Here we go........





13B 4-port turbo needs to make 500HP@5252RPM ONLY!!!!! I say again, ONLY make the power at 5252RPM.....don't care about anything else, not spool-up, not any other RPM. How do I get there without breakin' the bank and/or the engine?!



AND.......





What is the necessary relationship between porting and turboing?







Thanks!

 

sounds like there is a bet going on.

 

This is for your aircraft? (I thought you fly boys usually ran more like 6000 or so)

Also I recall you have an S4 engine (correct?). It's not going to like that power level (irons can crack in the upper dowel pin area).



Bigger ports will allow you to make more power at the same boost level. Bridge porting may be out of the question for reliability reasons (bridges can crack). Peripheral may be doable if you have the facilities to make your own.



You'd need a giant turbo - maybe use a pair of stock TII turbos with upgraded compressors?



Check out these threads:

https://www.nopistons.com/forums/ind...howtopic=37740



and



https://www.nopistons.com/forums/ind...howtopic=22120

 

Good luck!



Even Demetrios was making less than 400 @ 5250rpm on his 768 hp dyno pull. Add another 500 RPM and he did it though.





Another thread

 

i would think the more porting you do the higher up in the rpm band its gonna move the power peak, same with the turbo.



i see a moderate sized turbo, running a lot of boost thru relatively mild ports, remember you dont have to go on to make 700hp@8000rpm, it can peak lower

 

From what I've been able to ascertain, the turbo is a Hitachi 18S-2S, and supposedly that is a Series 5? Either way, a co-worker of mine has the same rig except with:



TO4E 60:1 compressor

.84 A/R turbine

P Trim

HKS manifold

HkS 50mm wastegate

720cc primaries

1600cc secondaries

large intercooler

moderate street port

75 psi oil reg

fd seals





His last dyno run was 416HP at the rear wheels at 7,000RPM.







I'm trying to make the power at 5252RPM to match HP and torque....in aircraft, torque to turn the prop at speed is almost more important than HP. The point that I'm trying to clarify is when dealing with one needed power-position, is the porting and normal type of turboing required, or is some kind of hybrid turbo best for making power at that one point(5252RPM?)



Thanks!

 

Well I would guess that you'd need a pair of the HT-18's with compressor

upgrades to make that kind of power. Of course then you don't have a

choice for turbine AR.

You're kind of in uncharted territory, trying to make your power at 5252. I

would think you'd be okay to run a higher RPM and just use the appropriate

PSRU ratio - the prop doesn't actually know the RPM/torque of the engine

anyway, just the RPM/torque at the prop shaft (of course if you're doing a

direct drive those #'s would be the same).



Still I would think that for aircraft use, you don't really want to run massive

boost due to the unavoidable adiabatic heat increase. To be able to move enough

air to get the torque you want I would think you'd have to go peripheral:

http://www.vintagerotaries.com/FORUM/viewtopic.php?t=86



If you have access to a milling machine it's really not hard to cut the

intake ports.



You really should replace that S4 rear housing with an S5 (I don't know if it's

necessary to change the front one as well... anyone?). There's a very good chance

of breaking it. At the very least, do the "loop line modification" somewhere

on the forum and plug the dowel pin oil passages so if the housing cracks you

won't lose your oil.

 

the s5 irons have larger ports and runners stock.

 

Here's a thought: Have you considered using nitrous to meet your short duration power demands? Lots of torque to be had there, and it has been used successfully in 13B aircraft applications.

 

Yes......had long discussions with NO2(the company).......def can be done, but limited use and bottle weight an issue. I'm talking with Racing Beat right now about their PP/turbo 3 rotor and if it would be possible to use their PP housings & a particular turbo to make the power I need with my 13B TII .