also another point of thought is not all three cylinders will fire at once therefore the waste gate cavity will flow one at a time on each side not all three at once.

What you have said about the merge again not all cylinder fire at once the pulse do not interfere the aim is to fire as close as you can to the entry of the turbine housing.

I will have to look for a rb25 low mount turbo and i will show it to john.

I do want to say John had alot of problems in desiging the manifold, as the r34 gtr has limited space for the manifold.

The weight of the manifold i will weight it, trust me its light much lighter then a steam pipe manifold.

[BOBBYr34]

Here are some spec's of the motor.

Started the build from a N1 crate motor bought from Just Jap.

Motor was completely stripped down.

John Skola spec head porting

Tomei 260 procams 10.25 lift

Tomei Type c valve springs

Standard valves

side oil drain

Tomei cam gears

Greddy cam caps

Gates timing belt

Z-tune Stroker crank 2.8L

Crower Rods

Custom made Pistons from JE Pistons Static comp 10.1:1 ( I need to reconfirm this)

Dry sump peterson's 4 stage pump

Custom Sump

Os Giken triple plate clutch

PAR 6 speed full dogbox

Acpt carbon fibre tailshaft

Nismo intake plenum

12 Nismo 660 injectors (dual rail)

ARC cooler

Turbo is a turbonetics T70 with a T76 wheel inside it

Motec M800

Motec E888

Motec Expander

Exhaust Manifold john skola custom

[UWISSH!]

par dog box or ppg box???

[Granthem]

Wow. What a car. Impressive!

The manifold looks great. Who cares if you spent 10k. Its your money, not theirs. This will be an extremely unique GTR.

[tangomatt]

This build is going to be epic!

Certainly you have compiled a list of top class and unique components, I am looking forward to seeing it all come together.

Any consideration for V Cam?

Speaking from my experience, it is extremely helpful in helping you to achieve the objective of response, low end torque and early turbo spool up.

Is the build more street or track orientated?

Cheers

Matt

[BOBBYr34]

par dog box or ppg box???

par dog box 6 speed

[BOBBYr34]

This build is going to be epic!

Certainly you have compiled a list of top class and unique components, I am looking forward to seeing it all come together.

Any consideration for V Cam?

Speaking from my experience, it is extremely helpful in helping you to achieve the objective of response, low end torque and early turbo spool up.

Is the build more street or track orientated?

Cheers

Matt

Hi matt,

We did look into the V cam however the way the motor will be built with the correct cam timing and static compression this will work the same way. The car will be driven everyday, i will be drag racing it and track racing it just to show that you can build a car to do all the things.

As you might know i do own a Z-tune and driving that, has good response however this build is going to be alot more impressive

If you have other question more then happy to share my build with eveyone.

Bobby

[UWISSH!]

hows the PAR 6 speed dog box compared to everything else they build which seems to fall apart?

with the way the car is being built money wise i thort you would of went the ppg set or even hollinger? curious to know why you went with par?

[BOBBYr34]

hows the PAR 6 speed dog box compared to everything else they build which seems to fall apart?

with the way the car is being built money wise i thort you would of went the ppg set or even hollinger? curious to know why you went with par?

The par was the best option as ppg have had problems wth the 6 speed, hollinger i could of used with sequential changer would had to change front and rear diff and change the transfer case and the tail shaft for the front and again all three boxes can break.

Par i have had in the past and did have some issues with it, they have now fixed the problem and this box i bought is full dog engagement ( gonna have fun driving it lol ) I will be adding the ignition cut for quick gear changing.

[paulR32gtr]

Loving how this thread is turning out! Can't say I saw this coming from the first post... looking forward to seeing the results. Was very surprised to see the wastegate arrangement on the collector.

Nice paint job - is it standard Nissan KY0? Or did you get the actual z-tune paint from Nissan. After all my research I have not been able to nail down with certainty if the z-tune was a special one-off mix of KY0, or if it is the same stuff they subsequently put on 350Z's / 350GT's / Maxima's etc.

[PHaT MR30]

The par was the best option as ppg have had problems wth the 6 speed, hollinger i could of used with sequential changer would had to change front and rear diff and change the transfer case and the tail shaft for the front and again all three boxes can break.

Par i have had in the past and did have some issues with it, they have now fixed the problem and this box i bought is full dog engagement ( gonna have fun driving it lol ) I will be adding the ignition cut for quick gear changing.

Did you consider Modena? We too have had PAR in the past and had problems with it. While they were VERY good about replacing a COMPLETE gearbox under warranty (who else does that with motorsport products?), moving to a Modena this year in the new car was like chalk and cheese.

Im not going to tell you how to build your car cos it looks like you have far more of an idea about what you are doing than me!

Love the fabrication work on this so far!

[BOBBYr34]

Loving how this thread is turning out! Can't say I saw this coming from the first post... looking forward to seeing the results. Was very surprised to see the wastegate arrangement on the collector.

Nice paint job - is it standard Nissan KY0? Or did you get the actual z-tune paint from Nissan. After all my research I have not been able to nail down with certainty if the z-tune was a special one-off mix of KY0, or if it is the same stuff they subsequently put on 350Z's / 350GT's / Maxima's etc.

I had the whole car painted in KYO however the colour is correct but the difference is the way its sprayed on the Z-tune , not sure if you know i Do own a Z-tune and i can see a difference.

[BOBBYr34]

Did you consider Modena? We too have had PAR in the past and had problems with it. While they were VERY good about replacing a COMPLETE gearbox under warranty (who else does that with motorsport products?), moving to a Modena this year in the new car was like chalk and cheese.

Im not going to tell you how to build your car cos it looks like you have far more of an idea about what you are doing than me!

Love the fabrication work on this so far!

Hi Tim,

Thank you for the advise as i have never heard of modena, i just had a quick look at there website. If the PAR fails ill will make sure i make contact with Modena.

You sure can tell me what to do aqs this is why i have posted on the forum as i dont know everything but i do know alot.

Or if you have any questions about the build i will make sure i answer it as i am not hiding any secrets about his build.

[paulR32gtr]

I had the whole car painted in KYO however the colour is correct but the difference is the way its sprayed on the Z-tune , not sure if you know i Do own a Z-tune and i can see a difference.

Yeah I saw you mention that - figured you would be pretty much the best person for info on the subject seeing you have both the z-tune and the same car sprayed in the same paint!

[Risking]

Still planning to use that Ti exhaust we went and picked up bob?

I'm looking for one if you decide to not use it.

[DJRIFT]

i love this aproach to building or hand crafting cars. the modern generation of people like the bolt on option. if that option doesnt work they unbolt int and bolt somthing elce on.

i work with a bloke mad keen on old datsun L series motors and the lenghts they go to to make 5kw on a NA motor is extreeme. he has a few very good books on calculating air speeds for building runners and how tapering efects this. and so on. they also have mates that fill in the original ports and re drill ports in the head to make the air going into the engine more efficent.

the modern efi turbo engine has made people lazy as heaps of power can be achived cheap and easyily but its going the extra step that no one bothers with.

i like picking up the smaller points off people in motorsport that make the bigger difference at the end of the day.

good job sofar.

[BOBBYr34]

Still planning to use that Ti exhaust we went and picked up bob?

I'm looking for one if you decide to not use it.

Brad,

John loves the exhaust ARC you cant go wrong mate so i will be using it

[BOBBYr34]

i love this aproach to building or hand crafting cars. the modern generation of people like the bolt on option. if that option doesnt work they unbolt int and bolt somthing elce on.

i work with a bloke mad keen on old datsun L series motors and the lenghts they go to to make 5kw on a NA motor is extreeme. he has a few very good books on calculating air speeds for building runners and how tapering efects this. and so on. they also have mates that fill in the original ports and re drill ports in the head to make the air going into the engine more efficent.

the modern efi turbo engine has made people lazy as heaps of power can be achived cheap and easyily but its going the extra step that no one bothers with.

i like picking up the smaller points off people in motorsport that make the bigger difference at the end of the day.

good job sofar.

You are 100% right John in the past has welded up many ports and remade the design. He was going to redesign the combustion chanber on the rb26 however this would taken even more years to complete the build.

Quick Statement

NA motor - needs large ports

FI motor - needs small ports

NA motor- Needs volume

FI motor - air speed

Have a look at a indy car port size, its very small !!!!

John also stated a very important note about the RB26 - Very small stroke small cc very heavy car he did say this motor needed to be atleast a 4L for the weight R34 gtr is about 1680kg