I read an interesting post on here about horsepower and torque in relation to the driving experience of the GT40. It made me think about top speeds, gear ratios, weight/power ratios and such. Members said things about too much torque can affect the smoothness of the powerband in the GT40, and it is probably silly to desire 600+ horsepower for a GT40 as it makes the driving experience a very thought-intensive process, and that further specified driving instruction would probably be necessary. I think that may go without saying. But could the same be said for other supercars that can go in the 200mph range, especially production cars? Like for example, a 2003 Viper, a Lambo Murcielago, and so on. I mean, I was driving around and I heard that awesome 500hp V10 go by me once at around 30mph and the driver looked relaxed and joyful (what do you expect? /ubbthreads/images/graemlins/grin.gif) I guess I imagine replacing that Viper with a 600hp GT40 and wondering if the driver would be looking like the incredible Hulk in the stop and go traffic. I mean, if I had a GT40, I might go over 100mph once and a while (not often for the sake of my life), but most of my time would be spent just driving around to places like I do nowadays in my Corolla, and just being grateful overall. And if I had one, I probably ram a 600+hp 347 stroker in the back whilst doing this everyday driving. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif Well, it would be nice to hear opinions on this, and thanks for reading my massive post if you did. A have a nice day. /ubbthreads/images/graemlins/wink.gif
Horsepower
- Thread starter LeGT40Mans
- Start date
On the street I have found that these are much more enjoyable if they are geared way down. At LeMans my car ran with a 2.50/1 rear which gave it a speed of 223 at 6400rpm.
On the street I use a 4.56/1 rear which gives it real grunt between 40-80 (passing range) and still enables it to cruise on the highway. (It's top speed is lower but on the street except in Montana where I rarely drive this is not an issue). This also keeps the revs up in traffic which keeps the battery up, the fans going, and the water flowing.
On the street I think a lower flater torque curve is the way to go.
On the street I use a 4.56/1 rear which gives it real grunt between 40-80 (passing range) and still enables it to cruise on the highway. (It's top speed is lower but on the street except in Montana where I rarely drive this is not an issue). This also keeps the revs up in traffic which keeps the battery up, the fans going, and the water flowing.
On the street I think a lower flater torque curve is the way to go.
223mph! That is awesome! This correlates with your post Mark-IV J6: what is the relation between horsepower and gear ratios, and what is required to make a car that can go 200+ at least a somewhat enjoyable experience on the street? You mentioned that it is more enjoyable when "they are geared down." Would you, or someone else, be so kind as to explain this concept (I will also do a search on the forum). Thanks again!
223mph. . .Mark IV. . .WEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/laugh.gif!!
223mph. . .Mark IV. . .WEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/laugh.gif!!
You'd be lucky to get 600HP out of a 347, let alone drive it on the road. You are talking about mad numbers here, you'd also need to find a gearbox that would take that power. I'm guessing here but in the US you'd be looking at least $30,000 for the engine and gearbox alone!! The cam neeeded to generate that power from a 347 would make it practically impossible to drive on the road.
A better option would be to go for a 427ci or a stroked 351ci. You'll probably find there are plenty of Cobras pushing that power from 427's, but not a 347.
Regards,
J.P
A better option would be to go for a 427ci or a stroked 351ci. You'll probably find there are plenty of Cobras pushing that power from 427's, but not a 347.
Regards,
J.P
JP
The problem would remain: Trans.
A true USABLE 200MPH street car would be very, very hard to do. Except for a tweaked P GT2 I'm not sure there is one. I'm talking about a car you could drive every day anywhere.
With the gearing I'm now using I doubt my car would reach more than 170. (That so far has been enough for me)
The problem would remain: Trans.
A true USABLE 200MPH street car would be very, very hard to do. Except for a tweaked P GT2 I'm not sure there is one. I'm talking about a car you could drive every day anywhere.
With the gearing I'm now using I doubt my car would reach more than 170. (That so far has been enough for me)
Ron Earp
Admin
JP,
That is not completely astronomical from a 347. There are 302s that make 600 dyno verified hp @ 7800 RPM for around 8-10k, in the US. I posted a link to a company that was doing them maybe a year ago. No, they won't be a pleasure on the street, but they have reasonably low torque so they aren't so hard on boxes. I think it much better to get that power from a stroked motor, like the 427 W. In fact there are a few of those over on Club Cobra making a nice 550-625 without being unstreetable. There are a bunch of 342-347s making 450-500 which are reasonably streetable. But, if you really want 500+ the Windsor strokers appear to be the way to go. We're lucky in one respect - we don't pay a fortune for Ford/Chevy motors, parts, etc. here in the US.
Ron
That is not completely astronomical from a 347. There are 302s that make 600 dyno verified hp @ 7800 RPM for around 8-10k, in the US. I posted a link to a company that was doing them maybe a year ago. No, they won't be a pleasure on the street, but they have reasonably low torque so they aren't so hard on boxes. I think it much better to get that power from a stroked motor, like the 427 W. In fact there are a few of those over on Club Cobra making a nice 550-625 without being unstreetable. There are a bunch of 342-347s making 450-500 which are reasonably streetable. But, if you really want 500+ the Windsor strokers appear to be the way to go. We're lucky in one respect - we don't pay a fortune for Ford/Chevy motors, parts, etc. here in the US.
Ron
Some things to consider:
The GT40 weighs about 1000 lbs less than the Viper and
Murcielago. That's one reason why 600HP in a GT40
makes it a more thought intensive process than those
two.
Ron is correct, it might take about $10K to get 600HP,
but JP is right too - throw another $15K - $20K for
a transaxle that can handle that power well (we're talking
heavily modified G50/52, Hewland, RBT/ZF, etc.) and you're
pretty much staring $30K in the face.
The real issue is - why do you want 600HP? Many of the
guys here will tell you that 400-450HP is more than
sufficient, especially if you hve good power and torque
curves. Again, the right transaxle will make all the
difference. Rick Merz hits consistent 11s in his GTD, and
figures his top speed to be ~220MPH and 0-60 in 4 sec.
Isn't that sufficient?
Ian
The GT40 weighs about 1000 lbs less than the Viper and
Murcielago. That's one reason why 600HP in a GT40
makes it a more thought intensive process than those
two.
Ron is correct, it might take about $10K to get 600HP,
but JP is right too - throw another $15K - $20K for
a transaxle that can handle that power well (we're talking
heavily modified G50/52, Hewland, RBT/ZF, etc.) and you're
pretty much staring $30K in the face.
The real issue is - why do you want 600HP? Many of the
guys here will tell you that 400-450HP is more than
sufficient, especially if you hve good power and torque
curves. Again, the right transaxle will make all the
difference. Rick Merz hits consistent 11s in his GTD, and
figures his top speed to be ~220MPH and 0-60 in 4 sec.
Isn't that sufficient?
Ian
The July issue of Car Craft Magazine had a build up of what I think would be a very good engine for a street driven 40. They used a stock 302 short (1991). the short block was feshened and even retained the stock cam. There were a few tests with stock heads and such, but the test that got to me was with AFR 165 heads and 1.7 pushrod adjustable rockers. The specs were 405 HP at 6200 RPM and 380 lb-ft of torque at 4300RPM. With that stock 5.0 Mustang cam, I am sure this would be a pleasant combo to street drive.
VIC
CAV 40 /ubbthreads/images/graemlins/cool.gif
VIC
CAV 40 /ubbthreads/images/graemlins/cool.gif
I feel that the best way to get big horsepower along with street manners is with a twin turbo setup. Even a stroked 351 Windsor will need a pretty lumpy cam to make much more than 500 hp. With a twin turbo setup, you can make great power (with good flowing heads) with a very mild cam. I know of a 10-second TT Mustang that is a true daily driver. Of course, a TT small block V8 would make gobs of torque and it would need a very strong gearbox and thermal management is likely to be an issue. In the unlikely event I ever find myself flush with cash and bored with ~450 naturally aspirated horsepower this is the route I would most likely take.
All it takes is money...how fast do you want to go?
All it takes is money...how fast do you want to go?
[ QUOTE ]
Some things to consider:
Rick Merz hits consistent 11s in his GTD, and
figures his top speed to be ~220MPH and 0-60 in 4 sec.
Isn't that sufficient?
Ian
[/ QUOTE ]
I believe Ricks car showed 450 HP at the rear wheels which would translate to ~530 - 560 at the flywheel. He never complains about having too much, but he enjoys a good bit of track time, etc. I think it is all in what you plan to do with the car, etc (e.g. street cruising vs. racing or high speed track time).
Some things to consider:
Rick Merz hits consistent 11s in his GTD, and
figures his top speed to be ~220MPH and 0-60 in 4 sec.
Isn't that sufficient?
Ian
[/ QUOTE ]
I believe Ricks car showed 450 HP at the rear wheels which would translate to ~530 - 560 at the flywheel. He never complains about having too much, but he enjoys a good bit of track time, etc. I think it is all in what you plan to do with the car, etc (e.g. street cruising vs. racing or high speed track time).
Perhaps Gordon Levy would like to chime in here. He builds a 306 making around 450hp and 7500 rpm. I am unsure of the torque curve and how streetable these 306s are (don't know much about them).
Hersh has a 306 in his 40 but I believe it makes only 350hp.
I would like to know Gordon's views on a twin turbo 306! Is there room in the RF for this set up?
How about the heat from a TT?
Hersh has a 306 in his 40 but I believe it makes only 350hp.
I would like to know Gordon's views on a twin turbo 306! Is there room in the RF for this set up?
How about the heat from a TT?
All,
You can make 720 HP from a 351 stroked to 401 if you have the right parts. Here is a picture of the motor going in my Daytona. I am going to do the same motor in my GT40 except I plan on destroking it to 320 CI. The GT40 motor will have a 3.00 IN stroke by 4.125 IN bore. The Daytona motor is 3.75 by 4.125.
You can make 720 HP from a 351 stroked to 401 if you have the right parts. Here is a picture of the motor going in my Daytona. I am going to do the same motor in my GT40 except I plan on destroking it to 320 CI. The GT40 motor will have a 3.00 IN stroke by 4.125 IN bore. The Daytona motor is 3.75 by 4.125.
I'll be at Roush Performance Friday to order a 351 based 402" Stroker, 525 hp, 2 year 24k mile warr.! It's for a customer down here in Florida that got tired of spending $15,000 every time he took his F40 in for service! He sold the F40 and has ordered a Gulf widebody CAV from me.
Naturally it will be mated to a ZF. I'll keep you all updated on the project if you want.
Naturally it will be mated to a ZF. I'll keep you all updated on the project if you want.
Richard
Love the piccy of your engine. You may have an issue getting those tubes in under the rear screen even if you take advantage of the dry sump and lower the engine drastically.
JP, there is a production car that was originally purely designed for the road and has 600 bhp, weighs about 1 ton and has boot space for the golf bag plus comfortable seating for two passengers. McLaren F1. Yes please!
Malcolm
Love the piccy of your engine. You may have an issue getting those tubes in under the rear screen even if you take advantage of the dry sump and lower the engine drastically.
JP, there is a production car that was originally purely designed for the road and has 600 bhp, weighs about 1 ton and has boot space for the golf bag plus comfortable seating for two passengers. McLaren F1. Yes please!
Malcolm
It may be the best route to having a tractable engine and the horsepower figures you require (when you want them) by fitting a NOS system! Has anyone considered this option on a GT40?
It worked for a clapped out Jaguar XJS on Top Gear. They raced an old XJS against 911 Turbo, Diablo, TVR? - No NOS system - 18 secounds down after 1 mile - with NOS it won the same race - blew everything else away!
/ubbthreads/images/graemlins/cool.gif
It worked for a clapped out Jaguar XJS on Top Gear. They raced an old XJS against 911 Turbo, Diablo, TVR? - No NOS system - 18 secounds down after 1 mile - with NOS it won the same race - blew everything else away!
/ubbthreads/images/graemlins/cool.gif
Ford has the engine you guys are looking for, albeit in the experimental stage. It is a new V-10 427(also to be available in 351 & 390 disp), putting out 590HP @ 6500RPM,
will turn 7500RPM, and develops 509 ft/lbs of torque. It it only a hair longer than the 4.6L, and the 351 version is planned for a new Boss 351 Mustang. The 427 may be slated for the Ford GT in the future, according to Automotive Design & Production Magazine. Still, a beefy gearbox would be a must! I doubt that it will be cheap either! /ubbthreads/images/graemlins/shocked.gif
will turn 7500RPM, and develops 509 ft/lbs of torque. It it only a hair longer than the 4.6L, and the 351 version is planned for a new Boss 351 Mustang. The 427 may be slated for the Ford GT in the future, according to Automotive Design & Production Magazine. Still, a beefy gearbox would be a must! I doubt that it will be cheap either! /ubbthreads/images/graemlins/shocked.gif
Ron Earp
Admin
I just picked up Muscle Mustangs and Fast Fords (yes, good dyno articles every now and then). The 03 Cobra (4.6 DOHC, Eaton blower), with only some simple mods - pulley change, throttle body change, cats, and full exhaust with headers, was making 530hp and 600 lb/ft at the rear wheels. Good huh?
Not the focus of the article. The article was to highlight a Kenne Bell blower swap on the car for a screw type setup. Once done the car netted 708hp and 670 lb/ft. That is quite impressive for such a small mill and pushes the porky (3800 lbs) Mustang at 11.00 at 139.60 mph. These are all rear wheel numbers, not crank numbers. And, the supercharged motor has all the drivability that you'd ever want - low-end torque and horsepower - it isn't peaky at all, table like torque production.
I think I need to go drive one of these cars and see what kind of deal I can get on one for a leftover 2003 or used 2003. Man, not bad.
Still, the motor is too big and I'm not a huge fan.
Ron
Not the focus of the article. The article was to highlight a Kenne Bell blower swap on the car for a screw type setup. Once done the car netted 708hp and 670 lb/ft. That is quite impressive for such a small mill and pushes the porky (3800 lbs) Mustang at 11.00 at 139.60 mph. These are all rear wheel numbers, not crank numbers. And, the supercharged motor has all the drivability that you'd ever want - low-end torque and horsepower - it isn't peaky at all, table like torque production.
I think I need to go drive one of these cars and see what kind of deal I can get on one for a leftover 2003 or used 2003. Man, not bad.
Still, the motor is too big and I'm not a huge fan.
Ron
I must agree, that is one beautiful piece of engine hardware. May have a bit of clearence problem with engine pulleys thou rubbin on the firewall. The injection trumpets, I think would look awesome reaching skyward thru the rear hatch in thier polished state. Out of curiosity, if not a rude question, What sort of dollars do you have invested in that engine?
Scott
Scott
I mentioned this before, but Tilton sells a clutch system that can be used to drive a belt driven oil pump, etc. Thus one could use this to drive a blower.
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