Carb Selection

John Fitzpatrick said:
We're suckers for massive engines, as though quarter mile times were what a GT-40 is about. In our heart of hearts we know a 5% increase in horsepower is barely noticeable, but "bolting on" 50 HP is ever so much less tedious than fine tuning the suspension. I know I've spent MUCH more time tweaking my Webers than I have fretting about my front end geometry.

I agree completely John...as we all know, the only function of the chassis is to hold the engine up off the ground!

Seriously, this is an attitude that I see or hear almost every day in one customer or another (surprisingly, it's not always the amateur guys either). Makes me wonder sometimes how they have any success in motorsports at all.
 
Ron Earp said:
<snip>
But, bear in mind this thread was just about getting a proper carb on a high revving V8, not getting every hp from the engine.
<snip>
Ron- My apologies --I didn't intend to take the thread off-topic, and certainly not to belittle the importance of getting the most useable horsepower from your engine. Learning is a big part of the enjoyment of this, and someday it might be critical to know how to get that last 1%. My thought was to keep the power aspect of total performance in perspective, not to malign the inveterate engine tuners among us!
 

Ron Earp

Admin
No no, you are right on. I just didn't want folks to think I was out for 50hp over other development. Just out for a good carb. I truly feel that 250-350hp in a GT40, Lola, or whatever will be plenty (at 2000-2200lbs) for most drivers, and that includes me for sure. Like you, I think that going for the chassis development and driving is key and much more important.

So keep posting your thoughts, you aren't disturbing me and sorry if I came off that way. Your comments on laptimes are spot on and I see that every week at the track. I routinely see 115 rwhp cars, those pesky Miatas again, do the business on 300-500hp "Supercars" at VIR and other tracks. In fact, not sure what a GT40 would have ran on the VIR Full Course, but spec Miatas are down to 2:18s. I plan to take one of ours up for a BMW club day here shortly. It is fun to see the M3/M5/Corvette owners get frustrated at the Miatas.

Development and learning to drive what you have to the max is the way to go.

Ron
 
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Development and learing

Ron,
I have just done a day at one of our GP circuits in Oz in a 40 and I can tell you your statement "Development and learning to the max is the way to go" is never so true.
There were a few Lotus Elise there with supercharged Honda Integra engines pushing 280HP at 9000RPM and at 700kg dont even think about it.They were lapping as quick as GP cars - were road registered and driven to the circuit.
The 40 was fun but farrrr tooo tailey for my liking.Straight line HP speed and let it rip.Tight corners .Nup.Cheers and enjoy the Lola.
 
sorry to continue the journey off topic...

Ron Earp said:
It is fun to see the M3/M5/Corvette owners get frustrated at the Miatas.

Ron, I second this. There is nothing more fun than beating a high dollar guy with a low dollar car. My best non-racing experience was at a Porsche club track day with my wife's dead stock (Michelen MXV4 tires!!) Prelude. My wife heard one spectator say, "That must be one of those turbo, all wheel drive Preludes."

My racing experience is all with low power cars (sub 150hp) and in competition, I'll take horsepower over handling any day. The reason? Someone with more power and less skill can pass me and hold me up in the corners, even if we run similar total lap times. Better handling just moves me further up the grid with cars with more power and makes the racing very frustrating! Still, my engine is legal to the letter for ITA, and I'm not willing to cheat to go faster.

I think 17 years of being passed on the straights by jokers who can't drive has caused me to try to be sure that doesn't happen very often in my GT40! I'll diverge from the group opinion and say give me that extra 50hp!

I have to say that I really appreciated that old webber flow discussion you started. I have racing experiece with EFI and Webbers, and I'm going EFI on the GT40. Between the flow limitations and MAP fluctuation, I'm going with sequential EFI with a 4bbl-style throttle body on mine.

"There is no such thing as too much power, there is only too little skill."

Garrett
 

Russ Noble

GT40s Supporter
Lifetime Supporter
I agree with you whole heartedly Garrett. You can never have enough power. For times when it is not possible to use it you lift your right foot, that's why God gave us right feet, to restrict the power of the motor! Most guys have got it figured the wrong way round. They think its an accelerator, it's not, it's a throttle. You can build as much power into your motor as you like, but you don't have to (can't) use it all the time.

But in saying that, a well sorted chassis and brakes will go a long way to overcoming a horsepower deficit. However if you sort your chassis etc with a low power motor and then upgrade to something substantially more powerful, you'll have to start all over again on the handling setup.

Just my 2c.

Regards
 
Ron Earp said:
I truly feel that 250-350hp in a GT40, Lola, or whatever will be plenty (at 2000-2200lbs) for most drivers, and that includes me for sure.

You have a stroker motor with custom ported AFR 185 heads, and a solid lift cam at a near 700 lift! That combo is an easy 500hp maybe more depending on your compression. So if you are only looking for 350hp save yourself the money and just pick up an off the shelf 750 dp from summit and you will still surpass your 350hp goal (by a long shot)
 

Ron Earp

Admin
That is my old GT40 motor. We're going to use it to quickly get running, but I think we'll replace it with a much milder motor and yank it out. Right now I have the classic disease, mahfundsarelow, so I can't get another motor to put in the car.
 
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