i thought i would pattern this question after Ray's Audi thread. so here is the issue as i see it and have compared two specific hondas in a note that was sent to the BOD and cc:ed the CRB and ITAC (+ K, since he was still listed on the SCCA website).
Please note that Honda's engines and drivelines typically are very similar and part of my question is framed around the fact that the two engines have the same specific output in terms of HP/cc from the factory.
So if they have the same stock HP/cc output, why would they not have similar improvement factors (e.g., the 25% improvement factor or 1.25 x stock HP)
1989 Honda Accord LXi has the following specs per various websites:
1955 CC and 120 HP with a 12 valve head which results in 61.4 HP per Liter.
Given the 17 #/hp target for ITB and 25% assumed HP increase in Improved Touring trim, the Accord should have the following weight per the process:
17 x 1.25 x 120 + 50 (wishbone suspension) - 50 (FWD) = 2550 vs. 2550 in the GCR
Given the 2550 #'s from the calculation and the 2550 in the GCR, it would appear that the winning car from last year's ARRC is at the weight as determined by the process. (please note that i think i used the same basic accord model that won the ARRC).
The 1985-87 CRX Si has the following specs:
1488 CC and 91 HP with a 12 valve head which results in 61.2 HP per Liter
Given the 17 #/hp target for ITB and 25% assumed HP increase in Improved Touring trim, the Accord should have the following weight per the process:
17 x 1.25 x 91 - 50 (FWD) = 1884 vs. 2130 in the GCR
Although both engines are from the same basic vintage and from the same manufacturer and the same specific output in terms of HP per Liter in stock form, the two cars are not treated equally when it comes to power to weight. The CRX Si has a significant weight penalty.
I think the 150 #''s assessed when the 1st gen CRX Si was moved from ITA to ITB was in error and asked to see this addressed.
it is my understanding that specific information (e.g., dyno runs) exist for my vintage of engine that would support something greater than the 25% factor. and here is where i think some have stated that sharing dyno info can only hurt you. for if one builds the accord and shares nothing when it can make improvements similar to other 12 valve hondas with sequential injection, you have a major advantage.
so if the CRB is basing its behind the scenes/behind the ITAC classing on a # per cc displacement basis (note that i am saying IF), and the accord is correctly classed at 1.30 # per cc, the 85-87 crx si would weigh 1941 #'s.
so is there an aero adder for my car? i will admit it is smaller. is there a brake adder for my car? i have not tried to look at brake swept area per #.
it would appear that one way to select a car for a build would be to look at what cars still have the 1.25 multiplier but have engines that are similar to others that have significant higher multipliers. the accord's 1.25 multiplier seems oddly out of place within the honda family of cars in ITA and ITB.
i will gladly admit that my honda experience is pretty much limited to the 1.5/1.6 liter family and the 85 to 2000 crx and civics and not accords. but i have always been impressed with the similar themes and interchangeability of the honda engine families and that is why i do not understand the difference between the accord and crx/civic multipliers given the stock output of the motors being essentially equal in terms of HP per cc.
please educate me.
tia, tom
Please note that Honda's engines and drivelines typically are very similar and part of my question is framed around the fact that the two engines have the same specific output in terms of HP/cc from the factory.
So if they have the same stock HP/cc output, why would they not have similar improvement factors (e.g., the 25% improvement factor or 1.25 x stock HP)
1989 Honda Accord LXi has the following specs per various websites:
1955 CC and 120 HP with a 12 valve head which results in 61.4 HP per Liter.
Given the 17 #/hp target for ITB and 25% assumed HP increase in Improved Touring trim, the Accord should have the following weight per the process:
17 x 1.25 x 120 + 50 (wishbone suspension) - 50 (FWD) = 2550 vs. 2550 in the GCR
Given the 2550 #'s from the calculation and the 2550 in the GCR, it would appear that the winning car from last year's ARRC is at the weight as determined by the process. (please note that i think i used the same basic accord model that won the ARRC).
The 1985-87 CRX Si has the following specs:
1488 CC and 91 HP with a 12 valve head which results in 61.2 HP per Liter
Given the 17 #/hp target for ITB and 25% assumed HP increase in Improved Touring trim, the Accord should have the following weight per the process:
17 x 1.25 x 91 - 50 (FWD) = 1884 vs. 2130 in the GCR
Although both engines are from the same basic vintage and from the same manufacturer and the same specific output in terms of HP per Liter in stock form, the two cars are not treated equally when it comes to power to weight. The CRX Si has a significant weight penalty.
I think the 150 #''s assessed when the 1st gen CRX Si was moved from ITA to ITB was in error and asked to see this addressed.
it is my understanding that specific information (e.g., dyno runs) exist for my vintage of engine that would support something greater than the 25% factor. and here is where i think some have stated that sharing dyno info can only hurt you. for if one builds the accord and shares nothing when it can make improvements similar to other 12 valve hondas with sequential injection, you have a major advantage.
so if the CRB is basing its behind the scenes/behind the ITAC classing on a # per cc displacement basis (note that i am saying IF), and the accord is correctly classed at 1.30 # per cc, the 85-87 crx si would weigh 1941 #'s.
so is there an aero adder for my car? i will admit it is smaller. is there a brake adder for my car? i have not tried to look at brake swept area per #.
it would appear that one way to select a car for a build would be to look at what cars still have the 1.25 multiplier but have engines that are similar to others that have significant higher multipliers. the accord's 1.25 multiplier seems oddly out of place within the honda family of cars in ITA and ITB.
i will gladly admit that my honda experience is pretty much limited to the 1.5/1.6 liter family and the 85 to 2000 crx and civics and not accords. but i have always been impressed with the similar themes and interchangeability of the honda engine families and that is why i do not understand the difference between the accord and crx/civic multipliers given the stock output of the motors being essentially equal in terms of HP per cc.
please educate me.
tia, tom