For the 'natural aspirators' - How tuned is your engine?
Discussion
M11 MFP said:
Ok, I raise you 1997 IES/Judd nissan primera BTCC 
. 88mm bore, 310 or 320hp, depending on who you believe.
score 1032 - 1066
http://www.marklamond.co.uk/misc/scans/CCC_1999_Fe...
About as far from a road car as it gets, however.
Having read the scanned document I believe the claim of 200bl/ft from a 2 litre is a little optimistic. Better specific torque than F1 engine.. 88mm bore, 310 or 320hp, depending on who you believe.score 1032 - 1066
http://www.marklamond.co.uk/misc/scans/CCC_1999_Fe...
About as far from a road car as it gets, however.
[pic/]http://img117.imageshack.us/img117/5720/torquehk8.png[pic]
310Nm or 223 lb/ft from 2.4 litre 92.9lb/ft litre
My standard sized 4 litre Speed Six makes 443 bhp - what does that mean with these numbers?
Finally got to a PC. 826. Nice!
Actually, that manages to beat the 458. Very nice... Anyone want to check my figures (I'm terrible at this stuff). 4 litre Speed Six, 96mm bore, 443bhp.
Finally got to a PC. 826. Nice!
Actually, that manages to beat the 458. Very nice... Anyone want to check my figures (I'm terrible at this stuff). 4 litre Speed Six, 96mm bore, 443bhp.
Edited by Don1 on Sunday 13th October 18:33
Kozy said:
C.A.R. said:
Unfortunately for me extortionate rent and other bills have forced me into a dull old diesel, but the old 2ZZ-GE engine in the Celica I used to drive had an 82mm bore and gave 189bhp - scoring an impressive 725 on your calculator.
Those engines appear to be extremely under-rated!Why oh why did they not put that VVTLi system in the GT86!!
Cracking engines. 8300rpm on the second cam is a thrilling experience. Place it in the kart like handling chassis of an Elise 111R, or Celica T190 and they are wonderful fun. Amazing value in the Celica T190 too. Easier to live with than a DC2 anyway. Now the ratio of 725 v the cost of a Celica T190 (£3-4k for a real minter) is good value!
Interestingly, the old RAC (taxable) horsepower was calculated in a similar manner -
RAC hp = bore^2 x cyl / 2.5, with bore in inches.
= bore(mm) ^ 2 / 1612.9
RAC hp = bore^2 x 0.62 x 10^-3
Kozy max hp = bore^2 x 9.694 x 10^-3
So in 1910, the RAC assumed a PI of 64, if my maths is correct
RAC hp = bore^2 x cyl / 2.5, with bore in inches.
= bore(mm) ^ 2 / 1612.9
RAC hp = bore^2 x 0.62 x 10^-3
Kozy max hp = bore^2 x 9.694 x 10^-3
So in 1910, the RAC assumed a PI of 64, if my maths is correct
Edited by AW111 on Sunday 13th October 14:55
X959 said:
JDM B18C Type R Integra
81mm bore, 197bhp Standard.
Should be running about 215-220 now with some breathing mods so a PI of between 845 and 865.
You expect to gain 12% from some breathing mods? You're probably at about 202BHP, max. Unless you've put new cams on it and have a complete straight-through exhaust system, you're not getting 220BHP. 81mm bore, 197bhp Standard.
Should be running about 215-220 now with some breathing mods so a PI of between 845 and 865.
Interesting article. Maths follows the logic, but I'd want to check your constants more closely.
FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
havoc said:
Interesting article. Maths follows the logic, but I'd want to check your constants more closely.
FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
A V6 revving to 9700rpm? Doesn't sound too ridiculous.FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
GroundEffect said:
X959 said:
JDM B18C Type R Integra
81mm bore, 197bhp Standard.
Should be running about 215-220 now with some breathing mods so a PI of between 845 and 865.
You expect to gain 12% from some breathing mods? You're probably at about 202BHP, max. Unless you've put new cams on it and have a complete straight-through exhaust system, you're not getting 220BHP. 81mm bore, 197bhp Standard.
Should be running about 215-220 now with some breathing mods so a PI of between 845 and 865.
I was told these engines respond really well to breathing mods and to expect these figures. If it's wrong then I accept that, but that's what I have been told.
Edit: Stage 3 Package Up to 15BHP
Stage 2 + Exhaust manifold + Decat From £1145 + vat
The stage 3 tuning package for your DC2 concentrates on further improving flow through the engine in order to increase its volumetric efficiency, allowing even greater power gains. To do this we concentrate on freeing up the exhaust path using DC sports products, which provide similar gains to TODA systems, but offering much greater value for money.
Taken from this website: http://www.euro-spec2000.co.uk/Tuning/Honda/integr...
Everything in that package has been done to mine, plus the cold air feed. It doesn't mention the diameter of the exhaust but mine is 2.5", so I assume the same size as that in the package mentioned, so I don't think expecting to gain between 15 and 20 bhp on a well maintained, low mileage engine is overly too much to expect.
Its hard to make your tone come across in writing but I'm not trying to argue or anything and i'm happy to be educated or the subject
Edited by X959 on Sunday 13th October 15:31
havoc said:
Interesting article. Maths follows the logic, but I'd want to check your constants more closely.
FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
Yes, that's correct. 76mm vs 86mm stroke, big difference in piston speeds with the V6s shorter stroke allowing much higher speeds.FD2-R engine, as standard (86x86 I-4), 774PI - and the factory redline is REALLY close to your theoretical max-rpm of 8,700+
NA1 NSX, as standard (oversquare 90x76 V6), 577PI - but a theoretical 9,700rpm!
I think the reality is closer to GEs idea, sorry chap.
The UKDM DC2s (2.25" exhaust) benefit quite a bit from the 2.5" JDM exhaust system, but beyond that you don't get very far...so a JDM car MAY see 10-12bhp from a very good full exhaust swap (typically a peaky 4-1 system rather than a broader 4-2-1), but more likely you'll realise 6-8bhp from a decat and a fully mandrel-bent system.
Re: induction, I think the consensus is that the standard airbox is about as good as it gets...any benefits there are marginal.
For a JDM to get above ~210bhp you need hotter cams, regardless of what the tuners want you to believe. With those, it's possible to get a B18 up to c.230bhp, maybe 240bhp if you're happy to have an even-peakier engine which needs regular TLC. Beyond that needs FI.
Oh - one thing - the DC2s limiter (c.8,700) is about bang-on what the OP's calcs say is possible reliably (8,621). And the engine can clearly do it for >>100k miles without any trouble!
The UKDM DC2s (2.25" exhaust) benefit quite a bit from the 2.5" JDM exhaust system, but beyond that you don't get very far...so a JDM car MAY see 10-12bhp from a very good full exhaust swap (typically a peaky 4-1 system rather than a broader 4-2-1), but more likely you'll realise 6-8bhp from a decat and a fully mandrel-bent system.
Re: induction, I think the consensus is that the standard airbox is about as good as it gets...any benefits there are marginal.
For a JDM to get above ~210bhp you need hotter cams, regardless of what the tuners want you to believe. With those, it's possible to get a B18 up to c.230bhp, maybe 240bhp if you're happy to have an even-peakier engine which needs regular TLC. Beyond that needs FI.
Oh - one thing - the DC2s limiter (c.8,700) is about bang-on what the OP's calcs say is possible reliably (8,621). And the engine can clearly do it for >>100k miles without any trouble!
AW111 said:
Interestingly, the old RAC (taxable) horsepower was calculated in a similar manner -
RAC hp = bore^2 x cyl / 2.5, with bore in inches.
= bore(mm) ^ 2 / 1612.9
RAC hp = bore^2 x 0.62 x 10^-3
Kozy max hp = bore^2 x 9.694 x 10^-3
So in 1910, the RAC assumed a PI of 64, if my maths is correct
Interesting... What was this calculation used for? RAC hp = bore^2 x cyl / 2.5, with bore in inches.
= bore(mm) ^ 2 / 1612.9
RAC hp = bore^2 x 0.62 x 10^-3
Kozy max hp = bore^2 x 9.694 x 10^-3
So in 1910, the RAC assumed a PI of 64, if my maths is correct
Edited by AW111 on Sunday 13th October 14:55
havoc said:
Oh - one thing - the DC2s limiter (c.8,700) is about bang-on what the OP's calcs say is possible reliably (8,621). And the engine can clearly do it for >>100k miles without any trouble!
The early B18s are known for piston speeds exceeding F1 levels at redline. AFAIK the later ones were lowered to an 8400rpm though? The B16B was 8600 with a theoretical limit of 9600, and they are proven to be a longer lasting engine than the B18C, most of which will burning at least a bit of oil and could do with a refresh by now.havoc said:
I think the reality is closer to GEs idea, sorry chap.
The UKDM DC2s (2.25" exhaust) benefit quite a bit from the 2.5" JDM exhaust system, but beyond that you don't get very far...so a JDM car MAY see 10-12bhp from a very good full exhaust swap (typically a peaky 4-1 system rather than a broader 4-2-1), but more likely you'll realise 6-8bhp from a decat and a fully mandrel-bent system.
Re: induction, I think the consensus is that the standard airbox is about as good as it gets...any benefits there are marginal.
For a JDM to get above ~210bhp you need hotter cams, regardless of what the tuners want you to believe. With those, it's possible to get a B18 up to c.230bhp, maybe 240bhp if you're happy to have an even-peakier engine which needs regular TLC. Beyond that needs FI.
Oh - one thing - the DC2s limiter (c.8,700) is about bang-on what the OP's calcs say is possible reliably (8,621). And the engine can clearly do it for >>100k miles without any trouble!
Thanks for taking the time to write that up.The UKDM DC2s (2.25" exhaust) benefit quite a bit from the 2.5" JDM exhaust system, but beyond that you don't get very far...so a JDM car MAY see 10-12bhp from a very good full exhaust swap (typically a peaky 4-1 system rather than a broader 4-2-1), but more likely you'll realise 6-8bhp from a decat and a fully mandrel-bent system.
Re: induction, I think the consensus is that the standard airbox is about as good as it gets...any benefits there are marginal.
For a JDM to get above ~210bhp you need hotter cams, regardless of what the tuners want you to believe. With those, it's possible to get a B18 up to c.230bhp, maybe 240bhp if you're happy to have an even-peakier engine which needs regular TLC. Beyond that needs FI.
Oh - one thing - the DC2s limiter (c.8,700) is about bang-on what the OP's calcs say is possible reliably (8,621). And the engine can clearly do it for >>100k miles without any trouble!
Quick question after reading that then, so mine has the 2.5" 4-1 manifold and full 2.5" system with decat. If the standard airbox is that good then the expected gains from the induction side can be pretty much disregarded, so expected power as it stands should be c.210?
The ecu remains untouched so the limiter is still at the standard point and I haven't fitted a vtec controller. After reading up on them, they just seem to make the vtec come in earlier and make more noise without any real benefit.
The power delivery certainly seems peaky, but I can't compare to a standard one having never driven one.
And if it makes any difference it is a genuine JDM B18C Type R, and not a UK spec B18C6.
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