Is there anyone running a external wastegate on there cosworth??

im looking to do this on my mk2 escort rs2000 cosworth build

need any info and pic or someone to help me do it?

 

hi mate, what sort of power are you looking for,

this gives us a starting point

 

i have a t3 turbo and it going to be on grey injectors looking for 350 to 400bhp

 

well firstly, you arnt going to get 400hp on a t3

you may just push it on a t34

secondly, there isnt any point in going external wastegate in my honest opinion.

your better sticking with your interneal wastegate and actuator. you can get good enough boost control with a set of air injectors

really, when your going for 500 + bhp then you would start thinking about a external wastegate setup, but like i say to be honest there isnt any point in going external

jim

 

your going to need a minimum of a t34.63 to get near 400hp, and as jimbo said external wastegates are not need at this power level

 

so why would all the world cars use external then Jimbo ?

its not about the hp always

 

in awsner to your question im not sure, i would guess to releive the system of any restrictions, and probably reliability ?

as for my defence, with a yb and in my (little) experience there just isnt a need for them untill you cannot keep a turbo under control with the internal wastegate set up (im talking about turbo's like t4's, you get boost creep)

also the cost invoved in the external wastgate setup, were talking about a road car here i guess, so if its not needed then why bother ?


just my opinion

so, would you use a external wastegate for 400hp ??

 

depends on how much air volume your thinking of moveing and at what rev range.

 

MarkK, why do you think the world cars use them?

I would imagine its more to do with controlling the boost to be low enough on antilag or similar than for out and out power, im with jimbo that a normal T3 on a road car works perfectly well on an internal setup and doesnt need an external one, its just a load of expense for very little gain surely?

 

chip, when using ALS, you dontuse boost control to keep control of the power output, and no again, out and out power is not the issue on world car at all with just over 300hp now is it !

 

Yes and no mate, out and out power is the aim to a certain extent with the world cars as with most cars in motorsport, obviously they are hindered in that quest by the restrictor but they will try and get every single last HP they can with that in place.

 

400hp needs X amount of air,

a small turbo can move X amount of air at high boost or a big turbo can move X amount at low boost, you still have to move the same amount of air for 400hp,

typical yb revs, 7-7.5k revs

jim

 

I agree with the yes and no bits ! but the rules are the rules, so restricted it is, so large volumes of air at low revs is the order of the day, crammed into a low revving engine where VE is not at its best, is part of the reason external boost control is used, as the internal systems thus become a problem.

theoretically very true Jimbo !

without trying to detour from the OP's thread, you can still force and engine to consume the air at differant paces - i.e differing rev ranges spec dependant, to the extreme where the internal gate cannot cope. e.g YB and T4 - im sure you know the score now pal !!

 

This seems like a very good technical thread so far guys. Please keep going

 

Good info Mark, always interesting to read about the restricted cars, although I often feel that its fairly irrelevant a lot of the time to road tuning where you dont have that one single factor so massively dominating the performance characteristics, personally I love turbo engines that just rev and rev, my nova feels awesome at 8Krpm with nearly 2 bar of boost up it, but in a totally different way to when ive been in rally cars with a restrictor where its all over by about 5K!

 

go external,they are used because of there quality,and accuracy(when set right on controller)thats why the rs200,audi s2,bently used them years ago,actuators are so hit and miss (old hat).for example -31 so strong that you get the boost delivered in a big thump.people who cant afford them or dont know how to use them slate them,at least you can run big boost and control where you want the power to come in.hope that helps,oh who do you come highly recommended by ?i just constantly see your comments being corrected

 

Just some bloke called Mike, its only a joke mate.

With regards to the rest of your comments, on a T3 on a YB personally I just want as much boost as it can manage all the time really, they are so piss weak anyway im not bothered much about delivery, but on my Nova which runs a GT35 Im on an external gate and I always recomend them to anyone on a bigger turbo, so dont go getting the wrong end of the stick just from me saying I dont think its worth the hassle and expense on a T3, im not saying that internal is better than external, it isnt, just external doesnt offer enough benefit on a T3 to justify the hassle thats all. I agree its a better solution, and hence that is why people like Audi use it, but retro fitting it to a YB is a ballache for very little gain!
Its rare that my comments get corrected, but they sometimes get mistakenly read and then someone corrects what they think I said but didnt, like you just did there.

 

when ive compared the way the power is delivered on one of my restricted cars to one of non restricted, I always prefer the low donw rush, and im happy to shift at 6-7krevs rather than ringing its neck to 20,00000 rpm.
just two differing choices of the same product i think.

 

Your car with the restrictor removed would still have the low down rush though, just would gain a bit up top.

 

they actually gain alot at the top end, i remember having to put some 30-40% more fuel in on a test we did some time back of the same car with and without restrictor, but there was a trade of as to when the engine made boost compared to the restrictor being in place by a good almost 1000rpm iirc.

 

Ive always wanted to try an inlet tract that can change in diameter and length, I have a basic design in my head that I think would work, just never had a chance to try and make it, would be interesting to try and get the best of both worlds.
Surprised to hear it was as much as 1Krpm though.

 

IMO you want boost to kick in from as low in the rev range as possible,and deliver boost to the top of the range.
absolutely no point in waiting to 4k for boost to get 2.5-3ks worth of boost that really gives fuck all in the way of actual speed.
surely increased power throughout the whole rev reange would thus increase the speed the car travels at??

 

Jamie, of course that is what you want mate, not going to happen on a T3 though, it will be dead long before the rev limiter.

 

probably best to go for a T34 then??

 

Yes, although it will spool later in the rev range then.

 

how bout a GT3076R with all the extras and a blitz dsbc-r dual solenoid boost controller to get the boost in earlier??

 

No amount of boost control can do anything other than keep the wastegate shut, so cant lower the rpm of the engine for the boost threshold of the turbo.
GT3071 IMHO is a very good choice on a YB though, good power for a decent chunk of the rev range, still a compromise though like any turbo

 

fair enough m8.just wondering though why some people bang on about electronic boost controllers bringin in boost earlier?is it just a load of bollocks,cuz some of them are well deer.?
dont know much about cosworth engines as own a rs turbo however i know you want to use the smallest turbo you can get away with lol.
I want to fit a T25BB to my 1,6cvh eventually

 

The best any eletronic boost control can achieve in terms of spool, is the equivalent of pulling the acuator pipe off basically mate, you wont get it to spool any quicker than that.

 

escort WRC cars dont use external wastegates!
i believe the reason why they are used alot in motorsport is that you then have the option of designing a smooth path for the waste gasses! in doing so, you can gain a slight reduction on TIP

 

This bloke CLEARLY wants one so he can boast down the pub!

'external wastegate innit bruv.... sniff'


and it will look dam cool on a Mk2 Cossie

and interesting technical discussion as well

Complete waste of time and money for 400bhp in my opinion though!

 

Everyone was thinking it, but trust you to be the one to say it

 

Have you seen the size of the turbine housing on a wrc car? They are tiny. The reason they use an external gate is that at full chat alot of the gases will be using that route and any effeciencies in flow they can gain will be worth while.

 

That makes sense Doug
Totally different animal to their road going cousins in so many ways!

 

toally different beast to a unrestricted road car!

 

'DIDNT' past tense

 

Why not ask your tuner at what level he thinks an external wastegate is required, in my case think that was at 600bhp. Guess what it performed perfectly at horsepower levels below that so he was right, well that is his job.
Ask on here & you will get Black is white answers from people, who with no disrespect love an arguement. Lee is the nearest answer so far .

 

when spending £12000 on building a mk2 escort shell and building a cosworth to go into it

not knowing anything about cosworths or turbos i need help

spending money on making it right is the first thing.

now going t34/48 360 thrust
grey injectors. 3map bar sensor.
swiddish plenium.
using a brand new 4x4cosworth engine just out of the box

so spending money on the right bits is in portent to me

so if it means fitting the manifold and external wastegate now even if its not needed and then add more power later this most be the best way

thanks for the help even if it did move away from what i asked or should i say THANKS BRUV (i fxxking hate that)

ps been offered a manifold with wastegate fitted

and they are also on ebay new for £200 so not lots of money

 

i be a chav next when i ask whats the best dv to fit lol