B5244T tuning capability

RaydenOBD · Post by **RaydenOBD** » 29 Dec 2023, 08:10

Hello everyone,

I just got a C70 from 2002 2.4T ( B5244T ) i would like to know what are the weak points of the engine, i saw some people running 300hp without problems other that bend rods.
I was planning on going 300hp ish with an 18T.

Thanks,

Post by **Chuck W** » 29 Dec 2023, 08:50

Manage your boost regulation and you shouldn't have an issue with bent rods.

We have the same engine in my wife's 850. We don't have it cranked up to 300hp, but it runs well and I do like the added bump from the higher static compression for general driving.

Post by **scot850** » 29 Dec 2023, 09:02

My 2000 R is supposedly running over 300 bhp on a Rica tune and it has a 19T as standard. Limitation is the auto transmission that is only rated to around 320 bhp

I know a guy locally that has an 850R with close to 500 bhp and so far no issues. Back in the UK before 2000 year there was a gy in Scotland with a TWR built 850 with 500 bhp and no issues. Chuck is spot on with it is how you control the engine that is the issue and not over boosting.

Good luck!

Neil.

dikidera · Post by **dikidera** » 29 Dec 2023, 09:15

Well all 850r and similar ran the 2.3 block, which had thicker cylinders. The 2.4t has the standard 83mm bore or thinner cylinders, so one must be very cautious about not cracking the block.

Post by **Sveedy** » 29 Dec 2023, 09:26

My understanding is that the older N style engines were more pron to bending rods. RN not so much so. But 300 is totally doable with either one. It's going to come down to your tune.

RaydenOBD · Post by **RaydenOBD** » 29 Dec 2023, 10:01

Thanks for the answers but i don't think R engine stats are relevant in my case since the B5244T especially seems to have weaker rods than most white blocks.
Even if it's probably too much i like running the safest setup possible, but changing rods would be the best things to do without talking about cost etc.. ?

Chuck W wrote: ↑29 Dec 2023, 08:50 Manage your boost regulation and you shouldn't have an issue with bent rods.

We have the same engine in my wife's 850. We don't have it cranked up to 300hp, but it runs well and I do like the added bump from the higher static compression for general driving.

Saw you're running a 16T, you must be around 250-260 ?
nd talking about boost regulation of course i need a proper tuner, and aftermarket TCV for more precision ? or the whole thing rely on the tune it self ?

Sveedy wrote: ↑29 Dec 2023, 09:26 My understanding is that the older N style engines were more pron to bending rods. RN not so much so. But 300 is totally doable with either one. It's going to come down to your tune.

Thanks for that info, didn't know about N an RN, just read RN comes with forged crankshaft and rods is that true to all RN blocks ? cause it seems strange that forged rods can bent at 300hp

Post by **Sveedy** » 29 Dec 2023, 10:23

I don't see any reason to tear into your engine just to replace the rods. I think the bending of rods comes with over boosting at low RPM's, so it's just getting the right tune to get the balance you want.

RaydenOBD · Post by **RaydenOBD** » 29 Dec 2023, 12:41

Ok fine !
I searched for hours and hours on the net, and i couldn't find a very clear answer.

So thanks a lot for your time gentlemen.

Post by **Chuck W** » 29 Dec 2023, 14:33

RaydenOBD wrote: ↑29 Dec 2023, 10:01
Saw you're running a 16T, you must be around 250-260 ?
nd talking about boost regulation of course i need a proper tuner, and aftermarket TCV for more precision ? or the whole thing rely on the tune it self ?

I honestly have no idea on the power.

We're just using the standard Pierburg TCV (The "Porsche" one) and just controlling the TCV Duty Cycle Pilot Control and the Target Load Setpoint in the tune.
Don't get aggressive with boost targets at lower RPMs and throttle position, and you will be less likely to cause problems. The overall tune does need to be sorted, of course.

The higher static compression gives the engine more "grunt" off boost at lower engine speeds with less (or no) boost, so it makes the car feel a bit stronger off the line.

Post by **scot850** » 29 Dec 2023, 15:53

The standard Volvo/Pierburg is TCV is only stable to about 12 psi boost and gets flaky above there. So if you are running that you should be fine.

The 00 R came with the standard TCV and a claimed 261 bhp. When I bought the car it had the Rica tune and a supposed 312 bhp and around 300 ft/lb of torque. Are those real? Who knows but the car is fairly rapid. The car is running the IPD boost TCV and from what Volvo told me it is running in around 18 psi boost.

Neil.