R34 Gtr Build

[jangles]

Well I had a go at guessing lol.

This will be interesting to see! Just like every other bit of this build!

+1

[BOBBYr34]

Small update.

The manifold has been pulled apart to finalize any machining work and welding

I have some pics of the flange

[GTRNUR]

Great stuff Bobby. So I guess the pipes for the header slip inside the recess in the flange, and then they are internally tig welded?

321 stainless is an interesting material and it doesnt thermally expand in a linear fashon like many other common engineering materials. The hotter it gets the more its expansion rate increases. Will John be seperating each of the exhaust outlets once the welding is all done, so as to allow each header flange to move with the expansion of the head?

[r33_racer]

Hey Bobby, what size holes are in that flange for the exhaust studs? What sort of clearance does John allow for expansion as the flange grows? Im curious to hear his thoughts as usually you start off close to size in the centre of the head and then the hole clearance grows as you get closer to the ends of the head.

[BOBBYr34]

Great stuff Bobby. So I guess the pipes for the header slip inside the recess in the flange, and then they are internally tig welded?

321 stainless is an interesting material and it doesnt thermally expand in a linear fashon like many other common engineering materials. The hotter it gets the more its expansion rate increases. Will John be seperating each of the exhaust outlets once the welding is all done, so as to allow each header flange to move with the expansion of the head?

Hey Ian,

Yes John will tig weld internally.

John will seperate each exhaust outlet so it will be allowed to expand. He has some other ideas in his head that he has not mentioned to me i guess i wait and see what he will do.

[BOBBYr34]

Hey Bobby, what size holes are in that flange for the exhaust studs? What sort of clearance does John allow for expansion as the flange grows? Im curious to hear his thoughts as usually you start off close to size in the centre of the head and then the hole clearance grows as you get closer to the ends of the head.

Hey Michael,

I will measure it and let you know.

[ISL33P]

this is the best thread on the forum.....bar none!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (edit - actually any forum, including that Evo engine) Finally someone is building an effecient engine, not one that has a 2-3k powerband because anything like build is too few and far between....my hat goes off to John and yourself Bobby, this is fabrication and customisation in it's purest form.

Just one question, with all the effort that has gone into fabricating and designin the exhaust manifold and exhaust system, what is planned for the intercooler, piping and inlet manifold? There is plenty of f1 style technology that improves these areas just like you both have with the exhaust.

Cheers,

Ariel

PS - you bet your bottom dollar I am subscribing

Edited January 9, 2012 by ISL33P

[6BOOST]

Hey Guys,

Thought I'd chime in and say I've known Bobby for a number of years now and we discussed this manifold the very first time we met. He has been a great supporter of our products and certainly isn't here to bag 6boost, and thank you Bobby for the kind words on the quality of our product. Whether anyone see's the benefit in his design is irrelevant, this project is being built for one person and it's the same person paying the bills, so maybe cut him a little slack and appreciate that rather than wait and see IF it works, he's putting his rep on the line and showing everyone the full build DURING the process, if nothing else the level of thought and engineering warrants commendation.

I believe there will be a few other factors in engine design that will help with spool in this combination, and while I appreciate the effort gone into equal wastegate flow, I am still sceptical at its hp improvement over conventional design, hopefully even if it doesn't achieve your ultimate expectations we still get to see the real outcome and response. If it doesn't meet your expectations, at least you put your money where your mouth is and tried, more than I can say for 99% of the rest of the performance industry who just copy and regurgitate the competitions product over and over.

Glad to hear the end is finally in sight guys, good luck with finishing the project and I look forward to seeing your results.

6BOOST

[BOBBYr34]

this is the best thread on the forum.....bar none!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (edit - actually any forum, including that Evo engine) Finally someone is building an effecient engine, not one that has a 2-3k powerband because anything like build is too few and far between....my hat goes off to John and yourself Bobby, this is fabrication and customisation in it's purest form.

Just one question, with all the effort that has gone into fabricating and designin the exhaust manifold and exhaust system, what is planned for the intercooler, piping and inlet manifold? There is plenty of f1 style technology that improves these areas just like you both have with the exhaust.

Cheers,

Ariel

PS - you bet your bottom dollar I am subscribing

Hey Ariel,

Thank you for the Comments

The intercooler we are using is one of the topof the line ARC i think there are pics early in the thread. and the piping kit is all custom 80mm i had to make them myself, as you cannot buy 80mm internal diameter in Aluminium pipe and bends. John made three nylon balls each started from i think 77mm to 80mm and i pulled them through a 76mm pipe cold using a hydralic chain system. I might have some old video's on this i can post. Inlet manifold we are using is a Nismo Intake that John checked along side others and found this to do the job. John did do flow test on this manifold.

As we all know the factory manifold has a mistake in it giving rear cylinders upto 16% more airflow.

[BOBBYr34]

Hey Guys,

Thought I'd chime in and say I've known Bobby for a number of years now and we discussed this manifold the very first time we met. He has been a great supporter of our products and certainly isn't here to bag 6boost, and thank you Bobby for the kind words on the quality of our product. Whether anyone see's the benefit in his design is irrelevant, this project is being built for one person and it's the same person paying the bills, so maybe cut him a little slack and appreciate that rather than wait and see IF it works, he's putting his rep on the line and showing everyone the full build DURING the process, if nothing else the level of thought and engineering warrants commendation.

I believe there will be a few other factors in engine design that will help with spool in this combination, and while I appreciate the effort gone into equal wastegate flow, I am still sceptical at its hp improvement over conventional design, hopefully even if it doesn't achieve your ultimate expectations we still get to see the real outcome and response. If it doesn't meet your expectations, at least you put your money where your mouth is and tried, more than I can say for 99% of the rest of the performance industry who just copy and regurgitate the competitions product over and over.

Glad to hear the end is finally in sight guys, good luck with finishing the project and I look forward to seeing your results.

6BOOST

Hey Kyle

Thanks for the comments.

Yes its been exactly 3 years i met you at palm beach cruise with PJ.

No problems mate your manifolds are the best over so many makers out there. This is not coming form me its coming from John.

Once we get this build close to finishing i sure you will get to the results of the Exhaust manifold John has made for us ( this is for everyone) .

[Raysboostin]

Wow what a read!! Firstly id like to say to you bobby that u are quite possibly the most forward thinking guy in the aussie car scene! Its because of guys like you that we have the mods available to us off the shelf. Im glad someone is interested in pushing the limit of the performance of the RB motor. The any gear, anytime approach to performance is a favorite of mine and hope to build mine in a similar way.

I am curious about a few things

Firstly, how come you went 2.8 rather than a 3L?? I would have thought more cc's would have helped??

Secondly why go with the 321 stainless?? Arent stainless manifolds normally made of a different grade steel than 321?? Keep up the good work.

[ISL33P]

Just in relation to intake manifolds and intercoolers, dont you think there are better designs out, much the same reason why you (and/or John) belived a different exhaust manifold was required? I mean, there are much the same benefits available from improvments on the inlet side as there are the outlet side......to me it just seems like there is the other 50% of the equation which is untapped. No doubt that Nismo and ARC are well renowned "mass produced" products for the "masses" but this build requires something different to that.

I know you mentioned this is what John has recommended, but has it not crossed your mind....maybe it's just because this is the side I concentrate on......just a thought, in no way am i having a go just wondeiring why it has been explored?

Just in regards to the Nismo plenum, has it been flow tested it? With the larger volume at the rear, I would think that flow would increase, maybe in direct relation to the rest of the runners, but again, it may increase more over the others due to this increase area especially around cylinder no6??? Again, im just want to hear other people's experiences

Cheers,

Ariel

Here is what the rally and f1 teams of the 80's used to do

edited to not cause misreading

Edited January 13, 2012 by ISL33P

[GTRNUR]

I do wonder about that comment that the rear cylinder gets more air with the standard plenum. How much of it is marketing, or wording lost in translation from Japanese to english, or just "internet regurgitated knowledge".

Perhaps this is the case when off boost, and air velocity at the ports is more of a factor which could be a concern to those still perservering with 2.6lt.

But when its on boost and your blowing 25+psi into the manifold, the restriction is the intake manifold base plate and intake port. Provided all the ports are matched in theory there should be an equal pressure drop across the port to the base of the intake valve for all cylinders.

Given an opportunity to change the manifold to something else, I'd go for a Greddy 2 piece manifold. That way I could I can run a second set of 6 injectors or individual port water/meth injection and have the added advantage that the individual throttles could be match/balanced with a vacuum meter. When you have 6 port EGT monitoring you can tune around the few percentages of variation easily enough.

[ISL33P]

according to some experts it is because of the water temperature difference between the front and rear of the block.....I dont doubt the numbers about the mismatch of flow considering some of the variances I have seen in factory manifolds of up to 20%!!!!

Here you go GTRNUR - Greedy flow test results

Edited January 13, 2012 by ISL33P

[GTRNUR]

according to some experts it is because of the water temperature difference between the front and rear of the block.....I dont doubt the numbers about the mismatch of flow considering some of the variances I have seen in factory manifolds of up to 20%!!!!

Here you go GTRNUR - Greedy flow test results

The water temp differences between the front and rear of the block will affect fuel atomization and vaporization but not airflow. Over 100 degrees the variation in the size of the intake ports will be about 2.3 thou, which is barely measurable. Considering the cylinder head will at worst have only a few degrees of temperature variation from front to back, you couldn't possibly measure it. The improved vaporization effect in the hotter cylinder means that if you injectors are 100% perfectly matched, the rear cylinder will run a little lean for any given AFR. Something which is easily corrected for with an injector trim.

Do you know how those flow results were measured? Was it a complete intake from plenum to head and measured at the combustion chamber?

I still wonder about the merits of worrying about this sort of data. Given that once that plenum is pressused and provided the head porting is all matched, there shouldn't be a variation in pressures seen at the back of the intake valve, and hence any flow variation either.

To me what this means is that in an off boost situation and when the throttle is snapped open, some cylinders will obtain slightly better airflow. Which means that there will be a slight variation in cylinder pressures and resulting torque produced in each cylinder. This on paper would also require slight variations in fuel and ignition to achieve the optimal result. But having said that considering the airflow in a vacuum or wide open throttle(yet off boost) situation, the variations in injector pulse and ignition advances required to correct for this would be extremely small and barely worth correcting for. After all, how long can you hold WOT till the engine starts making boost.... not long.

If only someone could flow test an intake manifold with 25psi of pressure pumping into it, instead of just pulling 25"Hg of vacuum through it.

[ISL33P]

I havent seen any evidence to prove the water theory, but I will be glad to see it.

Flow test is done just on the manifold alone. The final results really depend on the given cylinder head but these will simply be a percentage of the manifold flow and ie head and manifold flow combined will have similar, if not the same, variances as the manifold alone since the head flow is theoretically the same between cylinders.

Just a few points to remember:

- pressurised or not, airflow direction, turbulence and swirling will remain the same regardless

- Boost pressure only increases the air density not overall airflow. More air density is what makes the more power, not more airflow

- Air speed at peak is the same N/A or forced, it just reaches peak quicker in forced applications

Plan is to have manifold flow tests (mine and others) on and off a bone stock cylinder head I have here once I complete my rb26 manifold.

Anyway, I dont want to make this about airflow we can do that in another thread. Let's leave this for thoughts and progress on this car, back to you Bobby.

Cheers,

Ariel

[DCIEVE]

I'm surprised there is still talk about #6 running lean considering how many people are logging individual cylinder EGT proving fairly conclusively (IMO) that the opposite is true.

For a start the corrections required to balance EGT vary dramatically on and off boost.

[ISL33P]

remembering it's air density, not flow and that you are chasing different target AFR's and EGT's throught the whole operating range and therefore the corrections will vary depending on what you want to achieve

[BOBBYr34]

Wow what a read!! Firstly id like to say to you bobby that u are quite possibly the most forward thinking guy in the aussie car scene! Its because of guys like you that we have the mods available to us off the shelf. Im glad someone is interested in pushing the limit of the performance of the RB motor. The any gear, anytime approach to performance is a favorite of mine and hope to build mine in a similar way.

I am curious about a few things

Firstly, how come you went 2.8 rather than a 3L?? I would have thought more cc's would have helped??

Secondly why go with the 321 stainless?? Arent stainless manifolds normally made of a different grade steel than 321?? Keep up the good work.

Thanks Ray,

I will continue beingopen about my build as its not just for meits for everyone.

The reason we went 2.8L so it could rev and a 3L dont like to rev and the block is not designed to have a diff sitting under it. If John had the choice on L he would want it to be a 6L.

321 Stainless has titanium in it, to help handle high temps better than other stainless grades.

[BOBBYr34]

Just in relation to intake manifolds and intercoolers, dont you think there are better designs out, much the same reason why you (and/or John) belived a different exhaust manifold was required? I mean, there are much the same benefits available from improvments on the inlet side as there are the outlet side......to me it just seems like there is the other 50% of the equation which is untapped. No doubt that Nismo and ARC are well renowned "mass produced" products for the "masses" but this build requires something different to that.

I know you mentioned this is what John has recommended, but has it not crossed your mind....maybe it's just because this is the side I concentrate on......just a thought, in no way am i having a go just wondeiring why it has been explored?

Just in regards to the Nismo plenum, has it been flow tested it? With the larger volume at the rear, I would think that flow would increase, maybe in direct relation to the rest of the runners, but again, it may increase more over the others due to this increase area especially around cylinder no6??? Again, im just want to hear other people's experiences

Cheers,

Ariel

Hi Ariel,

John did start making a manifold however we had to stop, as this motor was going into a R34 Gtr V-Spec II Nur and John needed the Clutch booster and brake booster moved as they were in the way, when he say the car he said no way this car is to nice to do those mods. He did tried making the number 6 intake runner like a cops tail it started to get out on control and would of taken more years to finish.

This is where john liked the Nismo manifold as he could see how they fixed it from the stock manifold, and the nismo runners are longer then factory and we were able to set up another bank of injectors on the underside. The nismo manifold has the hard work already done for you.

Arc do not make coolers in mass production they only make to order ( i should say they used too as the business has closed down) the cooleri bought is a special make drag cooler with a very high heat soak ability at low vehicle speed.