Gatecrasher

Twin Turbo YB

I don’t pretend to know everything so please don’t burn me at the steak for this as im Genuinely interested to know if anyone has tried to convert a YB to twin turbo before or if it has ever been done?

Is there a reason for no one trying it, is it a bad idea, why would you not do it or is it no possible?

the problem is my cars only running a T34 with .63 housing and the Lag is doing my head in and I also want more power!

I know with a GT28 I can reduce the lag but then the most power im going to be able to get is 400 to 450hp and I know this isn’t going to be enough to keep me happy

On the other hand if say I go for a GT30 or a T4 the Lag is only going to get worse but this will give me the power that I want

Ok i could get a T4 maramed and antiLag but thats not Practical for the road and not all tracks will Allow the noise it will make

Easy option would be to forget Turbo engines and go for a natural aspirated engine but anything that is 500+hp is going to be big and heavy like a V8 or larger and I love Boost anyway

say for E.G. a GT20 56mm, 55trim, 0.53 A/R is rated to 260hp and from the compressor map it looks like it makes it at 1.6 bar and as they are so small there would be hardly any lag and with 2 you could make 500+hp

Why wouldn’t this work why has no one tried it or has it been tried before and it doesn’t work?

thanks

Chip

iTrader: (3)

Two different possibilities here for twin turbo with two turbos the same:

1) Both running at once all the time:
They would only see half the exhaust gas each and would therefore be as laggy as any other 260bhp 1 litre engine, ie as bad as a GT30 in the first place, in fact probably worse due to the fact the pulses of pressure would be so far apart.



2) RX7 style, one gets all exhaust gas to begin with then they share it later on
Its possible to make it work Im positive, but its complicated to do, and bare in mind that in the case of most cossies, they are ran by an L8 more suited to basic engine configurations.

You are looking at custom everything to do this, LOTS of work, so if you pay someone its going to be very dear in labour.

Stavros

Yeah its been done on YBs, and on the whole it works.

It just is so complicated and a pain in the arse to get it all working well, esp as you limited in room, its never taken off.

If you want instant power and cant even deal with T34 style lag but want more power, you either need a stroker kit, standard cams/ports, and a GT30, use nitrous as ALS, or fit a bigger engine.

Well, you could do the twin turbo thing, or even better twincharge it with a supercharger and turbo, but the above options would be fuckloads simpler.

Chip

iTrader: (3)

The answer is nitrous IMHO

Fit a T4 or GT30 so you get the power you want, then just use a sniff of gas to overcome the lag, if the bottle runs out it just means its a bit too laggy again, so youve lost nothing, the cost of the gas is high, but low compared to developing a proper twin turbo setup

Gatecrasher

chip can you Elaborate on 1) as i dont quite understand what you mean why would you get the same amount of lag from a GT30 With 2 GT20's?

Stav have you got any picks/info on the TwinT YB's

Basic fab work would involve

Exhaust manifold, Inlet manifold, Twin intercooler & Exhaust system

i know theres a lot more involved autronic or T6 could manage the Engine managment i wouldnt use L8 Chip my cars on P8 now

Chip

iTrader: (3)

Because the GT30 gets 2 litres of gas, each GT20 ges 1 litre of gas.

So they spool up the same either way.

Gatecrasher

Yeah i thought Nitrous but like you said every time it runs out its the agg of having to go and get it filled up again its ot practical and how cool would it be to have somthing as Unique as a TTYB

If the fab work, under bonnet space and time is the only issue i dont see that as to much of an issue

Chip

iTrader: (3)

Fit 3 bottles, fill them all up once a month, problem solved.

The fab work is the easy bit on the TT setup, the design and mapping are the hard bits.

Gatecrasher

So what your saying is there would be Absolutely no gain in having 2 GT20 over 1 GT30 on a 2 litre YB?

Chip

iTrader: (3)

If they were in parellel and both seeing half the exhaust gas each all the time, yes thats exactly what im saying, in fact IMHO it would be laggier due to the time between exhaust pulses and the fact that the pulses are still big enough that you would need big exhaust housings to not see flow problems.


RX7 stylee, with one i use first then both, would be great, but fuck me thats complicated for designing in your shed at home really TBH and get working perfectly.


The nitrous solution is cheap and easy and is AWESOME, you really need to try it to see what I mean!

Charlie Chalk

iTrader: (1)

Im thinking of nitrous in the new year chip... thing is, what kinda gearbox ( ) stress is there for the ALS style set up?

I hate how laggy my Pulsar is

cossie4i+

iTrader: (15)

AVA done a Twin Turbo YB

Steve.

Chip

iTrader: (3)

I dont think pulsars are very laggy TBH, so you would hate a stage 3 or more YB raddes!

ALS style setup with nitrous puts very little extra strain on the box as ultimately it doesnt increase peak torque or bhp AT ALL, and its the peak stuff that tends to kill boxes (well that and agressive changes, especially on pulsar selector forks!)

Charlie Chalk

iTrader: (1)

I've been told my car maybe laggy due to it being out of tune.. Don't know how true that is mind... But its being setup soon, once the HG is done this week

Good job I dont rag the shit off it then...as such...

Chip

iTrader: (3)

Id be inclined to beleive them, especially check your cam timing.

Gatecrasher

It wouldnt be at home in my Shed mate i would sub the work out, I.E. get proalloy on the intercooler rad side of things, someone like primery design for the exhaust manifold, Hayward and scott for the Exhaust, Stu at MSD to map it on T6 ect ect

how much is a cheap Nitros setup for the lag on my current setup and how safe is it?

Charlie Chalk

iTrader: (1)

Ah ok , Its being done this week after HG

Gatecrasher

Is that Dumped's compound engine you are on about?

Gatecrasher

What turbo is on your pulsa radders?

My car is going to harveys in the morning to be setup and have the antilag, air injectors and Greys fitted so maybe it might not feel as laggy when i get it back

Chip

iTrader: (3)

Thats all the simple bits, the expensive bit is the dyno time in getting the system to work with feeding one turbo then the other etc.

About 80 vacuum pipes and loads of "gubbins" on an RX7 to do it well.

Thing is, even if you got lucky with that and got it all right first time, its still a 10K+ project, you can buy an LS7 for less than that and it weighs the same, makes 500bhp and has NO lag.

600 quid or so, and safer than being on big boost is!

Charlie Chalk

iTrader: (1)

T28 .86

Gatecrasher

Whaaaaaaat! did i see you say your after a T34 the other day PML!!!

When is your turbo on full chat then? mine at about 3500rpm at the mo

cossie4i+

iTrader: (15)

Good luck

Hope you are happier with it when you get it back.

Do you want to try this new Dastek RR in Canterbury ?, keep thinking of taking my car for a power run.

Steve.

Charlie Chalk

iTrader: (1)

T34 .48 will do me....

Not sure tbh when its on full chat, havent driven it for ages now, so forgotten

Gatecrasher

what typ of RR is it mate any links to a website or anything? ile have a go with you if its a gooden

Radders how can you forget lol T34.48 shouldnt be to bad from what i have read, you only got a t28 at the mo so who knows saying that .86 is that the Exhaust housing that sounds a bit big for a T28 no? mines a .63 on a T34 so why so big?

cossie4i+

iTrader: (15)

Its a Dastek RR, got a good fan setup as well, the place is called Rapid Chariots, its on the A28 at Chartham

Steve.

buzznwood

Turbo technics did a twin turbo YB years ago that worked quite well, wasn't huge power from what I remember, pretty sure turbosystems had some input into it.

If you want to run a GT30 then you should think about using a divided housing (twin scroll) GT30, as this will give you all the benefits of a twin turbo setup without the hassles of having to find room for two turbos and all the plumbing that goes with them. You will of course need a new manifold by getting a 4-2 manifold made up shouldn't be that hard.

Gatecrasher

Steve just had a quick look at Dastek RR, do you know if they are Accurate, i mean i would rather take a drive up the road a bit to go on a Dyno Dynamics RR as they seem to be the most accurate, or read the lowest

Charlie Chalk

iTrader: (1)

Taken off the GTiR owners...

Fastmaul

Why not just get higher compression pistons? I don't know why I read so much about lag here, maybe the engine isn't set up correctly?

cossie4i+

iTrader: (15)

Im not sure how accurate it is, but the last time i had my car on a RR at was a DD one, not done anything to my car except uprate the fuel pump wiring and removed the caps off the injectors.

So if i get loads more power then no it ain't accurate lol

Steve.

Gatecrasher

Im up for it then here is there site http://www.rapidchariots.co.uk/dyno.htm looks ok how much is it do you know?

Chip you care to comment? looks to me radders like hybrid T3 witha big exhaust housing take no notice of me tho mate i just come to ask questions

Gatecrasher

you have totaly lost me with the Twin Scroll, how do you divide the turbo housing

Higher Compresion will not iliminate Lag will it, and above i did say my cars going to be setup tomorrow as is radders, i dont think this will stop the lag tho might help a bit but a T34.63 makes full boost at 3500Rpm and thats that i think?

Benni

Can you not just get ALS?

dojj

iTrader: (3)

tt did them for £6k way way back
i don't think they ever sold a kit other than the one they made for the demo
it had a k gate in the exhaust that would let you spin up the smaller turbo first and then, once it was sinning happily, they would bleed off a bit of boost form it to feed the second bigger turbo so when the gate opened fully, the other turbo was already on song
so effectivly you had one small turbo doing the lower end work which was good for say upto 4000 rpm, but seeing as it was "feeding" boost to the bigger turbo, the bigger turbo was already getting spun up to be unleashed when the smaller turbo ran out of puff

don't know the exact plumbing but i'm sure someone in teh back issues section of pf or ff will be able to have a rumage around and find it

i think it's going back a good few years though, about the same time as the 2.4 pe conversions were about

cossie4i+

iTrader: (15)

Just looked on the site and its £40+vat, which includes AFR & Boost graphs also power and torque @ wheels and flywheel.

Steve.

Charlie Chalk

iTrader: (1)

He is getting ALS today if you read Benni But its not suited for everyday road use tbh

Chip

iTrader: (3)

Nitrous as antilag can be used happily on a daily driver.

SapphyMike

any recommendation on jet sizes / set time for the nitrous to stay on for?

Chip

iTrader: (3)

Its engine dependant.

On a L8 YB though, with the ability to retard ignition so easily, id be looking for 100bhp or bigger jets, but on a progressive buildup for an ideal solution, on a VERY sharp rise time though, so start at 40bhp and build to 100bhp+ in 2 seconds or less, then put a boost switch on to cut the nitrous off again at 20psi or whatever is appropriate, used like that for only a couple of seconds at a time, a bottle lasts a long time (like 100 instances of WOT from an 11lb bottle)

It really does make an immense difference to how they drive.

If going for a fix hit, 50bhp gets my vote.