Twin turbo,s dump valves ?

Twin turbo,s dump valves ?

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mighty kitten

Original Poster:

431 posts

132 months

Sunday 17th April 2016
quotequote all
The water meth jet is after the ecu ait so it will see what's actually happening . ive set the protection at 70c to bring in the soft rev limiter but it's got nowhere near yet and the meth is triggered at 50c with some hysteresis so I doubt it's sprayed yet .

stevieturbo

17,229 posts

246 months

Sunday 17th April 2016
quotequote all
If you've no intercooler, I'd be spraying a bit more, bring it on at say 40-50degC

70degC is still pretty warm, especially considering the high compression. I wouldnt want my air temps anywhere near that with such high CR unless you were using very good fuel.

mighty kitten

Original Poster:

431 posts

132 months

Sunday 17th April 2016
quotequote all
Pulled the trigger temp down to 50 c and Tps to 40% as I'm not really needing much to spool it to 7 psi ,
Blowers and manifolds off today to give them a good rub on a machined block as they're both chuffing a little now they've been heat cycled for a few weeks

Tony427

2,873 posts

232 months

Monday 18th April 2016
quotequote all
stevieturbo said:
Tony427 said:
Can I just ask what Turbos you are using?

Once through IVA I intended to turbo my Lexus engined Cobra but am now undecided between twin or single Turbo.

What would you advise?

Use would be only for mild hooning, too frightened of running out of talent to track the thing.

Cheers,

Tony
How much power ? and are you after new, used, cheap as possible ?

With a 4.0....and so many modern turbo petrol cars out there, there will be plenty of capable second hand turbos out there, although a lot of OEM stuff have odd flanges and fitments

On the cheap, Subaru TD04's are great fast spooling little units, or almost anything starting GT28 would be a decent bet. Or some of the KKK's fitted to either 1.8t or the 2.0 VAG group engines.
I'm looking for something that I can begin with on standard ecu ( about 6 to 8 psi) and which I can upgrade with standalone Ecu when I have to replace the standard auto box and thus can lose the autobox control function within the OEM ecu.

I had planned on going dowm the twin GT28 route but time has moved on and I now hear tales that big singles are as responsive these days as twins, especially as I already have 4 litres so immediate spool response may not be paramount.

A big single would be easier for underbonnet packaging I have a nice space available next to the NS exhaust manifold and can put in a crossover pipe under the sump.

Are larger singles as responsive as twins these days? ( That souunds like a question for a dating site?)

Would like to get started as cheaply as possible ( secondhand/ breakers) and frankly don't trust the new Chinese stuff on internet auction sites. Is this justified or am I tarring every chinese turbo with the same brush?

Cheers,

Tony

stevieturbo

17,229 posts

246 months

Monday 18th April 2016
quotequote all
Tony427 said:
I'm looking for something that I can begin with on standard ecu ( about 6 to 8 psi) and which I can upgrade with standalone Ecu when I have to replace the standard auto box and thus can lose the autobox control function within the OEM ecu.

I had planned on going dowm the twin GT28 route but time has moved on and I now hear tales that big singles are as responsive these days as twins, especially as I already have 4 litres so immediate spool response may not be paramount.

A big single would be easier for underbonnet packaging I have a nice space available next to the NS exhaust manifold and can put in a crossover pipe under the sump.

Are larger singles as responsive as twins these days? ( That souunds like a question for a dating site?)

Would like to get started as cheaply as possible ( secondhand/ breakers) and frankly don't trust the new Chinese stuff on internet auction sites. Is this justified or am I tarring every chinese turbo with the same brush?

Cheers,

Tony








But really, if a single is easier to package, just go for a single, dont get hung up on it either way. Sized right is sized right, you can get it right or wrong whether it's twins or a single.

Only think about the large single....is there may be slightly fewer options knocking about on the used market. That said if it's lowish boost/power, then some of the GT35/GT40ish type sizes would probably be quite fine.

If you can re-use factory exhaust manifolds and just make adaptor pipes, small diameter to the turbo, even easier.

mighty kitten

Original Poster:

431 posts

132 months

Monday 18th April 2016
quotequote all
unless you have some sort of interface to see what the Lexus ecu is doing its going to be a shot in the dark getting it tuned safely and why I went with aftermarket although very basic ecu . Just getting rid of the std manifolds will net 30+ hp on the 1 uzfe .
Starting my build now I doubt I would bother with turbos as the car is light enough and the torque available is always enough without any boost to scoot along on public roads ,

Boosted LS1

21,167 posts

259 months

Monday 18th April 2016
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Saabs have T2 and T3 flanges depending on the model. Those turbo's are readily available and good for almost 300 bhp if you get something from an aero.

mighty kitten

Original Poster:

431 posts

132 months

Sunday 1st May 2016
quotequote all
Just to wrap this up I took the car over to Bailey performance on Saturday and before adding the meth /water we got 350/380 lb ft at 8 psi and 14 deg advance all in . Meth spray didn't add any power neither did a bit more ignition so the only way up is boost but it's more than enough for now .