Taufu

Hi,
My car is currently running a b20 vtec with a vf29 turbo.
I just bought a jackson racing supercharger.
I wonder anyone have done this type of setup can give me some tips on getting it done.
My turbo and supercharger going to run in parallel, for example my turbo is boosting one bar and my supercharger only produce 0.7 bar, how can both of this works together?
Thank you.

F22Master

You can NOT run a turbo in parallel with a JRSC....

NotARaCist

iTrader: (1)

Oh boy, I hope you have more than just a stock rotating assembly. A stock motor is going to go boom with a quickness doing that.

Yes, a handful of people around here have done it. It's called twincharging. I believe the last person to do it said that they got a better powerband by removing the supercharger. IATs become a serious issue. But as F22 said, no, you can't do it in parallel (unless you want to do a shitload of custom fab work). You would have to do it in series.

Taufu

Thank you for the useful information...

Any idea how to turn it into a series? anyone done it before?

NotARaCist

iTrader: (1)

As I said, a handful of people have. You install the supercharger just like you normally would, then install the turbocharger just like you normally would. The physical "how to" is literally that easy. The turbo compresses air, that compressed air is fed into the supercharger (after going through an intercooler, hopefully), and the supercharger then compresses that air even more before feeding it into the engine. The hard part is finding a tuner who is willing to tune it, and is also competent enough to tune it. Compound systems are no joke.

Taufu

Thanks for the advise,it really helpfu. Lets assume that jackson supercharger and the turbo is running on series and the supercharger cut off boost at 0.7 bar and its read the boost level from the manifold, and my turbocharger is boosting at 1 bar, any idea how do i run both at the same time?

m4xwellmurd3r

Pretty sure it doesnt work like that. 0.7 bar boost at the manifold is 0.7 bar boost even if you cram a turbo on top.

NotARaCist

iTrader: (1)

Oh but you'd be wrong. It's funny what happens when you start running compound systems, with one feeding already compressed air into another. Check out this article from Garrett, and look at the math behind calculating pressure ratio. When you're feeding the system ambient air, inlet pressure is 14.7 PSI. Feed it air from another turbo running at 1 BAR, and suddenly your inlet pressure is 28.4 PSI. Run the supercharger at .7 BAR, and you have a pressure ratio of ~.88, instead of the pressure ratio of .7 you would get from .7 BAR.

...if my math is right. It's 4 AM, and yes, I am oversimplifying by ignoring pressure loss, assuming sea level, and ignoring the increase in IATs. Point being, compound systems have a higher pressure ratio out of the same boost levels from the final boost source.

m4xwellmurd3r

Hes saying it starts bypassing at .7 bar though. Since he said its cutoff is .7bar it seems like hes saying it has a bov of aorts that bleeds of excess pressure?

Thats how i read it.

Unless he means thats its peak boost, in which case yours is more or less correct.

wantboost

iTrader: (2)

The bypass only opens under vacuum to reduce parasitic drag from the supercharger during low throttle cruise.

The pulley determines what boost pressure the supercharger produces.

Taufu

If so i still could use a turbo on the supercharger.

Taufu

Yup im talking about peak boost.

wantboost

iTrader: (2)

Without an intercooler after the supercharger or water methanol injection you're going to have insanely high IATs out of the supercharger. High IATs = more prone to detonation, lower timing advance, less power, etc.

Plus with the OEM B20 cams you'll make absolute **** for power. Then again if you get this setup functioning properly then depending on the boost pressure the turbocharger runs and what pulley you have on the SC you could easily exceed the "safe" limits for stock internals. At which point you will break something like a sleeve, ring land, rod, etc.

Plus you need to be very familiar with compound setups. Like you can't run a pressure signal for the turbo anywhere but the compressor housing because the reference pressure after the supercharger will be much much higher than anything the wastegate could handle so it would basically stay wide open then entire time positive pressure is being made.

This really isn't for people on stock engines

Taufu

im running on a sleeved and full forged internal block and i have a water methanol setup in my car. i just wonder that the compressed air from the turbocharger can be compressed again in the supercharger or not. Will it gain more power or going to build a power which is worse than a normal turbo setup.

OneBadTurboCRV

Between these three links, you should be able to take it from here OP:

https://honda-tech.com/forced-induct...etups-2861610/

https://honda-tech.com/forced-induct...build-3196834/

https://honda-tech.com/forced-induct...wners-3226822/

50psiboostinteg

You can run both together, I have done it and can say from first hand experience it builds boosts fast and has great usable power but it is a toss up as may or may not go well, my setup is 15g turbo with the m45 supercharger and it ran well but after three months had to send the blower to get rebuilt as oil leaked out, still waiting on the rebuild and trying to source a blower for it to get it running again.

Geis

He hasn't ran any setup at all btw ^

Tony the Tiger

I've done quite a few twincharged setups on various platforms, but I should be able to group all the info together to make it a straight forward post.

Twincharging in parallel:
- No IAT issues from air compressed by SC
- Does not hinder power if SC is disengaged once turbo boost surpasses SC boost
- extremely complicated to set up (need one-way gates/valves, separate air path post-SC)
- Does not provide better turbo response at PSI greater than what the SC can provide (turbo recovers the same fashion as if you had no SC beyond the pulley PSI). If your turbo is large enough that is has trouble winding up to full boost from say 10 PSI to 25 PSI, then twincharging in parallel does not improve this issue.
- Wastegate PSI at the turbo will be your final boost level


Twincharging (compound)
- IAT issues, but same as typical SC setup if you chose a low PSI pulley
- simple to set up
- assists in spool up and turbo response across the range (turbo will spool up similar to your net gain from S/C + base engine output).
- boost is compounded (wastegate boost + SC boost). If your pulley is 7 PSI and your wastegate is 20 PSI, your total boost is pretty much close to 27 PSI.
- parastic drag from SC still applies, and the math sucks when you have a 600WHP setup and the S/C is in fact, still stealing about 8-10% from the crank. If you lose 10% torque from your crank pulley on a 600WHP car that revs to 9000RPM, you are actually losing about 50 WHP due to the SC. Boost PSI vs WHP will begin to look terrible the higher you go.

Although compound twincharging setup is the most effective way to spool up a turbo as if you had a bigger engine... e.g. when I twincharged my Integra (B18C1), the spool times and characteristics were very similar as if I had a 2.4L motor of similar VE. The math is based on the power gain from S/C alone on the B18C (which was 175 WTQ and 170 WHP at 5000RPM -- a range which a turbo will likely be spooling), and thus it had the ability to spool up and work the turbo as if I was almost a K24 motor in comparison.
I had a 71mm HKS T51R turbo and I managed to spool it up by 5500RPM up to 20 PSI.

There was no big concern except for typical heatsoak problems associated with non-intercooled boost. Because IAT losses are consistent throughout as a percentage, I noticed once the blower heatsoaks, I lose a lot of power from a 600WHP car. It's not bad when you are speaking of a typical JRSC setup that loses about 15-20 WHP from a 240 WHP car; but with a 600WHP car, that percentage of loss becomes almost 50 WHP loss and definitely noticeable on a highway pull.

I had a 7 PSI pulley on mine, so it was safe to run, but the power still sheds away like a typical JRSC setup. Eventually I removed my setup not because it runs hot, but beacuse it was hard to maintain and service. It felt like I was going through belts/tensioners like a JRSC car + typical turbo maintenance like exhaust manifold gaskets and minor oil leaks and such.

The car was a daily driver at the time, and I was spinning tires in 1st gear anyway so I felt there was no need for all that low-end torque and response unless I was towing a boat or if I had a 2 speed transmission or something...lol

bigG

iTrader: (6)

Can you be more specific on the build it self like stock ports, cams, exhaust housing? And have you done it on a smalller turbo?

TheShodan

iTrader: (14)

I'm sorry, but I don't see how you can ask for more specific feedback than this.... His cliffs even say it wasn't worth it.. What you're asking is only a small part of relevancy in the grand scheme of its use.. Cams, exhaust housing (worrying about back pressure) is not as relevant as you think in his example.

bigG

iTrader: (6)

He said for him it wasnt worth it for one and two i wanted specifics on his build to understand the breathing characteristics of the engine like did he use a larger exhaust cam to get the gases out faster or relied on a standard cam profile and used a larger back housing because twincharging produces alot more exhaust gases.

wantboost

iTrader: (2)

His engine had headwork and cams. It took a lot of time tuning the setup to get it to even run properly. There's a much broader range of operation in positive pressure with these kinds of setups, especially at partial throttle. If you don't take the time to fully tune these kinds of compound setups it will run like absolute dog ****. Tony is one of the very few I know who could even remotely pull something like this off.

If you don't tune or you don't know a competent tuner don't even attempt a setup like this. Installing the components is literally only half of the battle.

Also like tony said the other big problem is post-SC IATs. If you aren't running an LHT intercooler setup then even at moderate boost pressures from the turbo with a sub 10psi blower pulley you'll see very elevated IATs almost to the point where you negate even having the blower in the first place. Water/methanol injection is the cheapest and easiest way to combat elevated charger discharge temps but even a moderate injection rate ultimately leads to the coating on the rotors flaking off which reduces efficiency and further raises IATs.

TheShodan

iTrader: (14)

A larger exhaust cam wouldn't have changed anything to that degree level to expel exhaust gases any faster than if he had just a turbocharger. In the end, as his notes stated, the amount of pressure going to the exhaust would remain the same consistently.. No exhaust housing would have changed that, any more than just one power adder. He wasn't close to any backpressure issues to warrant it.

Larger camshaft doesn't change exhaust energy rates.. The turbo itself does. The exhaust cam works to change tuning events to keep the exhaust gas that's in the exhaust cycle of the engine to not mix with intake air..not change exhaust flow rates.

Tony the Tiger

Shodan and wantboost pretty much summed it up... For turbine sizing, cams/engine related things, you will base your turbo selection on the engine's output with the supercharger.

On my post, I have mentioned that the engine had very similar characteristics as a K24 motor. Your turbine selection will have to reflect on a 2.4L motor and not a 1.8L motor. For example, you would want to choose a GTX3576R rather than a GT3076R if it is twincharged.

You would not want staggered cam (larger exhaust cam), because your supercharger + motor is behaving like one altogether. Your cam selection, will be based on what the engine is working against in terms of backpressure. You would want a turbo cam, small duration and high lift. The only advantage is that you can dial more aggressive overlap at midrange RPM because the supercharger is a positive displacement unit, and no pressure pulses can ever escape backwards through the intake valve. You can improve spool time with earlier intake advance and not feel the losses at higher RPM.

Eventually, you won't enjoy the setup if you are actually making 500+ WHP. The IAT heat losses becomes a significant figure at higher power levels.

If you are looking for 400 WHP levels, as funny as it sounds, our current turbo technology and billet selections can pretty much almost nail it down with great spool with a 1.8L or 2.0L on turbo alone anyways.

It is ONLY worthwhile if you are planning on running 67+mm turbo and 600+ WHP levels. However, at those power levels, you will hate the IAT heat losses.

So yeah, not worth the effort to twincharge a Honda these days.

bigG

iTrader: (6)

I actually have a fully built setup with lht on the side for a 700whp but the chassis itself is over a year from being done. I will probably post info on that build as it gets closer to completion.
I had a b20 vtec with a gt2876r in my daily That i loved the response but wanted more power so my goal is to get that in a 450whp setup (really just looking for the right turbo at this pointl) with a crazy powerband. This twincharge setup will not have a lht manifold but pressure will be no more than 5psi max. But i will update my post in a few months and let you guys know how it goes, hopefully i can tell you guys it pulls like a allmotor v8 lol.


And thank alot for the info i was thinking the cam selection would be for a turbo setup and not somuch jrsc but wasnt 100%. But to give an idea of the cam selection it will be IN 12.5mm lift 250 duration @.50 12mm lift 248 duration @ .50. And the head is fully ported (made over 320 allmotor)