Twin Turbo Thread
 

Ok, ive decided a couple nights ago that I wanna twin turbo my truck. I know a thing or two about turbos and im gonna peice one together. im gonna use a couple mitsubishi 14b turbos because theyre small to work with, ill find a good size intercooler core with custom piping, probably a turboXS RFL blow off valve, ill need custom exhaust manifolds and downpipes(unless my shop can fabricate something out of the jba headers), boost controller, ill have to do something about tuning any help with that would be great, just have an oil return welded onto my oil pan, 6 injectors-not really sure what ill need for those either, and some misc vacuum lines. what is everyones thought on this?

I think it's going to be a lot of work, but cool as hell when you get it finished. Not many people have turboed Rangers, let alone TWIN turboed!

turbos suck on v6s. you can do better with a big turbo and the best with a supercharger. they may be more expensive but you get what you pay for.

i know itll be a lot of work, but how does a twin turbo suck on V6? 300zx, 3000gt, 350Z/G35? those dont suck, and ive never really liked superchargers, you can only get as much as your engine gives.

Ha, tell that too the 3.0L Inline 6 Twin Turbo Supra owners, who could wax anyone on this forum stock..lol

Leo, he said turbos suck on v6's, not inline 6's :smirk:

It won't matter if it's a v6 or v8, a v8 can make over 1000hp off 1 turbo, so I could see a v6 making 600-800hp np with the internals to back it up of course. Turboed 4 cylinders can beat vipers, I've seen it happen. Turbos are the **** now, I'd much rather have a turbo over a SC. If you match the turbo up just right, you'll have 0 turbo lag and you have roast a SC off the line.

you will see much more performance from a single turbo setup for our trucks. Do you know what the purpose of a twin turbo setup is?

it all comes down to

Efficiency, Power

All turbochargers present compromises between flow capacity and turbo lag. The larger the turbo, the slower it is to spool, but the more air it can flow when up to speed. The FD's units were sized for maximum response while meeting the flow requirements of the engine at the targeted power level. Each compressor has an area of greatest efficiency (adiabatic), in which it can compress/flow a given volume of air per unit time without introducing excessive heat in the process. This is defined graphically by a compressor map, and is primarily a function of compressor design, size, and rotation speed. Increase flow to obtain more power on the FD by adding intake, exhaust, intercooler, etc.and you will rapidly find yourself outside the stock turbocharger's efficiency sweetspot, since the compressor must spin faster to maintain the same intake pressure. The main detriment in the 11-13 psi range is that the compressor outlet temps become extremely hot, on the order of 300F, which places additional thermal stress on the engine, and may increase detonation risk. Also, in sequential twin-turbo cars, the secondary unit is accelerated to a high speed in a closed circuit chamber (surge) to prevent a drop in compressor speed and flow at the switchover point when the compressor comes under load, which would cause a dip in power and torque (the famous dip we all notice in the dyno plots). This power dip, already slightly noticeable in stock cars, becomes much worse in modded cars, since the turbo is already operating at its pre-spin speed just to maintain a given level of boost, and becomes extremely resistant to overspeeding.

Over 14 psi on sequential twin cars with fully open intake and exhaust, the stock turbos actually cause a restriction in the intake path which limit the effective power you can make. Can you upgrade to larger compressor wheels? Sure, but shaft failures often accompany this mod, because the stock shaft was not sized for that weight wheel. You can also clip the turbine wheels for better flow at high speed, but low speed response may be impacted. The switchover problem does not go away.

So, the guys who want BIG power (360 RWHP +) go to a single, large turbo. And they throw in a whole new fuel system just for kicks (also happens to help keep the engine alive). What they gain in power, they lose in response. Drag racers don't care about this because they can pre-load the turbo off the line, use NOS, or some combination of the two, and benefit from tremendous increases in top-end power. Road racers (especially those who drive tight courses) do care, because the car is either way too fast or way too slow (just like the old Porsche 930 Turbos). For them, nothing beats the response of the stock sequential twins.

In terms of reliability, the stock system is extremely complex, not very durable, and most people have no clue how to troubleshoot it. The nest of vacuum hoses and solenoids has driven many an at-home mechanic to the brink of suicide. Even when it does work, it is not entirely consistent in its operation, to put it politely. So you may be left wondering where your second turbo is as you watch Jim's Supra blow past you (probably would anyway). Bad as that is, increasing boost on the sequential system seems to present problems for piggyback boost controllers which are totally beyond the scope of this post (to the extent the post is not already beyond its own scope). The PFS-PMC seems finally to have overcome the majority of these problems but it has taken six years! The solution to this melodrama for some, is to go single turbo: one wastegate, one boost pattern, no vacuum nest, no solenoids, theoretically easy fuel map etc. So say the single turbo guys. And their results at the strip corroborate this view.

cliffnotes?

An sohc running ' twin ' turbo's. I'd like to see it happen. A lot of people bosted how their pants were all wett when they heard of whipple making superchargers, all of 2 people bought them ( lol! ).

I looked into a turbo setup for a while and decided a centrifigual setup was much better for street applications. Leave turbos for inline engines and rice.

I wouldn't even aproach doing a turbo without looking at the bottom end of your engine. Its durable, but not bulletproof.

Good luck.
D.

well like i said, im using one of the smallest turbos on the market, im not trying to make a monstrous 8 second truck. Ive talked to a few guys and what i can gather is the block will hold up to what im gonna give to it, 8-10 lbs with some ARP studs and i should be fine. from what ive found its never been done before, been done to some V6 camaros and such, but not a v6 ranger. theres a first time for everything. Ive always been a turbo guy, i know how efficient SC's can be, but the limits are endless on a turbo setup.

Next to a NOS purge cloud with a light, nothing is cooler than the "Pffffft" sound from a BOV. And them boys with the rice can kill people with turbos, ahh like the famous 98 Civic that killed a Viper... that was funny.

I'd suggest talking to Andy and reading up here: http://www.members.aol.com/andylittleton/tma.htm and seeing if he can fab you up something. For v6 Mustangs running 5lbs+ of boost we need 42lb injectors and 300lph Fuel Pumps. For tuning talk to Justin at http://www.velocitymustangperformance.com/ I'm sure he can custom tune a turbo truck if you were to give him a list of your mods gearing, etc...

i found out its not possible anymore, so im gonna have to go single turbo. ive got someone to fab up my manifold and downpipe, and ive got a turbo to use, and ill have to come up with some 30lb injectors, and the fuel pump should work fine. im only gonna have about 8-10 lbs of boost

how much will this run u?

and u're gonna use NAWS?!? haha j/w

bah, i bet you blow the engine with 5lbs of boost...

The engine will not hold.. Hell, a built 3.0 couldnt handle nitrous..I've seen it... much less the forced induction of a turbo..

He should drop in a 5.0 and use that as a base or even an 00+ V6 would be better.

I think the Whipple kit boost is 5 or 5.5 psi. I think with a turbo/intercooled setup you could boost a little more than that.. Biggest problem is not fabbing up a bunch of pipe, but more the fuel management...

Some misc. comments :

"The engine will not hold.. Hell, a built 3.0 couldnt handle nitrous..I've seen it... much less the forced induction of a turbo.."

Leo, you must remember, The SOHC's oil pan is a 2 piece design, it acts as a main support system for the bottom of the engine. My procharger was pushing 7lbs before I had my accident, and it was a very *conservative* 7lbs.

"i found out its not possible anymore, so im gonna have to go single turbo. ive got someone to fab up my manifold and downpipe"

Thundakat85, I think you mean in plural fashon.. ' manifolds ' , endless your running a 4 banger/inline engine.

"ill have to come up with some 30lb injectors, and the fuel pump should work fine"

Methinks you'll be using ( at minimum ) 36# injectors and putting either an svt focus or 155lph pump in or else you will starve your mill, mate.

I would REALLY love to see this ( being sincere ) as there are a LOT of people who ' Dream '. MANY people were crying and touting how ' whipple will save us all! '. I know of 2 trucks with them. Doug904 ( he's sponsored by them ) and another guy ( justin from chicago ) whom traded his truck in for a mustang ( he's still selling the whipple kit I believe ) .

Personally, I only know of 1 ranger ( that I have had the glorious operatunity of throwing down with ) that has ever had a turbo on it.. It had a 4 banger and was quite a zippy little thing.

Even with one hell of a custom exhaust and having acess to the greatest fab shop in the world.. practacality and economics for such a thing don't make sence.

Your best bet is a roots setup or a bottle. For longevity and cost of ownership ( I have to re-plumb an innercooler, replace the headunit and fab all new plumbing ) after either you or some nucklehead damages your setup... exotic is quite expensive, and it will be a while before I have the bennies to put my setup back together.

Someone mentioned -- > "He should drop in a 5.0 and use that as a base or even an 00+ V6 would be better.", those are some WISE words. A built 302 and a fabbed swap kit ( your going to do exhaust anyway ) will yield you much greater torque levels then your tiny ( or huge ) turbo could even begin to dream of for the same cost ( probably less ).

A good old pushrod 5.0 from summit race equipment and an L&L swap kit would run the same money, produce ( probably ) more power AND still have the option for a blower, turbo ( theres already kits with everything worked out ) , Nitrous and even DUAL power adders.

What your speaking of ( turbo setup ) will look like a pipedream by most. Weather it is or not is for you to decide.. but it just doesn't seem logical nor practical. *I* like to be different . This is why I hope you DO suceed in going through with this.

D.

D, Ive seen like 5-6 guys on GE with the whipple already.

seems like i was on a site that had a 4.0 running twin turbos but i cant remember where

it was this company that made one,

http://www.idaautomotive.com/turbo.html

cant find the info on the ranger but it ran a 13.41 1/4 mile

well, ive talked to a couple best of the best for guys, and it seems everyone has their different opinion. i only need 1 manifold if im doing a single turbo setup, like the Grand Nationals. i never said i was running nitrous, ill only do that on a fully built motor. the stock fuel pump will hold up to what i need, and i dont need 36lb injectors.

Again, D, its a 3.0, not a 4.0 ...

How do you only need ONE manifold on a motor with TWO banks of cylinders? Maybe you worded it wrong, or you don't know anything. Please clarify.

Also, what are you going to do about fuel management? FMU?