cekim

Well, I never say anything is "impossible" - except maybe getting me to appreciate a honda civic regardless of the amount of HP - but, just consider just one aspect...

If you build an N/A beast you will reach your limits of what you can do with compression because of detonation (without going to race gas)...

So, you have your 10:1 + N/A engine loping along and you are as happy as a clam (except when you find yourself idling next to a cop-car at a light)

If you reach that limit and then add 8-15 PSI depending on how nuts you want to go - you now need octane ratings you either can't get or don't want to pay for when driving on the street...

So, what I said before pretty much captures it - they are somewhat divergent paths and become more so as you approach the extremes...

In the middle of the range - what is good for one is good for another - more flow, more gass, less weight, more strength...

But by the time you get to 500HP N/A you have made some choices that are not good for FI...

cekim

FWIW - my take on the likely path of the future (assuming we don't have a catastrohpic fuel crisis)...

The inflation adjusted costs of FI have come WAAAY down...

If you look at KB - getting 1000HP isn't the problem - just change the pullies and add fuel...

Keeping the parts of the engine on the inside is the challenge there...

Getting 1000HP from a N/A engine of this size - well, that isn't going to happen any time soon...

I suspect you are going to see more and more "working man's sports cars" coming with FI...

Look at Saleen - the "SC" version isn't even the most "Extreme" - for that you need to buy the, uh, er, "Extreme" (ok Steve, time for some more creative naming!)...

Then there is the whipple effort by ford...

It is, on a relative basis, just too easy to get HP from FI now that the black magic is gone (which is mostly a function of the quality/tolerances of manufacturing). I expect them to take the easy path.

bl1nk

So its not possible to back down the compression once you decide to go FI or is it not that simple and Im missing some things?

classj

I wouldent play with the heads and cams until I know whether I am putting a blower on it or not. Building a engine optimised for a blower is one thing. Building a strong NA motor is another.

As far as drivibility, when you get into large cams, big heads, intakes, etc. The low end of the motor tends to suffer.

Best way to make power NA is with cubic inches, compression, and good heads with reasonable valve lift.

But I have to say, these twin screw blower kits are damn tempting if they work well, install easily, and are relibble and livible.

cekim

Compression is decided by the geometry of the poston/rod/crank and the size of the cavity in the head...

So to change it you would have to do one or more of the following:
a. change the shape of the pistons
b. change the heads
c. change the crank

So, certainly not an easy thing to change.

mikefan20

+1 right there with you on the plans. Don't know if I will ever trust the kid until he is well into his 20's

bl1nk

So then its just not smart to try to max out N/A by changing heads pistons and the crank shaft and then try to go FI because youll have to back it off some correct?

So I guess what I really should be asking is.. How aggressive can I go while N/A but still keep the ability to go FI in the future.. ?

bl1nk

Right.. I understand.. but I dont measure maturity by age.. it comes down to how they act and treat the things they are given/earn. I am only 18 and my dad is helping me buy this car so I cant deny my son/daughter that right unless they arent able to handle the responsibilty. So for me to tell my kid that they arent able to have a powerful car at my age would be hypocritical.

cekim

It is really less a matter of degrees as it is cross purposes...

A N/A engine has to take every advantage of the inertia of air-flow to get its power...

Wild cams are "wild" because they are timed to keep the air moving in and out as fast as possible at higher RPMS at the expense of bad behavior at low RPMS where the air has little/less inertia...

A SC engine is comparatively the opposite - the intake path is under relatively high pressure - all you need to do to fill the cylnder is open the valve for bit and viola!

I guess what I am trying to say is what classj said - I would decide from the start and stick to the plan... trying to follow 2 paths means you are going to build something that is ideal for neither path...

There are mods you can do for both that are "neutral"
1. weight/inertia - aluminum/carbon driveline parts
2. strength (crank/rods)
3. strong clutch
4. port/polish heads (good for everyone)
5. main studs and other reinforcement at the bottom

Where you have to make a choice is compression and cams - there just isn't much you can do to help that out...

Wild N/A means heading towards/past 10:1 compression and wild FI means going down towards 8:1 from where you are now stock...

I admire your long term planning, but I think it might help you have a little more fun in the mean time to recognize that by the time you have the time/desire/resources to add FI to an already 400-500HP N/A engine, you will hopefully be less concerned about the cost of a new or reworked shortblock at that point (or frankly, you should not be doing it!)...

It might also help to realize that high HP N/A is NOT the cheap route... $6-7K for a blower on a stock engine is a real good deal compared to what you need to do to get the same HP N/A...

bl1nk

Thanks alot, definately alot of information. I guess this is when I need to take some time to figure out whether I want to go FI or not, because it sounds like that is what is holding things back. But while Im deciding, its good that I have things I can do that wont effect the engine negatively either way I go..

About the crankshaft, how do I go about exhanging that out for a stronger one.. should I buy another that is the same, timing wise but forged? Also about the clutch, I have an auto so.. what do I do about that?