serious supercharging question. compression ect...

[ItsStockOfficer]

N/A you will need to spin to at least 9000 rpm to make over 230 whp.

 

[na90dsm]

think ill be ok spinnin a stroker to 9k.

 

[ItsStockOfficer]

Yes.

 

[na90dsm]

thank you for your help

 

[pneumo]

You might want to play around with the injector size page at RCeng.com Turbo engines have different fueling requirements than NA, but I'd guess you would need something bigger than 450's to get 400 HP.

 

[na90dsm]

ae the injectors different impedence. i think hey all have the same deal.

i was just reading a few posts ad people are talking about 550cc injectors on a n/t. will a stock head fo enough air to support those injectors on a n/a.


sorry if my typing is wacky. ive been checking it an my keyboard is dying slow

 

[sidoze]

"everyone has crazy ideas. everyone. i dont liek hondas at all. i hate them. there ugly, sound retarted, and i will not be a honda guy ever."

And I'm sure your 420a or 4g64 will sound worlds better than a honda with a swapped motor with similar stuff done

Only way to get rid of the angry bumble bee tone is mad displacement, a boxer engine or heaven forbid a turbo.

I understand why you want to be different but theres probably better and more reliable ways to pull off what you want out of your car in my opinion. You first asked about torque and not wanting to rev high but now your considering 9,000 rpms, you obviously havent started and are still thinking so I want you to think about another option that might better suit you....

http://dsmtuners.com/gallery/showgallery.php?cat=500&ppuser=10108&perpage=12&sort=1

Check out the link above, thats a local guy that wanted to be different from the croud and didnt want to spend more than he had to and wanted a fast car. He bought a near totaled first gen and swapped its motor, harness and ecu into his car. At that point only being out 1500$ at most he went down to turbo performance in VanNuys and got there turbo kit and frontmount.

For easily under 5,000$ and doing the right things to be different he now kicks the living crap out of my car and he is only running 12psi right now.

Hope that helps you in your decision, yea putting a 1g in an NT isnt for everyone but neither is sick all motor action and nitrous either.

 

[Blizz92tsi]

na90dsm,
If I were you I'd stick to your guns. If you want a built, stroked, 11.0:1, N/A motor in your dsm I say go for it. Don't listen to all these negative posts. Our import scene and the 4g63 wouldn't be as far along as it is if everyone always went with the popular oppinion. If everyone did we would all have a V8 (at least a 350), and have mullet hair cuts.

If you do plan on going N/A and 11.0:1 you can forget about the NOS on pump gas.

If you do tire of doing the N/A motor all you'll need to go turbo is the requisite parts and a different set of pistons.

For parts for your to stuff in your N/A head I personally don't think you can go wrong with Crower. A set of their springs and Ti retainers, with at least a 3 angle valve job, and a set of cams and you'll be good. I'd hit the non-turbo forums hard and look for some good info there.

Good luck with the N/A dreams and keep me posted on how its going.
Later.

 

[ItsStockOfficer]

Then he would need something in thge 12.5 to 13:1 compression area for real decent power, and it would be a race gas only car of course, but he might get 250 whp that way.....at 9k...just seems difficult, but worth a shot...

 

[na90dsm]

yea im gonna try the n/a motor idea. i had asked the guy if i could use these pistons on pump gas and he said it would be ok. i forgot to ask about the nitrous.

so you think i will not be able to pull off using nitrous with that comperssion?

 

[Blizz92tsi]

I'm not speaking from experience, but 11.0:1 will probably be pushing it on 93 octane, and then adding nitrous on top I believe could only spell disaster. Think of nitrous as another form of forced induction, and if you plan on using 11.0:1 its probably not an option. It might be possible if you use the nitrous only in racing conditions when using a very high octane race fuel.

Disclaimer:
I am not in any way familiar with the use of NOS, but merely stating my understandings. Also I am in no way stating this as fact. Please confirm/correct any of this information with someone more knowledgable about NOS than I.

 

[crackheadmel]

Why lower the static CR just to go boosted? I understand that it would give you a larger margin of error in tuning aka. dont worry as much about blowing stuff up

However

11:1 CR + 10psi would give you what, 18:1 effective CR
9:1 CR + 10psi would give you about 15 effective CR
8.8:1 CR + 10psi would give you about 14:1 effective CR
8.8:1 CR + 20psi would give you about 20:1 effective CR

Now obviously yes, look the 8.8:1 with alot of boost makes alot of power, more than any of the others. But, your low end response is going to be less than favorable, its nothing that i would want.

Now, 11:1, great low end compared to the 8, and with 13psi of boost should theoreticly make just about 20:1 effective CR. Now look, we have the same effective cr, we have a higher static cr so off boost repsonse is going to be much better, and should have the top end, anyone who has read even a basic turbocharger theroy book knows, when you compress air, it gets hot. the more you compress it, the HOTTER its going to get, which is going to have a higher compressor outlet tempeture? obviously the Low cr high boosted hairdryer lookalike choice

bah i have to go, maby ill finish this post later

 

[na90dsm]

please finish the post. id liek to see if i could run nitrous with this compression ratio.

 

[Blizz92tsi]

I'd like to know what kind of compression ratio crackheadmel is running in his car. Or would run if he could build his own motor. Now I understand that 11.0:1 is going to have great off boost response. Adding 10psi to that is going to give you awesome power. That's obvious. What I want to know is how you're going to run an 11.0:1 + 10-13psi while on pump gas. It's not going to be that easy. na90dsm is going to need to a) be a super tuner or b) have a super big budget for rebuilding the engines he's going to be toasting at those levels. From what I understand he's wanting to build a fast N/A dsm. And if he's like most DSMers it's his daily, he's on a budget, and will probably need to run on pump gas.

How many other DSMs are there running 11.0:1 with 10-13psi? Then how many are doing it that aren't dedicated race cars? Then how many of those racecars are being privately funded?

I just don't see the possiblity of na90dsm being able to do this.

 

[Blizz92tsi]

na90dsm,
There's some questions we need answered before the discussion can progress. Please answer the questions in great detail.

Is the car going to be a daily driver, weekend warrior, or dedicated racecar? Will the car run on pump gas? Pump and race on the weekends? Nothing but race gas? Alternative fuel (Alcohol, methanol, etc.) ?

What mods have you done to the car so far? What mods do you have sitting around waiting to go on the car?

I'm pretty sure you answered this but what direction are you going motor-wise? N/A? Supercharged? Turbocharged? Nitrous?

What does the budget look like for putting together this fast DSM?

What kind of knowledge/experience do you have with cars? Will you be working on the car yourself? All of the work? Some of the work? Or will have someone else doing the work?

What kind of racing are you planning on doing with this car? Street? Drag? Autocross/SCCA? Roadracing? Lap of America?

Why are you stuck on using nitrous?
If this is another I wanna be fast and furious thread I'd personally like to see it LOCKED!!! I've been trying to be helpful, but the more I hear the more it sounds like a noob or wanna be.

 

[pneumo]

There is a reason all the fast DSM's are built nearly the same way; because that's what works. If you want to go the 11:1 route don't be suprised if your engine ends up to be slower than it would have been if you did something more ordinary like a 2.4L/9.0:1 compression/ high boost on a big turbo engine.

 

[sidoze]

We'll hes selling his reliable car to get something that will not be a very good daily driver from all the things being thrown out.

He seems up on the hype of everything like blitz is talking about, and if thats the case I'd say keep your jeep and save money. Selling your backup transportation to sink all your money in something that will very well explode if your not extra careful is usually called being "wreckless".

Sure reving a motor to 9,000 and running 11:1 is a really cool feeling but it isnt practical for what hes probably trying to do. How many all motor cars do you know that are reliable for 100,000 miles? Ive seen a couple 1st gens with 20gs that are nearing 200,000 on the stock bottom end and that same 1g would probably spank any all motor car you throw at it.

I'm talking about the street mind you, I know of all motor civics on slicks that run 10s too

 

[na90dsm]

im not lookign for reliability. im looking for something that i built. something different. my jeep isnt going yet. i ride my bike to work everyday.

it needs a rear driveshaft and ive been building it up for abotu 6 months. it was being built to sell. i worked the hell outta that thing.

my next dsm will be this n/a stroker. i dont want turbo. if any motor is buitl right it will last regardless of mods. unless its somehting that is very severe.

we have these things around here that are called garvy boats. homemade hulls and have car motors in em with a dirrect drive setup. this guy is running a 426 with 12:0:1 compression and has 4 years of all out races on it. high revs everytime and has zero probs.

just matters who build it and if they know what there doing.

 

[Blizz92tsi]

Answer the questions please. The questions in my last post.

 

[ItsStockOfficer]

Originally posted by na90dsm
im not lookign for reliability. im looking for something that i built. something different. my jeep isnt going yet. i ride my bike to work everyday.

it needs a rear driveshaft and ive been building it up for abotu 6 months. it was being built to sell. i worked the hell outta that thing.

my next dsm will be this n/a stroker. i dont want turbo. if any motor is buitl right it will last regardless of mods. unless its somehting that is very severe.

we have these things around here that are called garvy boats. homemade hulls and have car motors in em with a dirrect drive setup. this guy is running a 426 with 12:0:1 compression and has 4 years of all out races on it. high revs everytime and has zero probs.

just matters who build it and if they know what there doing.

Thats simply not true. There is something called a rod to stroke ratio. You can look at this in depth if you want, the the basics are that if you have a real long stroke with a real short rod youdrive the rod side ways into the cylinder walls. I don't think you will have a serious problem with it for 40 or 50 thousand miles....but it does exist, and any engine builder knows it.

 

[ShapeGSX]

Centrifugal superchargers don't really give you all that much low end torque. They still have to spool up. It is just that their "spooling up" is tied to crank RPM. Off idle, a supercharger might give you a little more torque. But not a ton. And nobody races off-idle. A turbo will actually give you more torque, lower in the RPM band.