[Mk2] [Turbo] Starting build

[bobhatton]

Did I do somthing wrong in my last post for it to be deleted?

[toxo]

Got no record of a post being deleted in the moderators forum

[bobhatton]

Got no record of a post being deleted in the moderators forum

Oh thats strange, where did that go then

[kennym]

Ha i can see it now Bob

" where the hell did this extra thrust washer come from?"

[bobhatton]

Got all the parts from Racerx but not going to have the time to trial fit this weekend.

[Century Motorsport]

Are you using the std oil pump and just using the external pump as a scavenge Bob?

[bobhatton]

Are you using the std oil pump and just using the external pump as a scavenge Bob?

No, two stage suction from the sump but one return to the tank, and one pressure

[Century Motorsport]

Very nice indeed

[bobhatton]

Very nice indeed

Well I hope it will be in the end, only a year late so far

[Magic Beans]

I guess you're aiming to have it ready for the start of the season next year now?

[Century Motorsport]

Very nice indeed

Well I hope it will be in the end, only a year late so far

Work by the 'perfection can't be rushed' motto and you'll be fine

[bobhatton]

I guess you're aiming to have it ready for the start of the season next year now?

That is the aim but with Steve changing his ECU, manifold suspension it’s not just my car I have to concentrate on.

I also keep coming up with new ideas, like the new inlet manifold with individual throttle bodys.

As Nathan says to do it right takes time and at my age I only have one chance to get it right

[Magic Beans]

Completely agree. Do it once do it right

Intrigued by the manifold idea And if you do decide to sell your existing mani I'd be interested in it

[ashley]

What is the theory behind such long runners between the ports and the turbine housing? I can't get my head round why this would be a good thing...I understand wanting to try to equalise the runner length to match pulses into the housing, but surely longer runners mean more exhaust heat is lost in the manifold before hitting the turbine?

Not doubting the design, I've seen Jeff's dyno graphs...just trying to understand the theory!

[bobhatton]

I am sure you will know the answer to this so I will just point you in the right direction and see what you come up with.

So forget this is a turbo engine, now how does the manifold look?

[ashley]

Ignoring it's a turbo, it's a 4 into 1 exhaust manifold- which you'd normally expect to yield better for top end power at the expense of mid range torque, and the header lengths would be tuned to obtain peak power at a targeted rpm.

So I'm guessing you are taking advantage of the scavenging effect to increase peak gas flow into the turbine at the top end of the rpm range, and hence increase peak hp of the engine...which makes perfect sense if you're planning to run a massive turbo on a two point something litre engine where peak performance will always be at the top end of the rpm range.

I'm still a bit confused over the whole heat thing though, I thought the key to big power was maximising heat input to the turbine...so you'll need to do everything you can to keep as much heat in the manifold as possible...ceramic coating and heat wrapping?

[bobhatton]

Ignoring it's a turbo, it's a 4 into 1 exhaust manifold- which you'd normally expect to yield better for top end power at the expense of mid range torque, and the header lengths would be tuned to obtain peak power at a targeted rpm.

So I'm guessing you are taking advantage of the scavenging effect to increase peak gas flow into the turbine at the top end of the rpm range, and hence increase peak hp of the engine...which makes perfect sense if you're planning to run a massive turbo on a two point something litre engine where peak performance will always be at the top end of the rpm range.

I'm still a bit confused over the whole heat thing though, I thought the key to big power was maximising heat input to the turbine...so you'll need to do everything you can to keep as much heat in the manifold as possible...ceramic coating and heat wrapping?

That is almost right. The longer pipe length works at low to mid-range RPM. For top end power the pipe length would be shorter
By keeping heat in the manifold that will keep the exhaust gases expanded so they will be moving faster and have a higher velocity coming into the turbo, this will spin the turbo up faster. The down side is there will be more back pressure on the engine so it will be harder for the cylinder to clear all the burnt gases.
This will work well for a road engine when you want the boost to come in early but with my setup the Motec will give me all the boost I want when I want, but I need as low a back pressure as I can get at higher RPM so I do not want the gasses to be too hot

[Nic]

Looks like that weekend it free, just have to see if and how the car is running.

Going to try this turbo out next year if it all stays together.

http://www.youtube.com/watch?v=GvVFxLkm-so

Are you still going with a GTX4294R Bob? What rev limit will you be running?

[bobhatton]

Looks like that weekend it free, just have to see if and how the car is running.

Going to try this turbo out next year if it all stays together.

http://www.youtube.com/watch?v=GvVFxLkm-so

Are you still going with a GTX4294R Bob? What rev limit will you be running?

Not at first no. It will be run at around 650hp as I have a turbo sitting here that will do that.
Max rev will be around 9000 if the cams will get me there, if not I may have to get some made

[calum4492]

u going 2 use a boot mount cooler bob?