Integra Type S K20C8 Engine?

[Azkyrie6]

Was putting away some paperwork and noticed on the sale sheet that the ITS has a slightly different engine: “K20C8”

I assumed that the ITS had the same CTR K20C1 engine

the official engine specs are:
Displacement: 1,996cc - 2.0
Horsepower: 315@6,500rpm - 320@6,500rpm
Torque: 310lbft@2,600-4,000rpm - 310@2,600-4,000rpm
Redline: 7,000rpm - 7,000rpm
Bore and Stroke: 86.00mmx85.9mm - 86.99mm/85.9mm
Compression Ratio: 9.8:1 - 11:0:1???

everything is nearly identical, and only information I can find was HPD’s version of the ITS DE5

Higher engine compression ratio traditionally may yield more torque and horsepower, while increasing the chance of detonation and potential need to switch to a higher octane fuel, our user manual recommends 93 octane (which many of us can’t get in many states)

anyone have more information that can confirm we do have the K20C8 engine? This is something to note for those who might use the type R’s FBO’s and tuning. Could be good to be cautious in case there are differences which would affect your tuning and long term reliability

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[ABPDE5]

K20C8 and K20C1 are mechanically identical. The 8s go to Marysville, and the 1s go to Japan.

The HPD DE5 is not running the same tune, etc. as the stock K20C8 (likely has forged rods, etc. -- note: "developed by HPD and HRC for motorsports use", "Motec M1 ECU...").

 

[optronix]

One of the review vids pointed this out (edit- savagegeese). They are stamped from the factory but also mechanically identical.

(Not my photo, stole it from another post on this forum that stole it from facebook but found via google)

And yes, HPD is a company that builds race cars, so that infographic you found details what they've done that justifies spending $125k on one. The engine in the HPD Type S apparently makes 360HP.

 

[Azkyrie6]

K20C8 and K20C1 are mechanically identical. The 8s go to Marysville, and the 1s go to Japan.

The HPD DE5 is not running the same tune, etc. as the stock K20C8 (likely has forged rods, etc. -- note: "developed by HPD and HRC for motorsports use", "Motec M1 ECU...").

mechanically identical in every aspect as well as compression ratio?

I wonder what’s the point or having C8 and C1. Going back to the Integra DC2 days, the jdm B18C5 engine was different from other B18C engines.

 

[Azkyrie6]

One of the review vids pointed this out (edit- savagegeese). They are stamped from the factory but also mechanically identical.

(Not my photo, stole it from another post on this forum that stole it from facebook but found via google)

And yes, HPD is a company that builds race cars, so that infographic you found details what they've done that justifies spending $125k on one. The engine in the HPD Type S apparently makes 360HP.

360 from other mods or K20C8 engine? Or maybe both were upgraded. At $125k that’s gotta have some substantial performance and handling upgrades wow

 

[ABPDE5]

mechanically identical in every aspect as well as compression ratio?

I wonder what’s the point or having C8 and C1. Going back to the Integra DC2 days, the jdm B18C5 engine was different from other B18C engines.

Yes. The compression ratio is the same ("street" C1 vs C8). You can find the specs in the Acura Integra brochure.

The racing engine is running higher compression.

360 from other mods or K20C8 engine? Or maybe both were upgraded. At $125k that’s gotta have some substantial performance and handling upgrades wow

The sequential transmission and the ECU alone would cost you close to $25k combined.

 

[optronix]

360 from other mods or K20C8 engine? Or maybe both were upgraded. At $125k that’s gotta have some substantial performance and handling upgrades wow

Yeah it's a literal turn-key race car, at $125k it's actually a bargain.

https://hpd.honda.com/Articles/Touring/Integra-Type-S-DE5

I'm not sure what led to the internal decision by Honda to put a different stamp on the engine, but all the media released from Honda/Acura and automotive journalists (who got it from Acura) have all consistently maintained that the engines are mechanically identical. Compression ratio is determined by the amount of volume in the combustion chamber, so the pistons and/or head would have to be completely different for the compression ratio to differ. I haven't personally cracked open the crankcase of an ITS to verify, but I think I'll take their word for it.

What they did change was the software tune- and according to Savagegeese's dyno testing and a few other examples we've seen sprouting around the Internet, the software tune does actually make substantial difference in peak power and how it's delivered- significantly more than 5 horsepower, but it's delivered in a way that is optimized for street driving where the tach needle isn't always pegged near redline, so the Type R does still maintain that advantage for track driving. (I would absolutely love to get my hands on an HPD car, I hope somebody gets one and does a YouTube video soon).

If I recall correctly, the B18C5 was the engine in the Integra Type R. I can't remember full specifics, there are lots of reference material out there but I was never really a "Honda guy" until now- but IIRC it did have a higher compression ratio, upgraded valvetrain, possibly different cams and intake manifold- and I believe the transmission was completely different to with different final drive and an LSD that the other cars with B-series engines didn't get. That isn't the case with the K20C1 vs C8. If Acura is to be believed, you could pull out the engine from an ITS and drop it in a CTR and there would be zero differences.

 

[Azkyrie6]

Yeah it's a literal turn-key race car, at $125k it's actually a bargain.

https://hpd.honda.com/Articles/Touring/Integra-Type-S-DE5

I'm not sure what led to the internal decision by Honda to put a different stamp on the engine, but all the media released from Honda/Acura and automotive journalists (who got it from Acura) have all consistently maintained that the engines are mechanically identical. Compression ratio is determined by the amount of volume in the combustion chamber, so the pistons and/or head would have to be completely different for the compression ratio to differ. I haven't personally cracked open the crankcase of an ITS to verify, but I think I'll take their word for it.

What they did change was the software tune- and according to Savagegeese's dyno testing and a few other examples we've seen sprouting around the Internet, the software tune does actually make substantial difference in peak power and how it's delivered- significantly more than 5 horsepower, but it's delivered in a way that is optimized for street driving where the tach needle isn't always pegged near redline, so the Type R does still maintain that advantage for track driving. (I would absolutely love to get my hands on an HPD car, I hope somebody gets one and does a YouTube video soon).

If I recall correctly, the B18C5 was the engine in the Integra Type R. I can't remember full specifics, there are lots of reference material out there but I was never really a "Honda guy" until now- but IIRC it did have a higher compression ratio, upgraded valvetrain, possibly different cams and intake manifold- and I believe the transmission was completely different to with different final drive and an LSD that the other cars with B-series engines didn't get. That isn't the case with the K20C1 vs C8. If Acura is to be believed, you could pull out the engine from an ITS and drop it in a CTR and there would be zero differences.

Yes. The compression ratio is the same ("street" C1 vs C8). You can find the specs in the Acura Integra brochure.

The racing engine is running higher compression.



The sequential transmission and the ECU alone would cost you close to $25k combined.

incredibly informative. Thank you two. I’m excited to see people add mods and have fun with this car. Should be an extremely capable engine. What will be interesting is if the ITS has any overheating issues the FK8 has and the ~400ftlbs torque limit before the rods and camshafts start having issues

 

[ABPDE5]

incredibly informative. Thank you two. I’m excited to see people add mods and have fun with this car. Should be an extremely capable engine. What will be interesting is if the ITS has any overheating issues the FK8 has and the ~400ftlbs torque limit before the rods and camshafts start having issues

Do the cams have issues related to torque at that point?

I know the rods are definitely the weak point and that the valve train will start to float over 7500 rpm without new springs, but I hadn't heard of cams being an early bottleneck on this motor -- at least not from a reliability standpoint (certainly if you want more power, higher lift is helpful).

 

[Azkyrie6]

Do the cams have issues related to torque at that point?

I know the rods are definitely the weak point and that the valve train will start to float over 7500 rpm without new springs, but I hadn't heard of cams being an early bottleneck on this motor -- at least not from a reliability standpoint (certainly if you want more power, higher lift is helpful).

I don’t know if the cams necessarily fail but once modded in excess of 500hp and 400ftlb there’s a lot of high end power and loss in low end. K20 engines also have VTEC kicking in late as well. VTEC engines you can potentially force the VTEC to cut in at lower RPM, effectively giving you more low end power and better pickup.

for the most part the CTR and ITS already has a good setup with smooth power delivery from low to high end, with the exception that there still some turbo lag but that has been generally okay for FWD cars and limiting wheel spins/hops.

 

[RCX]

Maybe they are tuned at the engine factory and they wanted a way to keep track of them. So C1 vs C8.

So if the C8 makes 320HP with 93 octane, how much less does it make on 91?

And since I am filling up with 94 I guess I get more than 320! That was an easy mod.

 

[Azkyrie6]

Maybe they are tuned at the engine factory and they wanted a way to keep track of them. So C1 vs C8.

So if the C8 makes 320HP with 93 octane, how much less does it make on 91?

And since I am filling up with 94 I guess I get more than 320! That was an easy mod.

I think savagegeese did a dyno running the ITS running 93 octane and was getting 330+HP. Some other reviews like raiti there was mention that the ITS engine makes at least 320hp and “maybe a little bit more”. We do know that it is tuned differently than the CTR with Better timing. If there are any mechanical differences remains to be seen.

there are CTR tunes with more ethanol and race fuel with significant gains but I’d be more interested in hardware mods for consistent and reliable low to midrange gains

 

[ABPDE5]

I think savagegeese did a dyno running the ITS running 93 octane and was getting 330+HP. Some other reviews like raiti there was mention that the ITS engine makes at least 320hp and “maybe a little bit more”. We do know that it is tuned differently than the CTR with Better timing. If there are any mechanical differences remains to be seen.

there are CTR tunes with more ethanol and race fuel with significant gains but I’d be more interested in hardware mods for consistent and reliable low to midrange gains

When Hondata jailbroke the DE5 ECU, they compared it to the FL5. The DE5 gets 2 extra degrees of timing and a slightly higher torque limit.

It seems the DE5 is putting down ~300 hp at the wheels, which is maybe a little more than 10 up on the FL5. Assuming a 15% drivetrain loss, we're probably looking at ~350hp at the crank.

 

[ABPDE5]

Here's the info on the two tunes:

 

[Azkyrie6]

When Hondata jailbroke the DE5 ECU, they compared it to the FL5. The DE5 gets 2 extra degrees of timing and a slightly higher torque limit.

It seems the DE5 is putting down ~300 hp at the wheels, which is maybe a little more than 10 up on the FL5. Assuming a 15% drivetrain loss, we're probably looking at ~350hp at the crank.

That’s quite significant if true. Although we’ve seen the ITS do well in straight line races vs CTR.

here’s an interesting article on upgrading camshaft. I’d be interested in doing this and Ross upgrade before actual bolt ons

https://4pistonracing.com/blogs/news/fl5-civic-type-r-4p-tr2-camshaft-install-and-dyno-test

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