How much horsepower is enough?

This ought to be a spirited topic and is something I have wrestled with. I may as well go first.

Obviously the Vw pan chassis wasn't engineered for triple digest HP and the accompanying torque of today's performance engine packages. John C. of aircooled.net told me with anything over 140 HP he would suggest adding a Kafer Cup brace. I am confident modifications and/or add-ons can be incorporated to handle the power.

I have read Jake say that over 140 HP when driving on "wet" streets you have to be darn careful.

Someone posted that for each eight pounds your car loses you gain a HP, or something like that, which reversing the equation I suppose that means a 1700 lb. car with 140 HP would have the same performance as a 3000 lb. car with 300+ HP (someone check my math).

By my thinking 140 HP is the gateway to serious power. For my two cents with current car I am thinking a bit south of that figure, mainly do to the economics, but I can appreciate someone else may embrace higher figures.

Erik,
Assuming that all other things are the same(gearing, wheel size, etc.), car 2 would have better performance. There is an easy equation to determine this. Simply divide the weight by the horsepower and compare the numbers. Car 1 is about 12:1 while car 2 is 10:1.(lower is better) This is a simplified example which doesn't take into account torque figures, but it gives a good comparison.

-mike
still running a stock 1600 and loving it!

Eric,
Thanks for bringing this topic up. I wonder if the thread will go as long as the T1 vs. T4 did. We'll see. I bought my car used, and it has a 1776cc engine which I assume is a Mex crate motor. I'm not certain if the engine arrives in the states at this displacement or it has larger jugs installed after arrival and don't know who does the work for Kirk if it has to be bumped up from 1600cc. I also don't know how much horsepower it has. Anyone know for certain? My guess is around 75bhp with the single carb setup. If and when I have a new engine built, I was thinking in terms of about 125 - 130bhp. I think that's enough to make the car exciting for me. It's OK now, but a little more grunt for the hills of Tennessee would be welcome.
John H.
2000 VS w/ 1776cc

If you had unlimited money....
When my 1776 goes my thinking is that I will replace it with an engine of 2000 to 2100 that puts out 120 or so HP. Mine is non-flared and anything more would require larger rear tires than I can get under the body IMO. I think my 1776 can break the rear loose on wet pavement pretty easily now.
ed

"How much HP is enough?" Depends on the depth of one's wallet, nerves as well as the amount of your life insurance policy!

Six months ago, I installed a 160HP Jake Raby Type IV engine in a Speedster, the trans that Jake selected is beefed up to handle the additional HP, the gearing is matched to the engine and tire size Without doing your homework, you will surely be disappointed with the performance..
My experience with this engine is that Raby has found a perfect combination of HP ratio for the Speedster application...
This particualr Speedster runs up very fast and smoothly, with a torgue that is amazing! I always feel completely in control at all times.....

The answer the pending question 160HP is the right street combo that will keep you in a permanent grin mode!

BTW this particular Speedster will be offered for sale in the coming weeks ..... has leather interior and removable hard top.

Alan Merklin

This is to Alan M.

Good to see you around here once in awhile. How about an update? What have you been working on lately. I know you always have a project or two in the works.

Greg Billesbach

Alan, glad to hear you chime in here, especially about the engine....please drop me an email, I have a buyer for that speedster that is 99.9% ready with cash in hand!

I would say that 120BHP is a must, 140 is comfortable and 160 is able to make it feel really nice under the foot......180 and you are getting into areas that you may break other aspects of the car...

150-160 is really sweet!

With a 2176 I can easily chirp third on drive pavement... and as for wet roads, I can say you have to be VERY careful. I wasn't used to the added power at first going from a 1776 single carb to a 2176 and took a corner and barely touched the gas. The rear end just slid and reflexes (or just dumb luck... or a combination of both) kept me from doing a 180. Reinforcement is key as you add power. A beefed up transmission (welded third and fourth gears... mine is a 4.12 by Der Transaxle) is a must are heavy duty axles and a traction bar... and not the Gene Berg kind that bolts to the frame with rubber cushions/mountings. Tracey Grimm makes an excellent bar that spans the shock towers and will definitely prevent wheel hop. With a 2176, I think I have "enough" horsepower (famous last words?). My car is very driveable yet powerful and "torquey" enough to obliterate most cars at stop lights.

I figured this discussion would be a duck and cover variety. Pleasant surprise.

Colton, was your engine dyno'ed by the builder? Curious about your HP level. Didn't know if your builder uses one. Some builders, depending on the input of their customers, offer the same engine size in different states of tune. Was your engine considered a "hot" one? I will look-up the photos you posted earlier; do you have some close ups of the install? Still curious about the fresh air vents to the carbs and where the feeds originated.

For my two cents the great thing about a dyno is the engine can be broken-in in a controlled environment with various gauges to monitor everything, the carbs set to perfection and of course the print-out would be nice to have. If your engine was dyno'ed did you receive the "power graphs" with your engine? Care to share the basic numbers?

Roger that George. Well stated.

Erik, Although it might be nice to have dyno. specs in printed form, our methods for figuring horsepower come from years of experienced engine building. It's our feeling that the actual performance of the entire car is more valuable than a dyno slip produced from just the output of the motor, thus explaining why we take our cars to the race track. Track tuning also aids in proper set up of the suspension to ensure maximium performance. (You can calculate the HP by using the MPH at the end of the 1/4 mile) The fact is, it doesn't matter how much horsepower a motor makes if the rest of the car can't handle it.

Colton's motor was designed to produce approx. 145HP, give or take 5% and should easily run high 13's in the 1/4 making it competitve with a new Camaro or base Corvette ~ pretty nice considering it will be able to maintain fuel consumption of 22.5 MPG or better and perform reliably on the street.

As for breaking our engines in, we have a 2 step process. First we run the motor on a stand prior to installation in the car so that everything is easily accessed for adjustments or corrections. The second step is to break the motor in after installation to see how it will perform during it's 'intended' use. (i.e. on the street, at the track, etc.) This gives us a chance to address issues such as cooling which might not be recognized on an open stand.

Speaking of cooling, you asked about the cold air ducts we installed. Each duct (there are 2) was installed in the sides of the engine compartment behind the carburetors venting through to the inner rear wheel well. Combining this modification with sealing the engine compartment and raising the rear deck lid allowed enough air flow for the engine to maintain a temperature 20* cooler than before when driving the car on the street. As you probably know, 20* can make a big difference in the longevity of a motor.

Now, to answer your initial question of "How much horsepower is enough?" It's been my experience that the amount of horsepower needed to qualify as "enough" is relative to each particular driver. Like a new pair of shoes, in time you will become comfortable with what you have and eventually the feeling may wear out. What may be more than sufficient for some would bore others to sleep. My personal opinion is that there is no such thing as 'enough horsepower', just make sure you're being responsible when using it.

Hi Ann! Great to see you here and thanks for that great response!

Ann,

Indeed a well thought-out response. Hope you and your husband will visit the site in the future and offer your insigt.

BHP in a Speedster replica is a balancing act - car weight, transmission ratios, suspension components, weight distribution, tires, and driver experience are all part of what makes power useable on the street, track, or 1/4 mile.

As you go up on power you should strengthen transaxle components and choose different ratios. A stage 1 Kennedy clutch and aftermarket pressure plate (or stage 2) will probably be necessary. Four wheel disk brakes will be very advisable. A "tuned" suspension will work best. Premium tires like Michelin, Conti Sport (Continental) with good rubber compounds that are speed rated should be used.

This is one of the reasons I suggest that wanna-be new buyers do a lot of research before they take the plunge.

(Message Edited 12/2/2002 4:57:00 PM)

Hi Ann; now I know why I couldn't get you on the phone this afternoon - you've been surfing the web... :o)

(Message Edited 12/2/2002 4:57:42 PM)

I did just fine for years without a dyno, but it sure is nice to see what things actually do..

Having a dyno is actually a pain in the rump if you take the time to ensure the engine is really dialed in. Mine is really nice as I don't do any install work any longer and never get to drive the car. It is also nice to work an engine out for a few hours and drop a load to it for 30-45 minutes to see what your adjustments actually do for heat and etc. Most of the time, engines don't leave my shop with adjustments that they had during testing that made the most power.

The trick is finding the settings that release the engines power at a street level,and still yield the best power with least amount of heat being produced.The dyno is excellent for that as it gives an ambient air temp equal to someone that lives in Arizona in the middle of August. My favorite part is doing all the break in and telling the customer to bolt it in and run it wide open, no break in required at all, first oil change is done,carbs syncced, Hot and cold leakdown checked, hot and cold compression checked and valves adjusted.

The way I build engines and ship them (alot go overseas) a dyno is a must for my shop, but for guys that do the install they can get by without it. About one out of 6-7 engines we build has an issue that the dyno shows us, that one engine can be a nightmare for me if it were to leave and break on the customer.

Guys that use a dyno to brag are doing it the wrong way, its only a tool, a tool that I have come to love, and hate at the same time, its not a necessity, but is nice to have.

'How much horsepower is too much?' is a question I'm wrestling with right now, along with 'how much can I afford?'. I had a 1776 with mild cam, 40 Webers etc and just felt I needed more power. So, my 2110 is just about ready to go back in. And here lies the money part. Building a strong 2110 with about 120-125 horsepower (I think) is affordable (not in my wife's eyes). But to go any higher starts to cost a lot more money. I'll be running the same 90.5 pistons (they only have 3000 miles on them), 044 heads (40/35.5), an 82 mm Scat crank and rods, the same mild Engle 110 cam and the same 40 Webers with 8.5:1 compression. I've also had the transmission rebuilt with a stronger first gear and a longer fourth gear and I'm installing rear disk brakes in the spring. I haven't decided what exhaust system I will put on. My builder is going to install a 1 5/8 merged system so I can try it out. I did indulge myself and order an Achiever Power Pulley, from Gene Berg. I wanted a power pulley to gain back the extra power loss from my 911 style fan shroud (when compared to the dog house style) and I'm not worried about overheating (Canada, remember). I stayed with a mild cam so I can get through Air Care. Will it be fast enough....stay tuned.

My 911 fan assemblies use a 1.3:1 drive ratio, the same as many 911s used, even less than some.

You may find that the power pulley is a tad bit too much overdrive for the 911 fan you have, whats the diameter of your top pulley? there were 3 different top pulley diameters for the genuine 911 fan assemblies..

I have found that with most all 901 and 930 part numbered hosuings with 75-90 amp alternators and the smallest pulley up top that the dry sump pulleys from Sact work the best, they are a tad bigger than 5", gives a good ratio.

I actually have had the best luck with the earliest 11 blade fan and matching pulley half, mated to a 75-90 amp alternator and a dry sump pulley, this yields a 1:1 drive ratio or darn near close to it. this gives the most power and helps to prevent OVERCOOLING, the next enemy in the 911 fan saga. Being in Canada, thats a realistic thing for you.

Hey Jake, just out of curiosity...how do you know whether or not your customer will have issues with cooling, space, (fit in engine compartment) electrical, add on compatability such as A/C, etc. if you don't do the install for them? Also, what do you do to resolve such issues if you're not there to over see the installation process as these problems may arise? Doing custom work like this you must know that 95% of the time problems occur after installation, not before during the break in period on a stand.
Also, I can't understand your fear of being sued as reason for not doing road tests & installation - insurance covers that & all things considered it's relatively cheap.
Please don't take my questions the wrong way - I'm not trying to be sarcastic. It's just that after years of dealing with people coming to us to build a motor I've noticed that most of my customers couldn't identify a 13mm wrench in a pile of standards, therefore I wouldn't take the chance on having them do damage to one of 'my' motors not to mention my reputation.

It is very risky, but I have to spend alot of time trying to walk folks through the installation, and have had more than one or two engines suffer due to restrictive engine bays and mostly bad firewall insulation being sucked into the fan...it happens.

Thats one reason I do everything and only build turnkey engines with exhaust,carbs and all in place..there is still a risk that it could be goofed up, as anything can be. The VWs biggest enemy is the wrong mechanic with a 13mm wrench thats for sure, it kills more than junk parts and bad internal labor anyday of the week.

We have very good luck, very,very good luck. In the last 2 years I have installed 3 engines, all the rest have been done by the customer. It seems the guys that take the engine to a local shop for the install have the worst luck, as the shop cares nothing about my engine, or the customers engine and just slap it in.

The main thing is actually letting some jobs go because of being too risky, some people ask way too much of these engines, and the cars they are installed into. One of the biggest things I have had to do is learn how to say NO when the customer has cash in hand, its just not worth it sometimes, I'm sure Kurt knows what I'm talking about.

As for restrictive engine compartments:

I have found that many speedsters need the "Rain tray" cut out and that normally allows enough air into the fan and carbs. Especially for 911 cooled engines.

As for being sued and all that Jazz, my insurance already runs 3,000 bucks a year just on my shop, after July1 of this year that would have increased by 30% if I worked on vehicles and test drove them. I'm classified as an engine manufacturer, and a "Shop keeper's policy" was not cutting it any further. In todays society peple are just waiting to nail you, or nail anyone. To protect myself and my property I had to make decisions and I did so. It did not hurt my feelings though as it cleared up alot of space behind my shop and now the only cars here are mine.

Kurt, Glad to see that you still do install work, I have to turn down alot of work because I don't do installs, and I'll be happy to send those guys your way.

Being a former member in good standing (no sense, deep pockets)of the Porsche Retirement Club, I agree with what is developing on this thread.

I used to spend a lot of money to go just a few ticks faster at Time Trials and Solo One events.

I used to spend a lot of money on newly developed technology, some under the hood, some under the car itself, and of course the dough to keep it cool...

In the end some of the money spent was folly, some of the money spent was life-saving (me and the engine) and some didn't equate to horespower at all but rather to support the horses I had.

I've now broken my vows and entered a new chapter of crazed, headlong retirement spending, 'cuz I can't shake the need for speed.

I'm of the opinion that 165HP is a minimum, for me.

I'm pleased with what German Car Clinic has orchestrated under my hood to date. It is reliable, it is quick, sort of, I have a lot of juice on hills and a strong RPM range, but I'm still looking for more...

This afternoon I had an opportunity to scoot up to 100MPH and the time it took to get from 90 to the magic mark and a little beyond was vexing. Add to that speedometer error and I was probably just kidding myself anyway.

It's gotta have guts, and in my mind 165HP is the stepping off point!

MM


PS: The Porsche Retirement Club is where you own the Porsche and all your money goes into the care maintenance and feeding of said Porsche, with the benificiary of all this spending being your mechanic, who has retired early yo an island he bought with your money. If he's a cool mechanic, he has named a beach after you and encourages you to visit some day when your credit cards will allow!

Basically all of the posts in this thread addressed mechanical issues. IMHO there is another area involved; the driver.

Someone who has driven high-powered performance vehicles for a long time and is in good physical shape can handle more horsepower. Someone with no high-powered performance vehicles background is not going to be happy with a level of horsepower that would satisfy the previous driver. Someone who is in terrible physical shape should not IMO even attempt to drive a high-powered performance vehicle with the possible exception of a slow buildup to high speed on an arrow straight highway.

Aside from the physical requirements of speed, there are also the menatal requirements of speed. Richard Petty, the famous stock car driver, noted that he was somewhat afraid of heights but had no fear at all of speed. If a driver is not comfortable with speed, no amount of experience and/or physical condition is going to make up for the mental handicap.

There is also attention. A short wheelbase car such as a Speedster has to be driven ALL the time. If the driver is not willing to concentrate at high level, 60HP may be too much.

Finally, the drivers of a car determine how much HP is too much. If one of the drivers can handle 200HP and the other only 50HP, then 75HP is too much. This last can be a real problem as the question "Honey, how would you handle power oversteer?" is not the beginning of a romantic evening.

Say's you! Personally I find an evening of spirited driving to be the MOST ROMANTIC thing a hubby could propose :) Anyway, it is correct that the idea of the prospective driver/s must be addressed when determining how much horsepower should be added. It's a well nkown fact that the most dangerous thing you can face (whether on the street or at the track) is a driver who is not comfortable/confident or doesn't have the ability to maintain control.

BTW, thanks Jake for answering my ?'s!

Ann Metzger:
I have found numerous wives who find an evening of spirited driving to be an extremely romantic prelude, however, not with their husband. Alas, most of the husbands did not find my interaction with their wives romantic at all. It would appear that romance differs from different points of view.

Thank Bhudda for kung-fu!

I'm not sure what you're trying to imply Alan, but my husband has enough driving skills & horsepower to keep me in the car with him.

Ann, I think Mr. Bima was implying that he leches after other mens wives, which can be a very dangerous and sometimes fatal hobby. Gun-fu can beat kung-fu every time (I am Shotokan but also shoot in matches).

Hey Jake I concidered cutting out the rain tray and most likely will do it yeat. Did you see the air rams I hid under the rear fenders? I may inlarge thoses hole more as well. If I cut out the rain tray I will remove the intire bottom and reglass the inside and make new hinge mounts to make it stronger I may put a rack on the outside.It would be better if there was a inner metal support that catches the hinges, latch, and the rack. I will then be looking for the disrtibutor and alt., water proffing kit to protect their eletronics. I will take any sugestions.

(Message Edited 12/3/2002 6:01:49 PM)

The question I assk myself is how much horsepower can I have and still go to heaven, enough is when I can spin the tires leaving the turn and keep them spinning until I brake for the next turn. We have build cars from 65 to 295 HP and like someone said it all depends on the nut behind the wheel, my Speedster had a 1600, my wifes has a FI 914 2.0. I let each customer understand the realities of HP vs torque and then build to their needs and their $'s. The 285 car was for a 16 year old girl with Bondurant training and a 4.0 GPA, she has always used it wisely.
If the trans gearing is set to meet the output of the engine and the weight of the car and the size of the tire you can go fast with a 1600 and feel you have no power with a 2110. Who hasn't felt his old VW was quick only to realize it was first and second gearing with a high geared final drive that gave that feel.
I like the HP to weight ration personally but some people live on torque.

Okay, great points were posted. I like the total package approach: engine should match brakes, which should match rubber, which should match transmission/suspension/ etc.

What I am trying to figure out for myself is the exact point where you get good HP for the bucks but after that point things get expensive in relationship to the additional HP gained. In racing they used to say the first 500 HP is fairly cheap, the next 10 HP, the racer's edge, is very EXPENSIVE. Or for example let's say you are taking a date to a nice restaurant and want to get a "good" bottle of wine. A good wait person won't steer you towards the most expensive bottle on the wine list even though had she/he done so your end of the evening check would have been higher & thus a bigger tip. Is that 20 dollar bottle that much different that the 40 buck bottle?

For me, focusing on T4 engines, it appears the 2056 fits the bill as there is no clearancing involved and it is a relatively easy build compared to larger displacements, and it will make 120 to perhaps 140 HP. Those HP figures seem to be the gateway to bigger numbers but perhaps more expense. Of course if I won the lotto my thinking would likely be different.

I think that maybe the question of how much HP is enough is relative to the other question you need to ask yourself... enough for WHAT? If you don't know what you WANT or NEED it for, then maybe "enough" is an infinite value? As much as possible? You need to first determine your goals, needs, and expectations and weigh them versus the potential problems, issues, and cost... and not only with the engine, but with everything else related to it. Then, maybe you can quantify what "enough" is for you because it is definitely a personal opinion and decision.

Eric,
You sound like you are on the right track, but are you looking for affirmation that you have made a good choice? It sounds to me like you have carefully considered your power requirements and have made/will make some modifications so that the chassis can handle your new found horsepower which I think is a good approach. My parameters call for somewhat more power and an engine I can depend on if the revs climb up beyond my currently imposed limits and won't become what George referred to previously as "a grenade." My feeling is that if I decide to go for big horsepower, perhaps I would be better off just selling the car and having one built that has all the right stuff from the get-go. Pipe dreams are cheap but boy toys can get expensive.
John H.

Lots of different slants on the same question. I can only add that enough BHP to get you out of trouble in a traffic situation would be a good idea; this would probably be at least 130 BHP at the flywheel. An example of this happened to me a week or so ago.

I was in the right lane of a 4-lane divided highway in heavy commuter traffic (MD Route 4 south, semi-limited access). Something happened up ahead in the left lane and it began to slow; a pickup truck ahead of me in the left lane locked up their brakes and began sliding into my lane directly in front of me. I had down-shifted when I saw the brake lights ahead, so I gassed it a bit sideways then went around him on the shoulder instead of hitting him from behind. Power and throttle response were definitely helpful in that scenario.

Actually I was playing a bit of a devil's advocate in the HP thread. I have my mind pretty much made up with a modest 120-140-ish HP engine for current car, partially due to the economics but also the present car's role was a test platform to test the water, then do it the full-nine-yards with the next one.

Seems to me once you pass the 160+ HP barrier things can happen real quick-like. In my stupid daze I have ridden enough seriously fast motorcycles at triple-digit speeds to have a respect for consequence$. I am lucky to have survived with just remants of serious strawberry burns here and there. Ouch. Don't get me wrong, just like the next guy I am all in favor of kicking out the jams when it comes to HP, but I gotta ask myself, with these cars isn't that a bit like 2 people living in a 8,000 sf house? Probably not practicable but if you got it do it.

That's for sure. Erik, I think you will find 140 horses to be plenty... especially with such a light car. As I have said, I find 145-150 to be plenty quick and more then enough to smoke most unsuspecting cars out on the road. Although, I have to admit that I already find the idea of a 200+ hp turbo charged (maybe 8-9 psi of boost?) Speedster to be kind of an intriguing idea. But, where to put it? What about the cooling? Etc? Maybe in a year or two... :-)

Colton: on cooling get with paul, he's got the answer.

Funny thing is...the longer you own your car the slower it gets. I figure 125 hp will do me for about 3 years...then head work and bigger carbs (plus, by then my wife will have forgotten how much I put into the engine for the 125 hp).

Turbo? That's one department where T1's definitely are a easier/better platform than T4. Me, I am daydreaming about EFI or CIS, but again, for a T4 upright engine you are on your own while T1's already have fuel injection products on the market. Turbo with EFI, now you're talking!

I just want a reliable engine. I'll keep my BMW for going fast. Speedster ownership rests on the fact that the car looks soooo cool. Besides, I don't want to be so fast that no one has a chance to see me driving one of the coolest cars on the road.
-=theron

Theron,
Well said. I didn't have my car built to be the fastest thing on the road- I built it to be as close a representation of the state of the art in 1957 as I could. These cars are the definition of cool, and always will be, even as technology makes them anacronisims. If you want to be the fastest thing on the road- buy an open class sports bike. If you want to drive the coolest thing of all time- stay right here.