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PostPosted: Mon Dec 16, 2019 8:45 am 
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Greg Amy wrote:
I see the modern Honda 130hp 16-valve DOHC 11.5:1 direct-injection 6800-RPM engine is perfectly acceptable in HProd, yet the legacy Volkswagen 91hp 8-valve pushrod 10.5:1 analog injection 5600-RPM engine is a threat to HP because it is two liters displacement.

They'd actually prefer you first prep the 1.8L 76hp engine to compete against the 91hp 3-valve DOHC Honda (with the Honda being 200# lighter) before they'll consider classifying the +15hp 2L version. So -15% hp and +15% poundage?

Okey doke. Thanks for your reponse.


Everyone seems to notice the 130hp 2015+ Honda Fit, but no one actually seems to know anything about it... Like that is the stock compression ratio, it is one like two cars in H that get no compression increase, so no gain there. The OE cam lift is 0.420, so at 0.425 max not much of an allowance there either - going to have to do it on duration. And at 2250lbs it is one of the heaviest cars in H. Such an over-dog no one has built one.

Hard to bolt on torque, something the VW already has, so it doesn't need to go bigger. The VW guys just need to stop wrecking and breaking. The H VWs typically have the fastest mph at the Runoffs, they don't need more power.

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PostPosted: Mon Dec 16, 2019 9:02 am 
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Jason@SportsCar wrote:
Everyone seems to notice the 130hp 2015+ Honda Fit, but no one actually seems to know anything about it... Like that is the stock compression ratio, it is one like two cars in H that get no compression increase...

Which, as I recall, something like 11.5:1, yes? Far more tha other "limited prep" cars.

And let's not forget that coupled to direct injection. Don't underplay the possibilities there. Are there any otehr DI cars in Prod?

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The OE cam lift is 0.420, so at 0.425 max not much of an allowance there either...

...other than re-developing the cam profiles to take advantage of high-end power instead of fuel economy concerns. Oh, and let's not forget VTEC, to cover any mid-range issues.

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And at 2250lbs it is one of the heaviest cars in H...


Welcome to America's Dyno 2020 where weight really doesn't matter. I'm sure it'll be fun at Daytona too.

(In today's automotive climate, trying hard not to generally snicker at someone called 2250 "heavy". Yes, I know we're talking Prod, but stilll...)

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Such an over-dog no one has built one.

Yet. How long has it been in there? Maybe nobody has noticed (I hadn't). But HProd had good visibility at VIR and there's a lot of people trying to find ways in (witness my request for the 914). Even Ed is looking for a good Fit candidate for Road America.

Be careful what you ask for...


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PostPosted: Mon Dec 16, 2019 9:10 am 
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Greg Amy wrote:
Jason@SportsCar wrote:
Everyone seems to notice the 130hp 2015+ Honda Fit, but no one actually seems to know anything about it... Like that is the stock compression ratio, it is one like two cars in H that get no compression increase...

Which, as I recall, something like 11.5:1, yes? Far more tha other "limited prep" cars.

And let's not forget that coupled to direct injection. Don't underplay the possibilities there. Are there any otehr DI cars in Prod?

Quote:
The OE cam lift is 0.420, so at 0.425 max not much of an allowance there either...

...other than re-developing the cam profiles to take advantage of high-end power instead of fuel economy concerns. Oh, and let's not forget VTEC, to cover any mid-range issues.

Quote:
And at 2250lbs it is one of the heaviest cars in H...


Welcome to America's Dyno 2020 where weight really doesn't matter. I'm sure it'll be fun at Daytona too.

(In today's automotive climate, trying hard not to generally snicker at someone called 2250 "heavy". Yes, I know we're talking Prod, but stilll...)

Quote:
Such an over-dog no one has built one.

Yet. How long has it been in there? Maybe nobody has noticed (I hadn't). But HProd had good visibility at VIR and there's a lot of people trying to find ways in (witness my request for the 914). Even Ed is looking for a good Fit candidate for Road America.

Be careful what you ask for...


11.0:1 is pretty much standard, but there are limited prep 12.0:1 Datsun/Toyota/VWs in there as well.

It has been classed since 2015. The B segment cars don't have the top end, the trap speeds show that, they may have an slippery shape but they still push a lot of air.

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PostPosted: Mon Dec 16, 2019 9:29 am 
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Greg Amy wrote:
chois wrote:
So what power can the 1.8 make at the allowed CR and cam lift?

Dunno, and I'm not gonna spend my money to find out.

The full-prep FProd 1.8L engine I have in the car now (borrowed from Chris Foley because my 2L broke a crankshaft the week before the Labor Day Historics :boohoo:) is around 150 crank, per Chris. That's with big compression (12:1?), big lumpy cam, and a pair of Weber IDFs (GCR sez 38mm chokes). Damn that thing sounds nice at idle...my historics 2L was around 140 crank with 1mm overbore but with big valves, mild hand-porting, mild compression (9.5:1? instead of 10.5:1) and a comparable cam (.435 lift versus LP's .450 limit). And that's with dual 40DRLA Dellortos (38mm venturis). Recall, to be compliant the 1.8L HPLP 914 has to run stock valves and the single stock central-plenum throttle body of 44mm (I think), so that's a totally different induction system and no porting and no big valves (but a little more compression).

I would guess - and it's purely a guess, as I've never done it - that an LP-compliant 2L engine could get 140crank with development. So knock off your general Internet rule of 15% and let's call it 120 wheel.

Rumor has it the 1.5L Hondas are putting out around 130 wheel right now, at a 1900# base weight.

Since the 1.8L 914 in HPLP is currently at +200# over the Honda (IMO too heavy for that engine), I expect that a 2L, if it were classified, would have come in at a very very piggy weight (my chassis as-raced without driver is 1875# dry). But since I'm building a replacement 2L engine for Historics anyway my goal was to develop it to participate in HP and eventually toss real numbers at the PAC to hope for an appropriate adjustment. I would have driven it with ~300 ballast added (but easily removeable) and even if it never got a comp adjustment at least I still have an OK engine.

Instead, I'll develop the EFI for the street car and builid the racer's engine with the same "noncompliant" heads and Dellortos to go play with the vintage crowd. If the situation ever changes I can always use what I learned on the street car for the race car.

Greg


I'll agree that the Fit scares me a bit. At that stock power, with that head, and the allowance to add duration (even at stock lift, let alone .425"), optimize valve train and get the gearing "right" will make it killer.

However, I don't buy that an LP 1.8 914 has no chance. That OEM hp number is with a silly low 7.6 CR, tons of cam development potential, and a plenum manifold that only feeds one hole at a time. Built right, and using a modern ecu, coupled with unquestionably the most ideal layout, lowest CG, likely best braking chassis in the field would not IMO be a knife in a gun fight. Probably not an over-dog out of the box, but I'd expect competitive. More importantly - the risk to the category when the most raced car is Austin Healey, to let one potential 2.0 914 be built seems more likely to be negative. I'd call it conservative, rather than fear of the "big block" 914, but it honestly sounds like you'd rather build the Fit if you were super interested in front running out of the box - manufacturer support, competitive power out of the gate both are big plusses.

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PostPosted: Mon Dec 16, 2019 11:03 am 
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chois wrote:
I'll agree that the Fit scares me a bit. At that stock power, with that head, and the allowance to add duration (even at stock lift, let alone .425"), optimize valve train and get the gearing "right" will make it killer.



Like many of the modern Hondas the L15 has a single exhaust outlet in the head, seems like that could limit its potential. But it sure makes the header build easy.

Image

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PostPosted: Mon Dec 16, 2019 6:09 pm 
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I dont see why H can not add some of the old ITB sub 2.0 litre cars . We simply need to spec line the car with conservative compression and add an extra 100# . No logical reason .
The 914 should come it with 11/1 or maybe 10 .5/1 > regardless we should give it a spec line. IMHO. Take the weight out if the car responds as expected . We should have some IT history to make some assessments.The tiny throttle body should keep it under 6000 RPM.
I requested the BMW 1.8 with the same little tiny throttle body . I still think that they deserve a spec line. No place does it state that they need to be 12/ 1.
Maybe the 1.9 - 2.0 litre can be speced at 10/1 .

The Hondas continue to exceed expectations. Nothing way out of range . Simply the sweet balance of light weight on the nose allowing great lateral power, enough power to compete on the straights, and they dont break.

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