working out corrent manifold sizes for turbo conversion....

[asmeix6g]

hi all aminterested in converting a 3.0 inline 6 car engine to take a big turbo what formula is there for working out the optimum volumes for the inlet and outlet manifolds? obviously im going to need bigger injectors etc but ill get that done at a tuning shop with a rolling road. What are good turbo manufacturers? imlooking to get over 1bar of boost and hopefully somewhere around 16psi!
honestly im not crazy just power hungry

 

[Rubber Duck]

Unless you know exactly what you are doing I'd take the engine an expert IMHO.
It's not just about putting on a big turbo and larger injectors, to do it properly you will need to change the internals aswell; pistons, con rods, also lower the compession ratio, otherwise your engine will probably go BANG!

When you've done all that to get the power gain you want, then you need to upgrade the clutch, gearbox, driveshafts, diffs, brakes.

Not that I want to put you off, just some food for thought.

 

[gavuk]

I'm sure if you are going to turbo charge a n/a engine you have to reduce the compression ratio as well .this can be as simple as fitting a modified head gasket but needs to be taken into consideration,sorry can't help with manifolds ....Gav

 

[ngt]

There are 4 categories of boost.
0.4 - 0.8 - 1.5 - 2.0+

No1 Cheapest
No2 U dont have to get pistons
No3 Lots of bits and money.
No4 Extreme edition

Volume of your rmanifolds should be the least of your worries

 

[asmeix6g]

ok well... they do do a model of this car with a turbo on it. and the internals are the same but to find one thats manual with a turbo is hard as hell.. the blockand internals are the same. it will need a beller head gasket thats for sure. i know with a metal head gasket a lexus is400 inlet manifold 550 injectors and a 2.5"exhaust you can then increase the boost to around 17psi without any problems.
Im just asking about the volumes for the manifolds as i will get a better turbo (one thats not 20 years old!) then have the engine worked etc...

 

[JayRS4]

Give us a clue as to what the block is then, might be able to be more helpful. I can`t think what would take the manifold off a 1UZ, but guessing it`s a Toyota or Lexus, so maybe have a look on Lextreme or Planet Soarer forums for more info.

 

[asmeix6g]

supra mk3.... 7mge engine its soo hard to find a manual turbo which i want to do up anyway so i think i may aswel get an N/A engine and work a turbo onto it. there are alot of forums with alot of info about them but all most of them do is put a 2.5 or3" exhaust on an is400 manifold and 550 injectors then shim the waste gate! i want to go further than this..

 

[gaz_moose]

just buy a 7mgte to start with.messing around converting non turbo engines to turbo always ends up being a headache in the longrun.

 

[asmeix6g]

ah well i thought that BUT i want to uprate everything anyway and i guess by the time iv plumbed in an intercooler and all that i might aswel start from a fresh and do the lot at once. its not out of my capabilities! no way! i just want to work out optimun volumes etc..

 

[Pete.]

Just go for it. I'd size the turbo so that it can flow about 20-25% more than your target power. Make the manifold from 1.5" tube/bends. Plenum you can make from 3mm ally sheet - I wouldn't get too anal about the sizes just make one that fits comfortably in the space you have. Just about anything that will hold air will work.

 

[asmeix6g]

thanks for the advice pete seems alot of other people on here want to refuse me approval to fit a turbo to my car!

 

[malcolm]

thanks for the advice pete seems alot of other people on here want to refuse me approval to fit a turbo to my car!

I took those posts as useful advise - turbo cars do generally have a much lower compression ratio (8:1 for a properly boosted affair compared to 10:1 for a naturally aspirated car so that all that extra air can be added without detonation problems). You can ignore their advise if you wish but please don't have a go at them - they were trying to help.

 

[asmeix6g]

i know, i know BUT all i wanted to know was optimum volumes... the rest is down to me. there are reasons i dont just get the 7MGTE!

 

[Pete.]

If you're fitting a cooler you can run more boost on pump fuel or a bit more compression. The lower intake temps will help to stave-off detonation. I don't see any reason why you can't run 8 or 10psi on 10:1 compression with a cooler of you keep your fuelling suitably rich.

 

[JayRS4]

Or run race fuel if it`s not a daily driver. What about methanol or meth/water injection like a Devils Own/Aquamist system, might help keep the knock down and cool intake temps.

 

[Gunni]

hi all aminterested in converting a 3.0 inline 6 car engine to take a big turbo what formula is there for working out the optimum volumes for the inlet and outlet manifolds? obviously im going to need bigger injectors etc but ill get that done at a tuning shop with a rolling road. What are good turbo manufacturers? imlooking to get over 1bar of boost and hopefully somewhere around 16psi!
honestly im not crazy just power hungry

It´s not about boost numbers .
Those are irrelavent.

What POWER do you want to run

What power does it make now, are you going to run the stock camshaft?
ports and so on?..

Those are very important

The exhaust runners volume is less important then the type of exhaust manifold you plan on designing. I.e 6-1 , 3-1 for a split pulse setup?

Also what is the port size on the exhaust port of your head. not the valve but the port out of the head.