Individual Throttle Bodies and Improved Airflow - Page 25

Dessertrunner · #**361** 04-24-2011, 07:31 PM

I think I need to flow test the throttle to work out what is best.
Tony

Dessertrunner · #**362** 04-25-2011, 11:25 PM

Okay here is a new design that fits the injectors in the current position. Before I go much further I need to get the ram pipes I have been waiting on them so I can check clearance, also they maybe strong enough for me to mount the injectors above the rollers as Adam & Harvey have suggested. Also waiting on reamer for the existing throttles.
The 3 intakes in the pdf are all different positions.
Have a great day.
Tony

Dessertrunner · #**363** 05-08-2011, 02:53 PM

So I started machining the new design yesterday here is where I am up to so far, all the rollers are made except that I need to cut the port through when I go to final intake shape. Its a bit tough trying to get a balance between the amount of clearance at in the roller pocket and the roller moving freely. Also making sure the bearings all fit on the shafts as well. Need to make allowance for expanision of all the metal when it gets hot.
Tony

oab_au · #**364** 05-08-2011, 05:05 PM

Thats a great piece of machining Tony, and you grow vegetables for a living.

Harvey.

Dessertrunner · #**365** 05-08-2011, 06:06 PM

Quote:

Originally Posted by oab_au

Thats a great piece of machining Tony, and you grow vegetables for a living.

Harvey.

and got expelled from school.

oab_au · #**366** 05-08-2011, 07:24 PM

Quote:

Originally Posted by Dessertrunner

and got expelled from school.

Oh,

You too, that would be right.

Harvey.

dynomatt · #**367** 05-08-2011, 07:44 PM

Haven't logged in for ages, but you've done some great work Tony. Keen to see more progress.

Matt

Dessertrunner · #**368** 05-08-2011, 08:48 PM

Ram pipe were shipped from the UK on Friday so they may be here late next week. As soon as the pipe gets here I will ship a roller throttle to Mark for flow testing.

Also have developed a design to be made from radiator pipe. It has a inside ID of 38.5 mm as oppoased to the 42mm on the pipes from the UK. GIven what I have been told the home made design maybe better at low revs.
See pdf
Tony

Dessertrunner · #**369** 05-17-2011, 05:18 PM

High guys have been milling more parts for the new throttle bodies. Haven't had time to post photo but will.
I am at the stage were I need to mill the injector ports at 35 degrees. Last night I set it up ina angle vice but Its not strong enough the stop the throttle body moving so I will need to work out a different approach. My guess is I will need to build a jig to clamp direct to the chuck or something simular. Anyway will keep you posted.
Tony

dynomatt · #**370** 05-17-2011, 05:47 PM

tony,

Can you explain your ram tube design a bit more please? Is it made of rubber? Or are you getting ones like the alloy ones made with the curve?

Matt

Dessertrunner · #**371** 05-17-2011, 06:22 PM

Hi Matt,
I have the ones coming from the UK which I hope will arrive today. They are 42mm ID but my guess is they maybe to high for the current intake design.
The home made ones are 38.5 ID what I am working on is using a 90 degree aluminum bend from one of the radiator guys and then mill a intake flange to be spot welded on. On the weekend I worked out there length will be about 400mm from valve to face of ram pipe.

I was going to ask you and Harvey what length you think I should go for? I would like maxium power at 6,000- 7,000 rpm.

One point I think changes the whole dynamics of the air going into the engine is that if the ram pipes are designed correctly the air is going into the head at a lower vacum and at time a postive pressure.
This as opposed to the standard intake which is at a larger vacum. The higher the vacum the lower the amount of air per given cubic volume. I personally thing this maybe were the change in throttles gives a major advantage.
Tony

dynomatt · #**372** 05-17-2011, 06:40 PM

I found ages ago an inlet length calculator (maybe this one? http://www.rbracing-rsr.com/runnertorquecalc.html)...I can't exactly recall what it said sorry. As you know, the shorter the length, the better it is at higher revs. I think Harvey would know the maths behind it, but I don't sorry. something to do with resonant waves etc...I'm not smart enough for that.

I think you saw photos of my design didn't you? Using silicon hoses. They worked OK, but no idea of their longevity. I used silicon hoses so I could more easily change the length of the system on the dyno to find the optimum. Didn't quite get that far though.

An airbox (or 2) would deliver the optimum result. There's maths which can calculate the optimum volume, which will also deliver a cooler charge. I think it's something like twice the engine capacity. but that might be a 4 cylinder thing.

M

oab_au · #**373** 05-17-2011, 07:20 PM

Quote:

Originally Posted by Dessertrunner

Hi Matt,
I have the ones coming from the UK which I hope will arrive today. They are 42mm ID but my guess is they maybe to high for the current intake design.
The home made ones are 38.5 ID what I am working on is using a 90 degree aluminum bend from one of the radiator guys and then mill a intake flange to be spot welded on. On the weekend I worked out there length will be about 400mm from valve to face of ram pipe.

I was going to ask you and Harvey what length you think I should go for? I would like maxium power at 6,000- 7,000 rpm.

One point I think changes the whole dynamics of the air going into the engine is that if the ram pipes are designed correctly the air is going into the head at a lower vacum and at time a postive pressure.
This as opposed to the standard intake which is at a larger vacum. The higher the vacum the lower the amount of air per given cubic volume. I personally thing this maybe were the change in throttles gives a major advantage.
Tony

For the Max power to between 6 to 7000 rpm, the torque would have to be at about 5800 to 6000. about 1000 rpm higher than the standard 4800. I would say about 350mm, Matt used 300mm I think, but we don't know where that had the torque peak happening. The standard lengths were all different to spread the torque over a wider rev range, yours will all be the same length, so the spread will be narrower.

Quote:

One point I think changes the whole dynamics of the air going into the engine is that if the ram pipes are designed correctly the air is going into the head at a lower vacuum and at time a postive pressure.
This as opposed to the standard intake which is at a larger vacum. The higher the vacum the lower the amount of air per given cubic volume. I personally thing this maybe were the change in throttles gives a major advantage.

The pressure in the inlet does change from high to low as the sound waves move through the system, but this does not mean the there is less air contained in the cylinder. The vacuum created in the cylinder by the pressure waves, mean that more air is induced into the cylinder becase of the pressure difference created between the outside atmospheric, and the inside vacuum. It is the reverse of having a high pressure outside the cylinder pushing air in.

The big increase is due to the shorter intake raising the maximum air flow to a higher rpm, so more HP is produced.

Harvey.

oab_au · #**374** 05-17-2011, 07:59 PM

Quote:

Originally Posted by dynomatt

I found ages ago an inlet length calculator (maybe this one? http://www.rbracing-rsr.com/runnertorquecalc.html)...I can't exactly recall what it said sorry. As you know, the shorter the length, the better it is at higher revs. I think Harvey would know the maths behind it, but I don't sorry. something to do with resonant waves etc...I'm not smart enough for that.

I think you saw photos of my design didn't you? Using silicon hoses. They worked OK, but no idea of their longevity. I used silicon hoses so I could more easily change the length of the system on the dyno to find the optimum. Didn't quite get that far though.

An airbox (or 2) would deliver the optimum result. There's maths which can calculate the optimum volume, which will also deliver a cooler charge. I think it's something like twice the engine capacity. but that might be a 4 cylinder thing.
M

Link did not work. This one does, but I don't agree with it, there is no consideration of length.

http://www.rbracing-rsr.com./runnertorquecalc.html

The formular for the resonate length is: No of degrees for the wave to return to the cylinder X the speed of sound in the inlet gas, divided by the rpm that you want the negative pressure to be in the cylinder.

All this depends on the cam timing and the actual valve opening time, and the rpm that the exhaust negative wave reaches the cylinder.

Harvey.

Boxersix · #**375** 05-17-2011, 08:43 PM

What are you factoring in for taper in the throttle bores and the ram pipes(v-stacks)??? I've always calculated in about a 1.5% taper per inch in these type of setups to maintain laminar flow throughout the induction system. Many shrug off taper as being a useless/unnecessary variable in the designs of these "grassroots" setups but it really is not the case.

Just curious.

Also, have you considered composite ram pipes of your configuration? Now that you have a CNC you can mill you own molds and go nuts.

It's what I do. Screw sticking to the off-shelf stuff now that you have the equipment