Exhaust port length

[Lambo]

I have been playing around with the Headerdesign.com calculator, the headers i bought from a local guy were home made 4 to 1 with 1.6 ID and are about 36" to the front of the collector cone.
Does anyone have a head off that could be measured i need the exhaust port length from the valve seat to the flange for a 1uz.
I have had a good search but can't find it on the site.
Jbrady suggests 1.6 I/D primary tube is two big and i tend to agree, The program suggests 1.2" ID primaries, my setup may end up with 2 turbos or not, so could i go with 1.2 for N/A , or 1.6 for turbos, seems a shame to dump the existing 1.6 headers, also does anyone understand what they mean by collector inside diameter ,they give you a figure of 1.92 do they mean this is the size of the collector body where the reducer meets the collector tube, as shown in their schematic.
As you can see below i have set the hp @250 at 5600 according to the 1uz spec page. I am aiming for peak HP at about 5000.

Regards
Lambo

 

[Zuffen]

Using a piece of string the figure I got was 68mm on the short side and 98mm on the long side.

Hope that helps.

 

[Lambo]

Thanks for doing that for me Rod, it will help heaps, do you have a thought on the 1.28 v 1.6 id tube i was working on the theory that 1.28 if i go N/A or 1.6 if i go twin turbos, from other articles I have read equal tuned length on the NA can make a big difference, but if it was turboed the length is not so critical as the pressure waves are quite different, and maybe the bigger diameter tube would be needed to shift more air, i guess it comes down to having torque at low rpm as a N/a or being able to get the air out faster for a turbo at higher RPM any thoughts.

Best Regards
Graeme

 

[Zuffen]

My thoughts are the larger size makes more sense with the turbo. The engine should be flowing a lot more air ina turbo engine than a an N/A engine so going up in pipe size makes sense.

Why not PM JBrady as he knows his stuff.

 

[cowboy bebop]

It's a tough call on piping diameter. 1.5" ID exhaust ports are massive. Do the manifold runners need to be 1.5" ID? Maybe so, maybe not. Consider that the 2jz makes all the power that it does with exhaust ports smaller than a Honda D series. I would personally think that something as small as 1" ID would flow enough to make the 4 digit HP, and improve velocity enough to provide a noticable gain in spool time by taking advantage of the venturi effect.

Just my opinion,

Eric

 

[GSMnow]

My 22RE turbo motor had a unique manifold setup. I used the stock cast iron 4 into 2 section that had about 1.2 inch id ports at the head and 2 holes about 1.4 inches at the bottom. It was fairly smooth inside and was a proper 1/4 2/3 pairing with about 14 inches from each port to the flange. I then made a flange to fit and used a pair of 1.4 inch id pipes ( I used Schedule 40 steam pipe weld bends ) that ran about 18 inches and Y'd together like a collector into the turbine housing inlet. I used a smallish .48 A/R T3 exhaust housing with a Turbonetics stage 2 wheel. The compressor side was a TO4E 60 trim which was actually too big for the motor as I just got into peak efficiency at 6,000 rpm as the cam was falling off. I did rev it out to 7200 in autocrosses though to avoid shifting to third. The motor was 2.4L, so a bit bigger than half a 1UZ, but it also was just single cam 2 valve, but with a 268 degree cam (223 degree at .050 lift). It would come on boost very hard starting before 3,000 rpm. Without boost this motor made about 165 hp and made around 300hp at 13 psi. Compression was caculated at about 8.4 from the head and piston volumes, but it still pumped over 145 psi cranking. If I was going to do it over again, I would go with a 260 degree cam and a TO4E 45 trim as it would come on boost at 2500 rpm or even lower them. All of my intercooler piping was just 2 inch. I ran a 2.5 inch mandrel bent exhaust after the turbo with a CatCo 2.5 inch convertor and a DynoMax Ultra flow muffler.

Gary M.
Changing my Celica from 2.4 turbo to 4.0 NA
I will miss the boost, but not the lag.

 

[Toysrme]

Does the calculator error out for everyone now, or does it still work?
I can't do anything useful on the entire site.

 

[Lambo]

Hi Toysrme, same for me rest of site goes ok but calculator broken, must be Xmas hackers.

Best regards
Lambo

 

[Toysrme]

I figured it was broken for acouple of months. They just don't return emails LoL!