new exhaust details

[chefdave]

Hi
read the forum on pipe diameters which tie in with reasults of another website. currently my exhaust is 1/2 under factory diameter. so going with slight increase indiameter.1/8th of an inch as easier to get this pipe diameter. going to have no silencers at front part of exhaust and fit to silncers to rear most exhaust. this i havr read somewhere on net helps to improve low end torque. my engine is oversquare so not a great low down torque. peak hp comes in at 144hp at 4800revs. very unsual on a petrol engine. pipe diameter has i am going to use already been proved on same car. as you say bottom end torque is better than high rpm horse power.

[California98Civic]

so i think you're saying that you read through http://ecomodder.com/forum/showthrea...ead-20689.html and you are doing a complete exhaust tune. Is that correct?

[chefdave]

Yes going to do whole system from where cat was fitted. will keep pipes as straight as possiable. silencers will be true flow through. need two silencers to keep noise undercontrol. have one standard silencer at moment noise is not excessive but listerning to other cars sounds a little louder. a slight power increase will help with auto box to stay locked up.

[California98Civic]

Sounds good. Post pics and details. Would like to see the products and the install and such...

[chefdave]

Hi california civic 86
Will be doing planning and costs in new year when am in hospital having a shoulder injury operated on. will try to use stainless steel for lighter weight and longevity. will use 2 1/4 inch pipe instead of factory 2 1/8 inch. at present exhaust diameter is 1 3/4 inch which is far to small for a v6 3.0 litre petrol. other toyota owners have used 2 1/4 with good reasults. will post photos of before during and after.

[mcrews]

According to the chart referenced in the exhaust thread 2.25 is for 188 hp max. Your going too big.
So I'm confused???
It's like you didn't read the thread....
Your at max 144 hp MAYBE 2-3% of your life time so the pipe you say you are using is over kill and too big.!

How do you figure to achieve "power increase"??

[chefdave]

Hi mcrews
yes you are right with table pipe dimensions. my engine is a odd ball. toyota strangled the engine. been on a website that is specific to toyota hilux 4runner etc. everyone who has fitted a 2 1/4" diameter pipe has had a hp increase and lower fuel consumpsion. if i elminate the manifold cross over pipe then hp will jump even more and fuel consumpsion will drop again. removing the m cross over manifold pipe solves head gasket issue. theroy says it increases power from tick over all the way to 5000rpm. what im looking for is more torque which means less gear shifting on auto box. autos love lots of torque. as my motorhome is over 2.5 tons torque is more important. the longer i can stay in overdrive the more fuel i should save. ultimate option is to fit a 3.4 v6 this is far better on fuel than 3.0 it was derived from. that is opposite to what should happen ie bigger engine should burn more fuel.

[mcrews]

good luck!

[Arragonis]

Are you really in John O'Groats ? If so then Hi

HP and Torque are the same thing really.

Mr Duckworth (the "worth" in "Cosworth") expressed HP as "size of bang multiplied by number of bangs". So think of "size of bang" being the same as torque. To improve that you will need to :

- Increase the amount of air in the cylinder (so you can efficiently burn more fuel)
- Decrease the temperature of the air in the cylinder (so it is more dense, and you can efficiently burn more fuel)
- Reduce parasitic energy losses such as the energy required to fill a cylinder on the induction stroke and the energy required to empty a cylinder of exhaust gasses.
- EDIT - Reduce electrical load. No A/C, LED lights etc.

Yours being the "truck" engine doesn't have any other clever trickery such as VVT or multi valve heads - it is designed for reliable "slogger" torque and as little looking after as needed.

Your new exhaust may give you the latter option but even then the effect is going to be blunted by the rest of the induction / exhaust system - the valves, head ports, manifold etc. I suspect all you will have is a rust proof exhaust and a rather annoying "moooooooooooooooooooo" noise as you plod along, and nothing else.

You may be able to decrease the temps with a CAI and an air filter but probably not as, again, the rest of the induction/FI system will bring temps back to more or less what they were before without lots of work. Been there, done that.

If you really want to increase torque I would ponder forced induction of some kind - more air squeezed in, more fuel burned and a bigger bang when you need it.

Also (I've suggested this on other threads but...) maybe a swap to a Diesel motor (there was a 2.4D in the Hilux here) or better still a TD would be preferrable but that depends on how cheap they are where you are, the cost of conversion (not forgetting gearing) and how long you want to keep the vehicle.

[chefdave]

Hi arragonis
yes i live in groats. i understand whst you are saying about torque and hp. cosworth produced many stunning engines so mr ???worth is an expert. my truck comes with a cai as standard from toyota air is drrawn in via front headlight housing. i have removed the air intake silencer and made a shorter and smoother passage for air from air box to throttle body. would like to go down diesel route but toyota diesels in early hiluxs were known to crack heads for a past time. best diesel engine i know for slogging is nissan 2.7td 125bhp and 210 lb/ft of torque also very easy to increase power without breaking. another diesel would be 3.1 diesel out of trooper again another engine easy to tune.
forced induction is out on my 3.0v6 as head gasket will blow know of no one who has had sucess. at moment my engine sounds like a v8 ummmmm nice sound.
I only plod up hills going down is no prob except trying to observe speed limits. have you ever driven the berridale bends very interesting in an auto lock it in 2nd all the way down.