Camshaft choice for B21 with TB41 turbocharger

[whilliam]

What statement was not true? You think that i meant that a smaller turbine will give more power?

I have to think that is what you said, since that is what i read Anyhow the statement is false since it says that bigger compressor and smaller turbine will raise both torque and power. Truth is that biggest ever turbine will give maximum torque and power as long as we are happy with spool.
Regarding compressor size the one that have the highest efficiency will give max power and that means it must be a match to the engine and power demand (not bigger=better)

I would never have thought that someone would not recommend throwing an old dieselturbo in the garbage.

Nice! By this thread you have learned something new then. REMEMBER, the ones that tell you to throw away a turbo and not is capable to calculate it´s pros and cons. They are Turbo manufacturers or turbo suppliers and if you do not throw away old stuff they could quit their work

It could also be a "youngster" that have seen a lot of advertising and thinks that the new stuff is a "must" if you want top of the line power (wich is wrong)

Try and scan this forum and you will find a lot of people building cars that outperform many others and they use "diesel" turbos (actually there is not such a thing as dieselturbo, it is just different sizing)
Also many manufaturers that sell "race" turbos, just pick stuff from their diesel-line and put them together in right dimensions (look at Borg Warner S-series)

From what the threadstarter describes it is almost the same as the 18T turbo on a B230 with agap (maybe) camshaft that I tuned today. VE falling of after 6200 and around 330 hp at 1.5 bar of boost.

On my behalf, i immediately understood that the turbo and/or engine was not maxed out, that is why i did not recommend anything until i get a better input.

[Stefan Ingi Jonsson]

@quattro Can you give me an example how you would set up the ignition map so I can do some modifications before I go to the dyno?
Yesterday I modified the MS2 and put an extra analog input circuit so I can connect the KS-4 knock sense module too it and datalog knock

@whilliam regarding the camshaft and turbo relationship, if I understand what Jens has says about engines that have low back pressure vs boost pressure then a camshaft like k cam or STS 247 for example would give me more power if the engine can rev to 7500, but if the engine has more back pressure then boost pressure then you would use a T cam so basically cams with high overlap will not work well with high backpressure.

Also do you know what is the difference is between cams that have more lift and duration on the exhaust side like the KG2T and the K cam? there must be some difference between setups that these cams would work best in from the perspective of the most average power output.

[whilliam]

What Jens have said is true but it does not affect the situation if you can choose the right turbo. Turbo will make thousand of percentage in difference and the camshaft will give you figures in the 5-30% region.

Your turbo is not maxed out yet, you need more boost at high rev. A camshaft change will not do as much as higher boost.

[Jens Gustavsson]

Hej ni för köra googel translate jag är grymt dålig på att skriva på engelska sorry!

först jo det är nog inte "rätt kam" ska kolla om jag mätt upp exakt den kamaxeln i min kam mätare för att få exakta data. vad lyfter den in och ut och nock vinkel mm? dur vid 1.25mm?

sen kompan?? en B21 A har kring 8.5:1 i kompa standard vad jag mins? sen en 3mm packning och kanske lite portning i förbränings rummet?? är det inte typ 6.5:1 då?? låg kompa kan verkligen ta död på effekten och responsen på en i en i övrigt vad jag kan se en rätt fin motor.

fins inte E85 där? eller ren etanol? det är en ny värd som öppnas då i både effekt, körbarhet och hållbarhet. då kör man 10:1 utan problem med de laddtrycken.

fins nog en del i tunigen på förtändnigen där också.

hade gärna hjälpt er i dynon men ni bor ju lite långt borta

mvh jens

[Jens Gustavsson]

Beskrivning

Art.nr: KG2T
KG2T Turbo kamaxel för turbobruk.
Ökar dragvilligheten på låga varv - vilket märks framförallt vid stadskörning.
Ger även bättre dragvillighet på mellanregistret. Går att varva längre

V-LYFT IN 10.5
V-LYFT UT 11.9
NOCKVINKEL 114°
DURATION 300°

låter som en väldigt tam kam ger nog inte mer än 120 sug HP i er nuvarnade motor. med en STS kam av rätt sort så blir det mot ca 150- 160 sug hk och med mera kompa säkert mot 180+hp.

räknar man sugmotor HP x PR (laddtryck i bar +1) så ser man att då börjar det bli effekt att tala om.


mvh jens

[Stefan Ingi Jonsson]

Hello jens, no problem you can write in swedish I use google translate

About the CR: The pistons are flat, standard 531 head(52cc I think) and 3mm headgasket so I calculated 8,3/1 CR.
I just ported the runners not the chamber but I have been thinking about using 1.5mm headgasket and remove a little squis area, what do you think about that??

It would be great if you could help me with the camshaft , do you need more information regarding the camshaft??
Do you need a another camshaft in return for STS 247??
If I use the STS 247 can I use the same springs that I use for KG2T??
Where is the recommended redline for this B21??

[whilliam]

Before you decide to change anything, please, tell us what your goal/demand is. There is no reason to first change the camshaft wich will only give you a few extra Hp and then be FORCED to upgrade or change the turbo.

If you are happy with a Hp peak at around 6800 rpm (around 435-450 Hp) then you could reach it with the stuff you have now. Beyond 450 is almost "non possible" with that turbo and low compression.

It is much smarter to ONLY do something about the turbo if your goal is more than 435-450 Hp. The camshaft you have can, easily, give you 550-600 Hp @ 7500 rpm with a better turbo. (more boost)

I do not like to make comments when the set up is never maxed out! The best value for work/money is to use the stuff (to it's max) that sits there before upgrading

For best performance at high revolution you must make a tapered squish to control the forces from the end gasses burning process. If you keep a flat sqish it should be between 0.8 to 0.9mm or over 2.5 mm ( i do not like that much since it makes the burning process sluggish, but it is a must because in between numbers will give detonation problems)

Low compression and low squish-effect does demand high boost to come at it's best.

Remember squish does two things: first it "speedens up" the burning process (makes it possible to get high efficiency at late ignition) and second (maybe the most important at turbo-engines) COOL the end gasses so they can not detonate.

låter som en väldigt tam kam ger nog inte mer än 120 sug HP i er nuvarnade motor. med en STS kam av rätt sort så blir det mot ca 150- 160 sug hk och med mera kompa säkert mot 180+hp.

räknar man sugmotor HP x PR (laddtryck i bar +1) så ser man att då börjar det bli effekt att tala om.


mvh jens

Let us do some calculation then:

First, 120Hp to make 350Hp @ 1.6 Bar does not line up with the figure we already have....... (350/2.6= 134.6Hp) Here is one more thing to concider, early in this thread i asked for boost-figure at max hp, we do not know for sure that there is 1.6Bar @ 350Hp

Jens says a camchange will give up to 160Hp (as N/A, math gives: 160x2.6=416Hp) But i say more boost: 134.6x3.1=417Hp

There is one more important thing (when you think that you can calculate N/A Hp into Turbo Hp) REMEMBER: N/A gets their horsepower gain from strong pulses at ex. manifold, when you upgrade the cam at N/A it will give a lot better effect than on turbos and the reason is that theese pulses can work harder to start the inlet process.

There is several names for that function, many call it the 5:th stroke. My personal best name is "N/A - engines turbocharger"

It is ALWAYS better to compare torque figures than Hp figures, because you could then assume that all torque beyond 100Nm/litre does come from the "N/A - engines turbocharger" and not from flow-figures.

From another POW up to 100Nm/litre is possible without boost (just flow) but beyond that one needs bost in some way - may it be extraction/suction-effect or blower or turbo.

[Stefan Ingi Jonsson]

whilliam how would I make a tapered squish on this motor and keep the CR down below 9/1? and what dimensions should I use? and should I use the whole area? 1.25mm to 1.5mm for example?

Regarding the cam change is that I want to dyno this setup too get most out of it and then change the cam and do another dyno session and see what works best

[whilliam]

Tapered is in two ways, one is to direct the gas at favourable direction (on low Hp to make part-throttle efficiency, we want to make them hit the spark plug, but high Hp we want them not directly on plug but we still want to control them instead of leaving them to do as they like from one cycle to another)

The other way is to make them slower when reaching cylinder center, if distance is equal all the way the result will be more faster and faster travel, but if distance is growing when going against center you can make the area of "flow" bigger when reaching near center.

I can understand that it is fun to proove/show people how much power you can get with this and that engine and this and that turbo, but it is big cost (both work and money) it will be easier if you let us guide you towards a specific goal. I can make the turbo perfect for what you need and other people here is good at tuning and make judgement for the camfigure and timing.

I still stand by my point in last post: there is no perfect "ready made" turbo for you but with good help we can choose one that is pretty near perfect, we just need to know what you want (your goal in power and driveability) The camshaft can, for sure help a little but it is not comparable to turbo changes.

[quattro]

@quattro Can you give me an example how you would set up the ignition map so I can do some modifications before I go to the dyno?

I would take away the columns labeled 800/1500/2500 and add columns at 4500/5500 and 6500. The box is interpolating between the figures in nearby columns so down where nothing much is happening you don''t need that many columns. But I would leave the ignition values as is. The place for adding more ignition is on the dyno.

On the dyno I would start with boost and fuel. Getting the fuel correct for every load cell and increasing the boost gradually. When further increases in boost do not produce any power increases I would stop. If I felt that level was putting too much stress on the turbo or the engine I would lower the boost a little and then leave it there.

Then I would test with advancing the cam 2-3 camshaft degrees and see what happens. Usually you get faster spool and better mid range. Sometimes you gain on top, sometimes you lose on top. Test till you see in what cam position you get the power and torque curves you prefer. It might be in a neutral position, or it might be 6 degrees advanced. But you won't know until you've tested for it.

When that has been done I would add 1 degree of ignition straight across all rev columns to see what happens. If power goes up I would add another one. I would go on adding more ignition until you get no more power increases, or until you get knock at a level you cannot hear but a knock sensor can register. There i would stop, take away a degree or two, and then leave it.

Then if boost is too slow I would test a wilder cam. If mid range is weak I would make a cam with same or a little less duration but with tighter angle between inlet and outlet. If top end power is too low I would get a bigger and better turbo.

[Kadett4wd]

I had very succesful results with a precision pt6265 billett impeller gen1 on a b230 engine.
Actually spooled quite early and engine produced a lot of power and held it way up in rpm range.

[Stefan Ingi Jonsson]

Hello,

I have a small update on the car.

We put a KG004 cam and an intercooler from KLracing (550x300x115), also 3" plumbing from turbo to intake.
Then there was much more power with the KG004 than KG2T (the car would lose traction in 2 gear when the turbo spooled up at 4000 at 1 bar), but ​the engine did not knock on the rev limiter any more! why?

After tuning the VE table, it showed much more flow at high RPM and across the table.
The IAT went from 40°c over ambient temp down to 5°c when we did full acceleration from 0-160kmh (with the new intercooler).
We tried more boost with the new setup but the turbo(tb41) maxed out at 1.4 bar (even with the wastegate disconnected).

Then we put Holset super Hx40 from KLracing (Compressor: 60 / 86mm, Turbine: 75 / 65mm, 16cm2 Exhaust housing, t3 twin entry) on the engine and tested at 1.5 bar boost, it would spool up much faster but started to build boost at the same RPM as the TB41 (2000-4000rpm=0-1.5bar).
The backpressure was slightly less than the original setup (KG2T,small intercooler and TB41).

This is off topic but we put a rollcage in the car and there is noticeably better traction when accelerating (maybe little heavier in the rear?).

The Injector duty cycle was around 80% at 6500rpm 1.5 bar 11.5 afr ignition timing around 20 degrees.
When I increased the boost to 2 bar the duty cycle went up too 95-99% at 6500rpm 11.6 afr ignition timing around 17 degrees(still using 98RON but using octane booster).

Do you think I need bigger Injectors or is there some other reason why the duty cycle is so high?.
And do you think it's safe to dyno the engine at 2bar like this?

Me and my brother went for a test drive, he was driving his Tesla model 3 performance and we did a roll race in 3 gear(90-160kmh) the Volvo lost traction but the Tesla did not pass , then I broke an axle when accelerating in 3 gear few minutes later... (the surface probably had more traction that time).

I booked a dyno session few days ago but when I got there the guy told me he realized he doesn't own 5x108 adapter for the dyno, so now I need an adapter from 5x108 to maybe 5x112 to dyno the car.

Any advice is greatly appreciated .

P.S sorry I posted so late

[mattias]

You probably need larger injectors, mathematically 80% at 1.5 bar = 100% at 2 bar. You can always double check that the return flow at the tank is what the fuel injectors flow (970x4 = 4 liters/min) at base pressure 3 + 2 bar boost = 5 bar fuel pressure. Apply 2 bar pressure to the top of the regulator with an air compressor in the garage and force the fuel pump relay to run, and let the fuel flow into a container.

I would go the dyno and let the tuner make sure you're not near the knock limit, the stock B21A pistons will have a better chance of survival.
Beware that ignition timing based of a distributor trigger is not the best idea when pushing things hard. It's fairly stable on the red block but something to consider.

Where the N/A engine makes the maximum torque is where it will be most susceptible to knock (4-5 krpm) and let that decide how much boost it can handle at that point and ramp it up from there. That should be maybe 500 Nm on 98 RON, unless you employ methods for charge cooling.

[Stefan Ingi Jonsson]

Thank you for responding so soon.

I'm using GSL392 fuel pump and according to their flow/pressure chart
(https://walbrofuelpumps.com/walbro-gsl3 ... .html.html) the pump flows around 56 GPH at 72 psi which is 212 LPH.
If I calculate the flow of the injectors 970x4=3880 cc/min which is 232 LPH.
I think the max duty cycle should theoretically be 212/232=0.913=91% if this flow/pressure chart is accurate right?
Do you think its possible to use the fuel pressure gauge during the dyno session?

Regarding the distributor, are you talking about mechanical play in the gear?

I don't have an electronic boost control so I can't control the curve but is it not possible to have less ignition timing down in the 4-5k rpm?
(its 12 degrees at 4K 310 kpa load in my map).

[mattias]

You should consider upgrading the pump to Walbros later turbine pump (GST450) instead, that will get you the flow you need to have some margin.

Distributor axle is gear driven by the intermediate shaft which is belt driven from the crank. There is usually not a huge issue on the Volvo but an improvement would be the standard flywheel 60-2 trigger.

I would advice you to get boost control working, it makes a huge difference. It's better to run the engine where it wants to produce torque instead of retarding timing for the wrong reason.