audi engine max rpm

Eric · 10-28-06, 09:42 PM

since the audi transmission is so popular in the gt40 replicas, i'll assume the engine is used as well. i've been comparing audi's 4.2L v8 to their 6.0L w12. the chassis that i designed can fit both, and they both have the power output i want, but i don't know the maximum rpm of each. i think i heard that the v8 goes up to 8250, but what about the w12? i want the car i'm designing to be able to hit 200mph, but the engine needs to hit at least 7200 rpm for that to be possible with a porsche g50 transmission (and don't tell me to use the audi transmission with it, the ratio for first gear is terrible in all audi's gearboxes).

Lynn · 10-28-06, 10:57 PM

Actually, I know of NO Audi powered GT40s. The Audi transaxle is used in conjunction with a Ford push rod V8* in virtually all cases. The transaxle from the Audi 5000 just happens to be one of the handful of transaxles that lends itself well to use in a GT40 replicar.

*The new Ford mod motor has been used in a few cases, but the width of the engine across the "shoulders" is large enough to make its use problematic in most GT40 replicas.

Regards,
Lynn

Peter D · 10-29-06, 07:40 AM

This one is in Oz - more than a year ago. No idea of whose it is, or any progress - it is a BIG engine !

Kind Regards,

Peter D.

Eric · 10-30-06, 11:40 PM

i'm well aware of how big both engines are. i planned for them both to be able to fit the chassis. all i want to know is can the w12 hit 7200? i've seen both the audi a8l and the bentley continental gt that it is in show the rpm up to 8000, but i haven't seen either hit that due to the transmission timing.

Ron Earp · 10-31-06, 08:12 AM

I'm sure both motors will physically turn 8000 RPM+ and live. But if there are limiters in the software for the transmission or engine, then of course they will need to be removed.

You might want to try this question on Welcome to AudiWorld.com - The Audi Enthusiast Website. They have an active forum community and I bet some of the folks there would be able to tell you for sure.

J. Salmon · 11-01-06, 11:00 AM

I had an S4 with the V8. If I remember correctly, the max rpm was about 7500, and chip tuners would take that to 7800. The 8250 rpm motor is from the new RS4, and it has significant internal improvements to allow for the increased revs (including a variable limiter that will not allow max rpms until the oil temp is up). I imagine it would be a rare and very expensive motor. I have seen S4 motors for less than 10k used, but new they are not cheap.

I also have wondered about the use of the W12 (in a P3 replica - you gotta have a 12 there for the sound). The motor has peak power at 6800 rpm. I would doubt it spins much over 7200 in stock form, though you might be able to push it harder. But your power (not very much if 200 mph is your goal) is going to be dropping off. Not sure the price on that one, but again I would think it is not cheap.

Both motors have very integrated ECU's that will not be amenable to use by a newbie such as me. I cannot fathom a wire diet on an audi electrical system.

And I am glad that I get a bit spooked at 140 mph. Makes life much easier.

I LOVE GT40- Paolo · 11-01-06, 01:35 PM

Maybe I can be wrong...but...isnt maybe such BIG engine a problem in the distribution of weights over the car?.
From the few I know about race cars the engine should be the smallest one and in the more central lower point available.
That one seems just giant (I like that indeed) and seems in another scale than the gt body.

Paolo

J. Salmon · 11-01-06, 08:13 PM

Quote:

Originally Posted by kenshiro8

Maybe I can be wrong...but...isnt maybe such BIG engine a problem in the distribution of weights over the car?.
From the few I know about race cars the engine should be the smallest one and in the more central lower point available.
That one seems just giant (I like that indeed) and seems in another scale than the gt body.

Paolo

I agree, though I guess the weight is more important than the size (I think modular 4.6 Ford motors are about the same weight as a typical 302, but much bigger). I think it would be a silly to use the V8 when (1) it doesn't make as much power as the 302, (2) it isn't the right look and (3) it would be much, much more difficult.

But if you really wanted a 12, the W12 would be as good a choice as any, since there aren't that many choices. Course it wouldn't look right either.

Ron Earp · 11-01-06, 09:49 PM

Bigger and heavier. Mod motor is all aluminum in lighest configuration, and is not as light as an all aluminum small block. Ditto the iron block/ally head mod, it is heavier than the iron block ally head SB. All those cams, valves, chain, EFI, etc. add up. Plus, you gotta count that blower in place on the mod motor to make it produce some real power...

Scott Calabro · 11-01-06, 10:47 PM

Westie .... In the end its all up to your pocket book. Trying to "work" a motor like a w12 would be difficult and way expensive at best. Plus it won't sound like or look like the thing we all love. Although with enough cash anything in the automotive world is possible. If I may, here is my recipe for the most bitchin' of 40 motors......
1) 8.2" Deck height Dart alum SBF (cyl decks@ "0")
2) Custom 5.6" alum con rods by Howards Rods..1.866 R/S ratio !!!
3) Mahle pro series 2618 1.090 comp height slugs
4) Crower "cup" 3 inch stroke crank
5) Comp solid roller 252 x 260 x .672" @ 106 lobe sep
6) AFR 205 cc heads with chambers cc'd to 11.5 to 1 C/R
7) Jesel shaft rockers
8) Vertex magneto ignition
9) Four Webers
10) Canton alum road race pan with windage screen and Accusump
11) 1.75 " 180 deg headers
12) 15lb Alum flywheel
It would be a handful in traffic but you would ahead of them most of the time anyway!!!!

Eric · 11-03-06, 05:37 PM

i have no intention of it looking our sounding like an american car. the design basis is purely european.

weight distribution? it's a mid engine setup i designed with a 105" wheelbase, so i think it will be fine with the suspension i designed. plus all of the chassis is aluminum apart from the steel roll cage. so total weight won't be much, hopefully working with low air resistance for high speeds.

ah and price. in first building the car (which will be expensive with casting the body, glass, and all) i planned on first using the v8. the w12 would be installed when i could acquire one in decent condition. and i was thinking of shoving two turbos in the engine bay with that engine...

Doug Sainlar · 11-03-06, 06:06 PM

Quote:

Originally Posted by salmjo1

And I am glad that I get a bit spooked at 140 mph. Makes life much easier.

I agree with this statement--I'd just like to get there in 3.6 seconds or less.

Dugly

Scott Calabro · 11-03-06, 08:43 PM

To each his own.

marc · 12-29-06, 11:59 PM

Newbie to the GT40s.

I have a Corvette ZR1, 350CI DOHC 32v 7200 rpm 400hp motor. wicked fast and torque curve so long and flat. I was hoping to use one of these in my upcoming project but the damn thing weighs as much as a big block. Great sound though, very deep in the normal range, but step on it and she screams like a banshee.