Compound pics

[andy2]

I just added some more pics to the link.I'll let them do the talking :lol:

[RabbitGTDguy]

very nice

I want a holset

Joe

[malone]

The bores look much better now interesting head+precup decking pics too

[935racer]

Do you have access to your own mill? If so your a lucky guy, I sure with I had a nice lathe and mill, one day... Looks great andy, keep up the good work. Oh how are you supplying all that fuel for that much air? Giles custom pump I assume? Have you done any head porting or thought about a bigger/better intake manifold?

[andy2]

I do have access to a couple lathes and mills in our basement and much much more as well as someone who knows how to operate them properly :lol:,Oh the benifits of staying at home .You guessed it Giles pump for fueling needs.I've done quite a bit of head porting as well as that we plan on modding the intake for the the rebuild.

I've currently been looking for a proper AAZ headgasket,The Aftermarket doesn't seem to make one thats quite as good as the OEM one.Aftermarket ones are simply shims that are stacked together and the OEM has an aditional thin (.002") layer that wraps around the fire ring of the gasket making it impossible for any leakage between the gasket's layers unlike the aftermarket ones.I'll bite the bullet and pay extra for the real deal.Not saying that the aftermarket ones are not good enough, just that they are not as bomb proof shall we say :twisted:

[andy2]

I like the way this setup works and I wouldn't change a thing

Upon closer inspection of the k14 compressor housing/wheel I,m now thinking its a little on the small side for the hx30 to flow through it properly so to be safe I'll stick the k24 compressor back on.I figure it will spool as good anyways :roll:

[n2toh]

andy

All I have to say is that is one kick ass setup. Are you going to aftercool the first stage turbo before feeding the next stage?

What are the peak pressure ratios of each turbo for your designed flow rate?

[andy2]

Thanks, One big FMIC should do the trick,plumbing is tricky as it is let alone having two IC's

Basically to make 35psi boost It takes about 40psi (exhaust) drive pressure overall,I will probably do more testing in the future as things keep changing :twisted:.I had a very undeseriable rad hose Plumbing with way to many leaks as well as a leaking IC,So with a nice IC and proper plumbing It could be closer to a 1:1 overall pressure ratio.The k24's boost is regulated to 10psi so after the ported wastgate opens fully it does a good job of bypassing the needed flow the the hx30.

[n2toh]

Thanks, One big FMIC should do the trick,plumbing is tricky as it is let alone having two IC's

Basically to make 35psi boost It takes about 40psi (exhaust) drive pressure overall,I will probably do more testing in the future as things keep changing :twisted:.I had a very undeseriable rad hose Plumbing with way to many leaks as well as a leaking IC,So with a nice IC and proper plumbing It could be closer to a 1:1 overall pressure ratio.The k24's boost is regulated to 10psi so after the ported wastgate opens fully it does a good job of bypassing the needed flow the the hx30.

oh I see now what your trying to do. What I was asking is if turbo 1 has a PR of 2 or 14.7 PSI and turbo 2 has a PR of 2 your combined boost is 44.1 PSI. 2*2=4-1=3*14.7=44.1.

I thought your wastgate plumbing looked a bit confusing but now it makes sense, your not going after HUGE boost.

[andy2]

your not going after HUGE boost.

Well I would'nt say that,I've lowered compression down to 18.5:1 :twisted:.I'm going to get this engine to produce as much power as I can safely get out of it, If I need 40-45psi then so be it.

[n2toh]

your not going after HUGE boost.

Well I would'nt say that,I've lowered compression down to 18.5:1 :twisted:.I'm going to get this engine to produce as much power as I can safely get out of it, If I need 40-45psi then so be it.

this may be of some use. http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

use an AFR between 18 and 22, and adjust the specific fuel comsumption to get stock power then play with the boost.

[andy2]

Yeah as you've probably gathered I'm no turbo expert :oops:.

BTW thanks for website,I havn't seen one that detailed yet :wink:
I had roughly 140-145 WHP before,so it will be interesting to see what happens next.

[n2toh]

Yeah as you've probably gathered I'm no turbo expert :oops:.

BTW thanks for website,I havn't seen one that detailed yet :wink:
I had roughly 140-145 WHP before,so it will be interesting to see what happens next.

You should get ahold of Tdimister he has done a bunch more engine analyis than me, and gave me that URL. Do you by chance know someone that could adapt the not2fast calc to support staged turbos?

IE break it down like his format for each stage and allow adding an intercooler and water injection for each stage. or make it modular like have it ask how many boost stages and such.

Also play with the water injection option.

[QuickTD]

Andy's setup has controls on both turbo's, so sizing is not as critical as in a free running compound setup. Of course, you have to give up a tiny bit of efficiency for ease of tuning. In checking the boost/backpressure ratios and substituting the K24 turbine for the K14 he has almost achieved 1:1 boost/backpressure ratio and nearly the same pressure ratio across each turbo. I would call that exceptionally good sizing. I'm not sure that computer analysis will make it much better.

[vwmike]

I've actually made an excel spreadsheet for calculating compound twin turbo sizing while accounting for intercooling and aftercooling. Most of the parameters are able to be changed.

I sized things out for my own car and bought another turbo but am not quite yet ready to get that on there. It looks like with the stock turbo and a 60 trim T3 I should be efficient all the way down to around 20 or so and up to about 105 psi. Here is the second turbo I will be using



I don't think I will intercool it and just run a single aftercooler due to space and plumbing restrictions. So much boost can be generated that I see no reason to look for every single advantage there is to be had.