'09 ALMS Round 8 • Mosport, Aug. 27th - 30th

[Purist]

Careful when talking just about restrictor sizes and engine displacements. A 4.0-litre V8 does NOT have the same performance characteristics as a 4.0-litre Flat-6. The V8s in general make more power down low, and more maximum torque. The sixes come more into their element when they get spooled up, if they're allowed to make power up there with the restrictors they have.

[Francesco]

according to ACO Rules:
"For engines with two valves per cylinder and a single camshaft located in the cylinder block, the following
restrictors’ diameter must be corrected according to the formula:
D = {[D-1] x 1,034} + 1. The result will be rounded to the nearest decimal."

so 2 restrictors @ 1245Kg is 27,7 mm:

27,7 - 1= 26,7

26.7 X 1,034 = 27,6

27,6 + 1 = 28.6mm x 2 restrictors

i am a corvette supporter since they started racing, well, really i started following this kind of racing BECAUSE of Corvettes i loved their battles with prodrive and i have to admit that probably the factories DBR9 were a bit faster at the end of their development! just be fair arakis... Porsche has been granted some "waivers" (as Ferrari was while they where racing the 5 valve F360 ) mainly because their car is just less competitive as a base... at Ferrari the have 2 BIG advantages and the are:
a)mid engine layout
b)rear diffuser

also corvette has some advantages because of the 2 valve engine but that's just to ensure close racing and to make a balanced field, no matter what car you will start with as a "base" - road going car, everybody will have it's own opportunity to DEVELOP a fast, race winning RACE car and that's IMHO a very good thing!

If it wouldn't be this way yeah probably Ferrari would have some great technical advantages but not because they are Ferrari but just because they have a better base to start with, and not Corvette or Porsche which are committed to front and rear engine layout for commercial-historical reasons would probably be interested in competing with a set of rules which doesen't give them the opportunity to race in a competitive way

in the end you would say WHY porsche or corvette or BMW don't make a mid-engine car to compete with the F430? well that's because racing is made to SELL cars not to race cars that you won't sell in a road-going version (altough some people still do so )

[chewymonster]

Originally Posted by JHamilton

When your talking differences in LS engines, your splitting hairs anyway. To say the LS7 and LS7.R are "quite different" is a misnomer. What differentiates each LS engine are the differences in bore and stroke. They all have the same father...

As far as I know the LS7.R was different enough that only Katech could produce it, as in you wouldn't be able to create it out of a stock LS7 engine. Next year it looks like Corvette racing will take a production engine and modify it into a racing engine. This year they are running a race engine made to look like a production engine.

I don't know how similar the Porsche/Ferrari GT2 engines are to their street cars, but I get the impression that they are more closely related than the current Corvette engine.

However, all the top GT2s ran such similar times so obviously the ACO rules work quite well, and ALMS adjustments make the cars even closer in performance.

[arakis]

to Francesco, I apologise i had no idea corvettes had a 2 valve engine!, you are apsolutly right, and i had no idea that 5 valve engines were not alowed

[Francesco]

5 valve engines are/where allowed ferrari just got some "restrictor help" in FIA-GT if i remember correctly...

[arakis]

I am realy impressed now that i found out no performance adjustment were made to the corvette, they are going to be a handful next season.

P.S. could you pm, me if you know on witch season those restrictor changes were made to the 360 thanks

[WMUCarGuy]

Originally Posted by JHamilton

When your talking differences in LS engines, your splitting hairs anyway. To say the LS7 and LS7.R are "quite different" is a misnomer. What differentiates each LS engine are the differences in bore and stroke. They all have the same father...

Whilst the LS7.R has its roots in the LS7 road engine, there's VERY little that remains from the stock engine. I want to say I heard a figure like $100K per engine for the LS7.R. The new 5.5L will be much more affordable and be easier to maintain.

[Jonerz]

My ragtag group of partly named and described and tagged photos from Sunday. I'll put up Saturday's when I have nothing better to do. Pretty tired, can't remember any good stories at this point. Sorry to disappoint. Wish I could have accessed the internet from the track because there were plenty to tell.

I was very impressed with Corvette Racing's form, BMW's continued strength in spite of their DNFs, and though I was disappointed the 45 and 44 cars didn't show better, non-podiums in this muscular GT2 class are still great finishes. It was nice to talk to all of the drivers, didn't have the courage to admit I was a twitter-follower to some, but there is always next year (perhaps Sebring or Petit will bring out the needed courage to admit my lameness).

Chris

[joeb]

Originally Posted by HORNDAWG

Ya, I was hoping that with KSM, Oak Racing, RML and Dyson running the MZR.R that AER would get past this stage, but alas, it's not looking to promising at this point!!





L.P.

I was left shaking my head after this race too.....

[JHamilton]

Originally Posted by chewymonster

As far as I know the LS7.R was different enough that only Katech could produce it, as in you wouldn't be able to create it out of a stock LS7 engine. Next year it looks like Corvette racing will take a production engine and modify it into a racing engine. This year they are running a race engine made to look like a production engine.

I don't know how similar the Porsche/Ferrari GT2 engines are to their street cars, but I get the impression that they are more closely related than the current Corvette engine.

However, all the top GT2s ran such similar times so obviously the ACO rules work quite well, and ALMS adjustments make the cars even closer in performance.

Originally Posted by WMUCarGuy

Whilst the LS7.R has its roots in the LS7 road engine, there's VERY little that remains from the stock engine. I want to say I heard a figure like $100K per engine for the LS7.R. The new 5.5L will be much more affordable and be easier to maintain.

I know about the custom casting and trick heads by Katech. My point is that there is no groundbreaking technology found in the LS7.R versus its street cousins. I maintain that the destroked LS7.R (or the upcoming reduced bore LS3) are as close to production engines as the bored Porsche or destroked Ferrari.

[HORNDAWG]

Originally Posted by JHamilton

I know about the custom casting and trick heads by Katech. My point is that there is no groundbreaking technology found in the LS7.R versus its street cousins. I maintain that the destroked LS7.R (or the upcoming reduced bore LS3) are as close to production engines as the bored Porsche or destroked Ferrari.

I'll second that!!





L.P.

[MJ_N_09]

I see that arakis hasn't stopped while I was gone. Infact, he has found his 2nd marque to pick on, and it happens to be my favorite.

I'm not posting in these race threads anymore if he continues this crap. BTW, I now hope that when it comes, the 458 GTC crashes and burns.

[arakis]

I would appreciate that you at least read my posts before you start your slander.

I did not pick on the corvettes, I thought something witch turned out to be wrong, I was corrected, and apologized for my post that was incorrect.

Let me phrase this a little more clearly, I like the corvettes, and am very impressed by them, and happy for them, and for the gt2 championship!

[MJ_N_09]

In all fairness, I skimmed over your posts because it all seemed to be nothing but bashing the F430 GTC's top competitors. If I see that you actually did apologize, then great.

[Tim Northcutt]

Originally Posted by MJ_N_09

I see that arakis hasn't stopped while I was gone. Infact, he has found his 2nd marque to pick on, and it happens to be my favorite.

I'm not posting in these race threads anymore if he continues this crap. BTW, I now hope that when it comes, the 458 GTC crashes and burns.

Attack the post, not the person posting...

Don't make it personal....

[Jonerz]

Yeah, when there are DRIVERS piloting the 458, try to ease up on references to crashes and burns. Especially with the recent news of a driver passing due to injuries sustained in a fire at a Daytona SCCA event.

Chris

[Bob Riebe]

Originally Posted by chewymonster

As far as I know the LS7.R was different enough that only Katech could produce it, as in you wouldn't be able to create it out of a stock LS7 engine. Next year it looks like Corvette racing will take a production engine and modify it into a racing engine. This year they are running a race engine made to look like a production engine.

I don't know how similar the Porsche/Ferrari GT2 engines are to their street cars, but I get the impression that they are more closely related than the current Corvette engine.

However, all the top GT2s ran such similar times so obviously the ACO rules work quite well, and ALMS adjustments make the cars even closer in performance.

The ONLY thing the Katech engines had that no one else could get were the special restrictor-beater small valve cylinder heads.
ANYTHING else is interchangeble from street to race depending on bore and stroke.
Race teams, often, buy parts in the rough and do most to ALL the machine work themselves.

[Bob Riebe]

Originally Posted by WMUCarGuy

Whilst the LS7.R has its roots in the LS7 road engine, there's VERY little that remains from the stock engine. I want to say I heard a figure like $100K per engine for the LS7.R. The new 5.5L will be much more affordable and be easier to maintain.

I could go to a top engine builder with a block out a street car and have a race engine built out of it; it would be no more or less stock than the Katech engines or any stock-block racing engine.

One hundred thousand per engine is not high, but average, if one wants an engine that gives any team even a CHANCE at being more than a also ran.

[MJ_N_09]

Originally Posted by Jonerz

Yeah, when there are DRIVERS piloting the 458, try to ease up on references to crashes and burns. Especially with the recent news of a driver passing due to injuries sustained in a fire at a Daytona SCCA event.

Chris

err...I got carried away again. I should've said that I hope that it at least disappoints on the track.

[Audi Racer]

Originally Posted by arakis

well the 5.5 l engine with huge 30.2 restrictors helped, they have the biggest engine and the biggest restrictors?

You do realize that the corvette uses E85 Ethanol fule compared to e10 for the other GT2's

[Audi Racer]

Originally Posted by ztnedman1

you.

4 is my perferred vette, and I hate 62. Besides karma has yet to get them back for 2007 sebring.

The 2008 season was an ALMS disaster for Risi. Wasn't it Utha that the car caught fire out in the desert.2007 mid ohio Tomas enge in the petersen white lightning ferrari took the 62 out of the lead. 2007 LeMans 2008 sebring. 2009 st pete 2008 st pete. I could go on and on

[arakis]

Originally Posted by Audi Racer

You do realize that the corvette uses E85 Ethanol fule compared to e10 for the other GT2's

what is the difference performance wise

[Audi Racer]

Originally Posted by arakis

what is the difference performance wise

it seems like their is less energy in a gallon of E85 compared to a gallon if E10. E10 is more explosive

[Francesco]

i'll try to give some sort of explanation

E85 is difficult to manage, more ethanol can lead to biggest "detonations" (... sorry for my english but i am not sure that's the right word for what i want to mean... ) problems which is very bad especially on turbo engines (just look at MZR-R)


E10 meaning that has 10 parts of ethanol and 90 parts of "normal fuel" has less detonation problems but also gives little less horsepower and better fuel economy

E85 with 85 parts of ethanol and 15 parts of fuel has more detonation problems, less fuel efficency but little more horsepower given by the fact that ethanol has more "explosive" power than normal fuel

am i right?

[arakis]

do you by detonation problems mean the fuel is prone to combustion before the spark plug

btw those are two conflicting opinions above