OK, All tips & Tricks To Build A 2.6 Turbo

[MainstreaM]

don't mean to spoil the party but no one brought heat into the equation.  exhaust temp has a lot to do with spool.  Thermodynamics of expanding gases.

 

kane

[johnfjamerson]

don't mean to spoil the party but no one brought heat into the equation.  exhaust temp has a lot to do with spool.  Thermodynamics of expanding gases.

 

kane

 

EXACTLY!!!   ----expanding gases in a smaller space increses the offset of normal gas(or, in this case, cooler already spent exhaust). That is how an engine works in the first place. Think high compression vs low compression, same a/f charge but less space vs more space. the smaller space wins the contest because the same pysical amount of gas is pushing against the piston from a smaller space. more pressure of expansion. it is also acting on the turbo before it even gets there, exanding gases, moving the only way they are alowed to which is through the turbo down the stream. this is also the reason back pressure is around. (to much is bad, and is a restriction) but with the correct amount of pressure, you can calculate what the velocity of the gas is at a specific point of revs. if you dont have any, well, that means there is not enough expanding force to move anything at high speed.

Even after the turbo, the gases still expand and continue to flow. You get them(gases) to move the hell out of the housing as fast as posible, (same AMOUNT of gas, in big Vs. small diamiter) the smaller pipe will move the gasses faster. When i say faster, I mean speed, not overall flow. when you can actualy get the gasses moving faster, what do you think moves faster with the gases? the turbo!!! bing bing bing!!!

 

Example.... you know those little wind mill things on a stick that are made out of foil? open your mouth about the size of a quarter, and let ALL your breath out at it. blah right? doesent move very fast at all. now pucker your lips like your gonna whistle and the same amount of air (in you lungs) makes a faster moving stream of air. the damn things spins faster.

get it?

 

dont get me wrong, 3" will flow way more than a 2.5" pipe. 44% more to be exact. (and a 2.5" flows 56% more than a 2") Take a pipe of each, 3 feet long. they will both move 500cfm easy. but when you put the air to it, which pipe, (in terms of speed) will flow the air from one end to the other faster?(remember speed, not flow) the smaller pipe will.

 

with a 3" or a 2.5", the amount of gas coming out of the head is the same. to get the gas from the port to the tail pipe as fast as posible, you want the 2.5". its just the way it works. when you go big, and use more air, like bigger turbo, nitrous, and more boost, that means more gases. then you want to FLOW more.

 

eh?

[Lizzord30]

I belive that Conquest351 is going too a T3/T4 turbo that is fairly good sized, i dont think 3in will be too big, what he may want too do is exhaust wrap the header (i know it will die fast but their is gain also) get a blanket for the exhaust housing and wrap the down pipe, too keep the temps up (or at lest keep the engine bay temps down). If anyone has the stock exhaust side i dont think a 3in mendral bent exhaust pipes will out perform the 2.5in mendral bent pipes asooming they are the same quality.

[Conquest351]

Yes, I am going to Ceramikote the exhaust runners in the head itself, the exhaust manifold both inside & out, the turbine side of the turbo both inside & out and the downpipe.  I think this will aide in keeping the heat where I want it.  LOL  I am also aware of flow and increasing flow and velocity.  I am really just looking for little tricks in the build process.  Like, if you take this out or open this up a little, it helps so & so and therefore you get better oiling, or air flow or something.  If you drill out your oil return hole to so & so it helps tons.  You know what I'm talkin about?  Anyways, the things you guys are listing is great and keep em comin.

 

Laters,

 

Brian

[GoldNBlack]

A very good read that will hopefully answer the 2.5 vs. 3 on turbo'd cars debate:  

 

http://www.vishnutuning.com/exhaust101.htm

 

 I had to justify my 3" exhuast purchase to myself...

 

 

Steve A.

 

14G-TD05H dumping into Heron's beautiful 3" SS Exhaust.

[Ryan_V]

This car is going to have a 3 inch downpipe that basically curves right out behind the

passenger tire-

[Boosted_One]

Yes, I am going to Ceramikote the exhaust runners in the head itself, the exhaust manifold both inside & out, the turbine side of the turbo both inside & out and the downpipe.  I think this will aide in keeping the heat where I want it.  LOL  I am also aware of flow and increasing flow and velocity.  I am really just looking for little tricks in the build process.  Like, if you take this out or open this up a little, it helps so & so and therefore you get better oiling, or air flow or something.  If you drill out your oil return hole to so & so it helps tons.  You know what I'm talkin about?  Anyways, the things you guys are listing is great and keep em comin.

 

Laters,

 

Brian

 

I've heard some real nasty stories about the cermaic coating lifting off in turbo vehicles. One guy I ran into in the machine shop said he ended up pulling chunks thru his turbo inlet which did a real number to the turbo.

 

I can personally say the cermaic coated pistons I had done, well the coating was burnt off in areas, flaking, etc.

 

Maybe my pistons weren't done right, HPC did them, but I sure can't say anything good about cermaic coating used internally.

 

Look at my pistons in the Engine mods forum. Those were ceramic coated. All burnt off.

 

Just my experiences with it.

[DRQuest]

Ok guys I'm NOT a PRO engine builder but I have worked for a few VERY GREAT ONES and the best tip I can give you is check all your tolerances and keep everything as clean as you can. Port all your runners from the intake(IE the Throttle body all the way to the Exhaust side of the turbo) to flow as much as you feel your setup is going to need and on the intake side you want a swirl for mixture. Exhaust side you want clean clear excapement (polish but not to a chrome like finish, just as smooth as you are able to get it). Weight in the motor is a serious thing the more you remove the better, to a point. Oil drainage is a good thing to work on for this motor also, the better the drainage the more power you will be able to make. Backpressure is also a big issue in this motor so try a vacuum pump in the crankcase or something simular ( I have seen increases in HP numbers just bolting one on a N/A motor for the strip). I don't have proof of all I'm saying for this motor but it is a gas feed deal and I have done many of them for a large variance of driving and racing styles and always use this same proceedure in all that I do and I have always gotten want I expected from all the motors that I put together. Speed is a money thing, how much power you have or want depends on how deep your pockets are!!( NO EXCEPTIONS THERE)  

[Conquest351]

YES, crankcase vacuum pumps work great.  I think I'm gonna jack one off a Z28 or a Cobra.  Both are electric.  There is a place I would like to place it as well.  Hehehe  This is gonna be fun the more I think about it.

 

Anyone else.....?

[DRQuest]

Gains for power can also be had by doing a lot of weight reduction to the crank and rotating assy, big bucks in some cases but not always as such in this motor can get aluminium rods for under $400 and crank can be knife edged and oil holes champered and polished for under $300 . Go to the lightest piston and pin assy you can and you can also gain a few extra HP's by swapping the chain drive to the cam for a belt ( weight reduction, better harmonics ). Grinding the block for weight reduction is a plus if you are not going to drive it daily take it to the limit but not for the DD type ride just do what you have too to clean it up inside to help drainback.Aluminium main caps will aid in weight reduction overall and help with harmonics also and are proven in drag motors daily for strength. Look at the oiling side of the block and drill all the passages 10-20% oversize in the main galleries not the feeds to the cam and main journals and deburr all with a polishing stone as best you can and try to make all turns as smooth as possible and rounded as best you are able. Not a lot of power to be gained there but a big plus for less turbulance in the system (will aid in the gains for power by less turbulance to the pump).Electric pumps for the water and fan drives are worth 2-8 HP depending on what you choose, can call me if you are in question about anything I've stated here have been doing motors for 30 + years for nascar , arca , asa and drag cars around this area. (919)499-0366 Darrell Richardson

[Mark_T]

I was looking at what has been posted sofar and I sawone thing I forgot in doing a bottom end .  Have the main bearing journals line bored if they are off at all.

Have fun

Mark T

[89onaquest]

ok, no no no.

while im saying this, keep these key points in mind.

velocity = speed, as used here, speed of the exhaust gas.

diamiter = size, pipe size, drr.

flow = absolute maximum it will flow.

 

when you take a three inch pipe, and compare it to a 2.5" pipe, we can all se how much more it will flow, what you dont see, is how much less velocity that jump makes. velocity is what makes your turbo spool faster. ---your all gonna disagree with this point--- when you take a stock turbo and head, and port the livin crap out of it, you get more lag. sure you get more flow on the top, and thats why we do it. I had no lag what so ever on my 87. untill i ported the head. sure i got more power, and higher boost, but more lag. it took several 100's more revs to get the same boost. Y? because the same physical amount of exahust gas comeing out was spread over a larger diameter port. it moved SLOWER. the slower moving gas means slower spinning turbo. the same will go with the exhaust. the more velocity you can get with the same amount of air, the faster everything will work. Its a proven fact, on both na cars AND turbo cars. sure you get more flow out of a larger diamiter pipe. but for 90% of us, that jump just doesent help that much. Its cool though, to say "i got a 3-inch mandrel exhaust from the turbo back." -thats what i say. I got a 3" exhaust. But do i need it to flow that same amount of air? no. Im still running a 12a.

Think about how much air our engines use. at 15psi at 6000 rpm we use about 500cfm. (and thats exadurated) you think a two and a half inch pipe cant flow that?

-besides, more velocity at the lower end revs means more tourqe, and thats just the way every single internal combustion engine on the planet works.

 

Dont think you (Mr. pop-zits) can just mosey your way on in here and tell me whats what. Show me your ASE certifications (and yes I, DO have 11 of them) and then ill shut up.

I plan on doing a step up exhaust. 2.5" DP/flex. 4" after go to 2 5/8. 3 ft later go to 2 3/4. about the rear axle go to 3" rest of the way.

Nice steady increase in mass, and keeping the velocity up.

[cudabnu]

You guys are missing something here, sure the analogy of blowing into a fan is true, but that is why the exhaust housings are tapered into a "8cm" opening. porting the area where the exhaust hits the wheel will cause some lag. BUT....after the exhaust passes the wheel, thats it!, Job done! get it out of there as fast as possible! Why do you think the racers just have a dump tube on the exhaust side?

 

just food for thought.

[Dcrasta]

Tip..

 

 Port the exhaust wastegate area behind the flapper. Huge transition there sure to impede flow.  also remove the step (if you are using the stock housing).

 

as far as the 3inch / 2.5 inch debate, everything I read about exhaust sizing is broken into two groups, NA vs Forced Induction. NA, yes you need some backpressure, its all about velocity for cylinder scavinging, thats why alot of NA exhaust use equal length runners, specific sizes for exhaust manifolds and collectors, and crossover points etc.  You rarely find a NA system over 2.5 unless its running huge displacement/rpm.  Forced INduction engines, OTOH, usually have the turbo as the huge restriction, after the turbo (like Chip said earlier), most of the information I have seen recommends the least amount of backpressure possible.  FLow is not about velocity after the turbo, more about volume.  THe perfect exhaust for the turbo has been expressed as a pipe resembling a megaphone to allow the pressure wave to expand quickly in the shortest amount of space possible.  I think a 3 inch exhaust from the turbo back would be the best considering all the work has been done.  ANd its not about the pressure (physical pressure) that is turning the turbo, but rather the heat / gas expansion .  for details go to www.turboclub.com and click on the 'what is a turbo' link.  then reconsider most of what you know ..  

[s.kodai]

whoevewr has the glasspack muffler:

 

GET RID OF THAT P.O.S.  glasspacks are the most restrictive mufflers EVAR!  get a real straight thru muffler, you will notice an immediate difference, especially with a turbo.  i ahve an old hot rodder magazine were they did muffler tests.  glasspacks are almost four times as restrictive as the cheapest real muffler.

 

i got my roommate to dumo his glasspack to a walker ultraflow, just that nothing else.  he picked up almost .3 in the quarter (mostly in the 60 foot times down .2).  and they were all consistent runs.  i mean all runs before and after were within .05 second.  i wish i could be that consistent.

 

glasspacks suck.  loud does not mean powerful.