Turbo combinations for my 1GZ

[Kagetsu]

I have to admit, supercharging is looking very sexual at the moment, but Turbo's sound so great with their BOV's... also, I want flutter. ^_^

EDIT: Did notice your post, and was thinking on it. ^_^' Thanks for that though... I'll hopefully have an idea this weekend on the viability of it. Will be interesting to see how much wall thickness it can spare.

What about sleeving piston chambers?

[Mr Ed]

Turbo's sound so great with their BOV's... also, I want flutter. ^_^

Sounds like you should have bought an SR20. Now sell the 1GZ to Norbie to put in his Celica!

[Norbie]

Overboring the block may not be a straightforward process since it's an alloy block. Not sure on the 1GZ (who is) but other alloy engines like the LS1 can't be overbored at all because of some special treatment used on the cylinder walls.

Maybe the 1UZ guys can comment on this - it's a good bet the 1GZ block has similar construction?

[benjamin]

Nothing makes other people go "What Tha F**k" than a superfast car, screaming (or whining) past and NOT farting a crap load of air through a BOV when the gears are changed.

Whipple gets my vote.

[Kagetsu]

That's true.

[MS-75]

550rwkw will be excellent mate-and silky smooth with 12cyls.

It'll probably be a bore&sleeve job to increase capacity-but ultimately, you're going to need strip the entire engine and see what it's like inside to know what's possible.

I'd also get the crank fully prepped as well-you don't want it breaking as god knows where you'd get another one.

It'll sound awesome-supercharger or turbo.

[Bored?]

OldCorollas: Compound charging in general is very cool, but it's more suitable when you need a very high pressure ratio compared to the peak flow rate. Since we already established that the required boost for 1MW was in the efficient range for a single stage turbo, it doesn't make sense in this application. Where it does make sense is in smaller capacity engines that require very high boost to achieve the required airflow.

As for 550kw, Personally I'd shoot just a little bit higher since the costs in building the engine won't be much different anyway (you're looking at the same engine mods anyway, and speccing slightly bigger turbos and slightly lower CR won't cost significantly more).

[Andrew162]

Hmmm, I was wondering how a twin-turb'd V12 would sound in comparison to a Whipple/supercharger on it. I think the very fact that a V12 in a Supra would be enough to blow almost any car enthusiast's preverbial doors orf, but seriously for the power output you seek (realistically) and linear power delivery to a 5L V12.... turbo's are a great option, but I'm thinking a supercharger instead.

Even seeing this thing completed will be a mammoth task and uber-bucks spent... but WTF-factor FTW.

[RONA]

Overboring the block may not be a straightforward process since it's an alloy block. Not sure on the 1GZ (who is) but other alloy engines like the LS1 can't be overbored at all because of some special treatment used on the cylinder walls.

Maybe the 1UZ guys can comment on this - it's a good bet the 1GZ block has similar construction?

http://www.popularhotrodding.com/eng...05em_boredls1/

what you talking about Willis

[ed]

1uz is sleeved, and can hack about a .040" overbore

i think youre thinking about the bimmer v12's (m70 etc) with their non sleeved raw silica alloy blocks that are chemically honed - and cannot be mechanically rehoned

[Norbie]

i think youre thinking about the bimmer v12's (m70 etc) with their non sleeved raw silica alloy blocks that are chemically honed - and cannot be mechanically rehoned

Could be. I read about it somewhere, thought it was the LS1 but my memory ain't what it used to be.

[oldcorollas]

OldCorollas: Compound charging in general is very cool, but it's more suitable when you need a very high pressure ratio compared to the peak flow rate. Since we already established that the required boost for 1MW was in the efficient range for a single stage turbo, it doesn't make sense in this application. Where it does make sense is in smaller capacity engines that require very high boost to achieve the required airflow.

As for 550kw, Personally I'd shoot just a little bit higher since the costs in building the engine won't be much different anyway (you're looking at the same engine mods anyway, and speccing slightly bigger turbos and slightly lower CR won't cost significantly more).

yar i was just thinking of having the belt turbine a semi removable item, so it gives the extra boost for the dyno runs, thru already capable turbos, but removing the need for such large turbs otherwise (by increasing input pressure.. or does that not reduce surge (by reducing pressure ratio)

[6BOOST]

yar i was just thinking of having the belt turbine a semi removable item, so it gives the extra boost for the dyno runs, thru already capable turbos, but removing the need for such large turbs otherwise (by increasing input pressure.. or does that not reduce surge (by reducing pressure ratio)

You will still need turbo compressors capable of the final power output whther they are run with a blower or not, boost pressure is a function of shaft speed as is airflow output, so if the blower is moving enough air to make 1000rwhp, then it has to come through the turbochargers, hence, their shaft speed and comp flow will need to be directly proportional to desired hp output. The only benifit I can see to twin charging would be faster spool and higher PR, but I've yet to see any evidence or back to back testing to suppor the fact that they actually do decrease spool, I mean I can understand the theory, but it just doesn't seems to actually work.

6BOOST

[oldcorollas]

oh ok.. i was thinking abotu the turbos pressure ratio, and increasing intake pressure would increase outlet pressure... but i am not sure how the physical mass of the air affects it vs the volume....
now i'm totally confused

[Hen]

6BOOST I don't agree.

Lets say a certain turbo in a normal setup (1bar absolute pressure at the inlet) can flow 600hp (pushes X cubic metres from inlet to outlet per second) under certain conditions.

Now keep all conditions the same but whack another turbo or supercharger in front of it and feed it with 1bar of boost. The turbo inlet is now seeing 2bar absolute, as opposed to 1bar in the situation above.

If the turbo pushes X cubic metres per second from inlet to outlet under normal conditions, it will still push that same volume now, but since the inlet air is twice as dense, twice as much air will be moved. So now it should be capable of supporting 1200hp.

Basically the pressure ratio and flow VOLUME remain the same in both situations, just the flow MASS will double if the turbo inlet is fed 1bar of boost.

This assumes all other things are equal, which they wont be precisely, but the theory should hold.

Hen