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Had anyone use this intake manifold, Kl Racing extreme plenum?

Jussi Alanko

Member
Joined
Jun 5, 2020
Location
Finland
I'm thinking to buy this intake manifold for my b21t project.
Has anyone tried this kind of manifold here?

In Finland, where i live, one guy uses Kl Racings cheaper options in 750+hp 740 drag car, but at least with 40psi of boost (2.8bar) it develops cracks etc etc.

This "extreme" manifold is cast aluminum, and i think it does not crack so easily compared to cheaper welded one.

This is the manifold, i know it's expensive, but hobbyes are expensive! I have already spend a 2000? from my engine containing boring&honing, new pistons, new h-profiles, ported 530 with 46/38 valves (flows about 200/170cfm at 28"), double springs, 280 *0.050" / 12mm camshaft and of course new bearings and gasgets.

https://shop.klracing.se/sv/artiklar/volvo-8v-plenum-_-insug-for-80mm-spjall.html

05019.jpg


Rest of the engine combination contains Holset hx40, tubular exhaust manifold, do88 intercooler (not the crappy China cooler) and Microsquirt with wasted spark ignition.

My goal is to make at least 400hp with minimum amount of boost. Engines useful powerband is 3500-7200rpm. In this type of engine it's had to has at least 170hp in NA form, which i think is realistic with this kind of head flow and camshaft, but it needs good intake and exhaust manifolds. Engines static cr is safe 8.5:1 (i do not care about idle or low end torque in this application. This car, 244, is a summer toy, not a daily driver. :roll:

What are your's opinion at this intake???
 
This should be interesting info since i was thinking of buying the same intake.

However in my build, i tested a modded stock intake configuration, it may be worth checking it since it is also a B21 going up to around 420 whp, but with stock valves using 100 octane fuel. http://forums.turbobricks.com/showthread.php?t=310632

Also i think that 80mm TB of this plenum is a bit large for this kind of power. You gotta check air velocity in the pressure hoses/TB using some online calculators.. too slow or too fast is bad !
 
Rs tuning Bergen in Norway has tested both the kl-racing extreme plenum and the k-jet intake. They saw no gains from the extreme racing plenum compared to a k-jet intake. An added benefit from the k-jet intake is how stock it looks and the ability to run the injectors in the head. They used a 65mm throttle body, I think they used a 90 degree 3 inch bend to move the throttle body from the stock position. They did a test earlier this year:

Translated:
B230
Machined original pistons for lower compression.
531 Head, 100% NOT!! ported, only machined for injector holes and fitted bigger valves and uprated springs. (46/40)
BSRT5+ cam with an adjustable pulley. 2.35mm lift on the inlet valve at TDC.
K-jet intake with a 65mm throttle body.
940 manifold (90+) with a T25 adapter.
EFR6258, A/R0.85 turbine housing.
DO88 intercooler.
3" exhaust.
BOSCH 044 fuel pump with proper connections.
Good 750 ccm injectors.
Block mounted distributor with American ignition box.
Haltech EFI.
98ron lead-free pump gas without tricks.
Upgraded clutch.
204 Nm and 155 hp measured on the hubs from the theoretical NA engine.
the best peak numbers were 397.7hp measured at the hubs.

The best results for the theoretical NA engine were achieved with 1,3bar which resulted in 364hp measured at the hubs with 98ron, again without tricks. 364hp/2,3map=158hp.
 
I'm thinking to use a 70mm throttle body and 2.5" intercooler piping.
Or 80mm throttle body and 3" intercooler piping.

I don't know yet i had to make some calculations.

I like a looks at this manifold and it will be a perfect fit with ported head, i need to think this subject.

Because i use a holset hx40 or hx40 super with tubular manifold, i had a opportunity to hit the boost up if i wan't to. I mean that i have kinda opprtunity to make bigger power if i update the rear end also.

With m90 and 1031, 400hp will be just within the limits of transmission and rear end.

But: bakaxel.se sells zf gearboxes with redblock bellhousings at 700€, they can take 800nm of torque. So, maybe i build an Evo2 someday...:cool:

I also think i use a do88 intercooler, they had good reputation and they have measured pressure drops and flow rates.

I'm starting at 1.6bar of boost (23psi), then dyno will tell you if the build is succesful or not...
 
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I writed this subject to s?varturbo forums, and Jens Gustaffson says that in 420hp engine, it makes 25hp more with this extreme manifold, compared to original intake.
 
IMO original manifold has too restrictive TB. It isn't of course the best design, but if you fit a larger TB it works. I also have noticed no important EGT difference on the cylinders.
 
dyno will tell you if the build is succesful or not...
When do you get to try it all out? :)

I writed this subject to s?varturbo forums, and Jens Gustaffson says that in 420hp engine, it makes 25hp more with this extreme manifold, compared to original intake.
Nice! Just need to be careful with the throttle body sizing because it?s going to be hard to drive around at low rpm if you?re over 65mm or so. At least, that?s been our experience in our NA application.
 
I use 70mm tb. It is the smallest option.

I also use a 3" intercooler piping, then there will not be any tapered hoses.
Only taper is from turbo to a 3" pipe.

This is a 3 years project, i have not much money so i build it by paycheck to paycheck style.:roll:
I can spend something about 700€ per month.
Example: at this month i buy a turbo, in december i buy a intake manifold, in january i buy a exhaust manifold.
Etc etc.:cool:

I have already spend something about 2000€ at the engine.
When engine is ready, i start to rebuild brakes, then in next summer i weld all the rust from chassis.
Here in finland is quite cold in winters and my garage heats up with straight electricity heater, so it is very expensive to warm up. This is why i build my engine in different place, i use a warmed little warehouse.
 
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