MatthewMenze

Hello all,

I was wondering if you guys could answer a few questions for me? I have searched around a while off and on about this, and I have a fairly good idea of what the answer is, but I would like to get a answer to my questions specifically. That way I know I have pieced the information together correctly.

I own a 1995 Honda Del Sol(Slow) Si, with a D16Z6 engine in very mint shape for 130k miles. Part of why I care to mod it at all is because the car is so clean I have considered eating off of it some times. I am looking to mod it mildly. No, I do not expect to turn it into a violently fast car that eats babies and tarmac for breakfast. I just like tinkering, bolting crap onto my car/motorcycle/house/dog/girlfriend is what I call a good weekend. Though I may some day turbo it, it is not currently a plan...It is a Del Slow after all. Currently the only engine mod is a AEM short ram intake (lots of puddles where I live), and some super awesome blue NGK plug wires (we all know bright colors make things FAST, right?) if you count those, haha. For my next 'stage' of modding for my car I intend to get a performance intake manifold, cam, and headers for sure. Then likely some sort of tune or fuel management to account for it, I just haven't decided what route I want to go with that yet.

Okay, with that done, here are my questions:

1. At what point does a larger throttle body become useful beyond just enhancing the 'feel' of the throttle? (Though that alone would be reason enough for me to upgrade, feeling faster keeps me from actually going faster, saving me tickets...In principle.) I have read that it takes a rather intense N/A build for the stock throttle body to actually become a bottleneck.

2. With the above in mind, is there a general rule of thumb for how much horsepower the stock throttle body can support? If so, what is it? It seems most components involved with air flow are rated by the maximum horsepower they can support, I thought maybe there was something similar with throttle body throat size.

3. Engine tuning, when does it become needed I understand that nearly any mod requires tuning to get the full potential out of the modification, but at what point does it become required to see any benefit? How much can the stock EFI system adjust to compensate for mods? I completely understand it will be required if I want to go very far, I just don't have a very good idea of what I can get away with.

4. Again, with the understanding that tuning is absolutely essential to a final build, can the stock EFI system handle any boost at all? For example, could I run a relatively small amount of boost ~5lbs for example, and still have a running car?

5. What would I likely notice more, a adjustable cam gear, or larger throttle body...I understand that neither of these add horsepower, but they do seem to significantly effect the 'feel' of the car. Which, honestly is more important to me; I know it will never be a super-car...But I believe it could be a fun car.

My questions about fuel management are not because I want to get out of it doing it, I just haven't decided what route I want to go with it. I am just trying to understand the situation at a level beyond "I read this this and this, and I it says I need to do that, that and that". Also, again I understand that it may well be easier to just swap a different motor and such in, or go right to a turbo kit if all I cared about was making it fast, but again, I am doing as much for the fun of trying things and seeing how they work (good or bad) than actually ending up with a faster car. Faster is still a goal, but secondary. If I only wanted fast, I would just buy a faster motorcycle...Which I am working on. (Sorry, motorcycles ruined the speed of cars for me...). At the end of the day, I like tinkering and modding stuff...

Thank you very much for your time folks, I know there have likely been similar questions asked, and I have read many of them, but I would really appreciate getting info directly to compare to my own research.

-Matt

EDIT: Very sorry, I forgot there is a performance specific forum, I realize this post should likely be there, is there a way I can delete this thread and re-post it there? Hate to bother someone about it if I can fix it myself. Not sure what my user permissions are for my own posts, as I couldn't find a delete post option.

HondaPartsHero

tldr

Read the links in his signature

https://honda-tech.com/forums/members/grumblemarc-999588203/

MatthewMenze

Thanks for the pointer, I have actually read some of those links and found them very helpful, though I should spend some more time digging through them. I am asking questions to verify that I am comprehending what I have read in my research correctly. Sorry for the misunderstanding.

-Matt

ironiceghatch

I'll go ahead and answer #4. I have personally seen low boost on a stock fuel setup on a civic run a drive just fine. That being said it did not last long with aggressive driving. I'm sure it would be....ok.... To cruise around on as long as you stayed out of the throttle but what's the fun in that. As soon as you come into boost your cramming more air into your cylinders and your stock ecu doesn't know what to do and won't add much more fuel if any at all. Then you will be running lean which will cause catastrophic failure. If this was something your interested in doing you could look at FMUs but they still will not get you where you need to be 100% like an actual fuel setup and tune would.

Just my $0.02