Please explain, then the 15 years or so of "maxi"" injector use in marine aps, @ 18 - 30 PSI. If they stop at 15 PSI....how did they manage to work in boats? Reading ahead, I "get it" that it's a low budget, possibly crude solution, but it works great.


So we agree then; it IS good enough...BETTER than good enough for the OP, his car, most of our cars and certainly, this thread. Coming out and confusing the OP with a diatribe about "pretty bad" injectors, that actually work quite fine in their intended application, isn't helpful at all. You're going to scare the guy away from moving forward with totally viable and economical mods.


Thank you. I thought about the CPI (replaced many) and SCPI too...but didn't need to make a "list" to make my point that the simple, cheap, "low tech" TBI injectors work good enough -and are more reliable than other "higher tech" injectors.


Fair enough. It helps when it's worded that way, rather than how it was in the initial post. You should also be aware that of all the meaningful pit falls of modding CFI (intake runner size, tunability, and stock hardware), the injectors are pretty far down on the list of detriments...to the point of not even being on the list. There are guys making over 400chp/running low 12's in the 1/4 mile (Ben73, for example) on those injectors w/a "CFI" intake. They completely changed the intake (to a different cross ram intake), but kept the injectors.



^These are typical responses I'm used to seeing from the "butthurt", when they've been proven wrong, but don't want to admit it. That's OK...I'm used that immature response by now. I play fine with folk who don't peddle BS. It's quite interesting that you haven't answered a single question that I've direct at you. Hmmmm

 

In the interest of helping the OP make an informed decision abut the direction he takes his fuel solution, I'll share this: I shelled out ~$550 on beefing up my fuel system, which includes setting up parallel plumbing. Sounds expensive, but bear with me.

The total includes 2x 80# big block injectors, a TPI pump, gasket kits for both TBs, blockoffs for the stock regulator & accumulator, the Aeromotive regulator, about 5' out of a 6' line of stainless braided fuel hose (for looks, not pressure ), a pressure gage, and a host of hose ends & adapter bits.

It sounds like the cost may be prohibitive for what the OP is hoping to accomplish...but once the pump & injectors are accounted for (he'll be buying them anyway) and a cheaper GM "marine" VRFPR is employed, the added expense to go parallel drops closer to $300. Less if he stays basic with hose barbs and black rubber.

Of course I don't know how the cost of "Down Under" shipping will affect these numbers, but just figured I'd throw them out there and let him make the call. Maybe shelf the idea for a later mod if it's more than he needs right now. I can provide a part list if desired; I mounted the regulator in the AIR pump's old slot (but didn't snap a good pic of it apparently), so my hardware is slightly different from what CorvetteNorway employed.

Mocked up, except for one lone hose end I neglected to order:



Maybe to some I'm going overboard for too little gain (as may very well be with the tuning endeavor), but I want to make sure my RHS (Ozzie!) heads will be fed precisely what they want

It would be really interesting to dyno compare between a custom tuned ECU, and a stock one, with moderate physical mods...going to try to do that on my build. Pigtails with weatherproof spade quick-disconnects on both computers is my plan, and hopefully at that point I'll have enough practice switching between them that I don't cross-wire my Crossfire and waste precious dyno time!

 

I appreciate this a ton. The shipping prices are a bit of a bite on the backside, but at the same time it still would total less (after conversion rate + shipping) than it would getting someone down here to look at it and work on it. Nobody wants a bar of corvettes down here as far as shops go. So ill be doing a majority of it myself. Which makes all of your info, and everyone else's especially useful to me.

Thanks to you, and thanks to everyone else. Im hoping this still picks up some more opinions, but once again the forums have gone beyond my expectations for info!

 

start porting the manifoil first , 14 - 15 psi fuel pressure , set the timing to 12 deg ( as a start ) ,yes 85 type fuel pump , better cat back , 1,6 roller tip , kn or cool blue high flow air f ilter ........... put all on and try to run the car ........ not happy ? then headers , heads , cam, new ecu , bigger injectors ( and parallel plumbing ) bored tb +++++++ do not do all mods at the same time ...... and yes i have a crossfire

 

Thanks!

Bumping this old thread so I don't have to pollute the site with a second thread asking the same thing.

I'm definitely going to get the K&N filter, as mine is rooted and chokes up my car in warm weather. For whatever nominal gain that gives, I'll be doing it,

Porting the manifold is my next step in my assumed plan, I'm hoping I can buy one so I have a spare just in case (contradicts my low-budget plans, but it's part of how i do things, always have a spare) and port that one. If I stuff it and somehow make an enormous error I'll have the stock one I can throw back on.

Catback is one of the mods I /want/ most but is the least economically feasible at the moment. The one I'm after is 750USD plus 1000+ shipping to AU. It's a mess so it'll be waiting a while.

Now rollers is something I have no experience in and need advice on. I don't understand a lot of the specs, how changing them improves performance etc. I sold my old car because I didn't know what I was doing and I'm sticking with this one so I'm determined to learn. So please explain further on the rollers thing.

I was absolutely ready to buy an 85 fuel pump and just chuck it in because it was easy to mount in place of the old pump. Now everyone's talking about timing and regulators, and that's where my ability ends. If I can unbolt something and bolt the alternative straight in I have no problems. But putting in/changing parts I know nothing about is a tightrope I don't want to walk. Can i get away with not changing the regulator? was any of that large discussion about throttle bodies relevant to my specific build at all?

Thanks.

 

Yes, and no.

You can keep your stock fuel pressure regulator, you just need to remove the plug in the bottom of it that prevents you from getting to the adjusting screw. Remove that....and now you've got an adjustable fuel pressure regulator, for free.

No, the discussion about larger throttle bodies is not relevant to your build. The stock TB's aren't a restriction on any stock or stockish engine. Don't worry about TB's until you've done heads, cam, exhaust, intake...then you might see a gain from larger TB's.

 

and read this https://www.corvetteforum.com/forums...re-intake.html

 

There was so much useful info in there!

The L83 is truly the definition of DIY power then, isnt it?

So what i learned from that is that porting my intake (or alternatively, buying a renegade unit) is just step 1, and more power is in the heads, cam and exhaust.

Now assuming i can port the intake myself (shouldnt be too difficult, just opening the entry/exit ports up a bit and smoothing over the inside of the device) and get my fuel regulated properly, whats the next step?

Anyone know of a cam/head combo that works with the setup? I'd like to not have to deal with the ECU just yet, but its in the works eventually.

I dont know good brands for either heads or cams nor what my criteria would be. I would just like to be able to drive it between mods as its my daily. Thanks so much for everything so far guys!

 

I have and '84 cross fire and before I did all the things you are considering I would most likely just do an LSx swap.

 

That is correct. With the CFI, you have to "earn it"...you can't just bolt parts onto it, typically.


Hopefully, you go further with your porting than you said above. The runners are way too small, and need to be HOGGED from one end to the other, until the walls and ceiling are paper thin. You can grind a good bit out of the floor too...but too far and you'll hit coolant so be careful on the floor.


I don't feel that the heads matter too much; if you stick w/a 195cc head or smaller, you'll be fine. The cam is the critical part for the ECM to "work right". What you need to avoid is changing the SHAPE of your tq curve, which a cam with more duration does exactly that. So, pick a cam that has close to the stock duration but more lift and/or faster ramp rates.

 

If i could afford to do an engine swap i would. I believe i mentioned that earlier in the post.

 

By the time you are done going through your list, cams, exhaust, heads, ecu tune, porting the intake, injectors, 85+ fuel pump, etc, you are not too far away from being able to do an LSx swap.

You can easily double the hp of the L83 and shave 150-175 pounds of weight off the front end.

I'm just saying you owe it to yourself to do some price comparisons.

 

OP is looking at heads (<$1k for Vortecs), flat tappet cam(~$100), porting (free), exhaust (~$1k), possibly injectors (~$100).

I'm seeing roughly $2000.00 in mods there. You can do an Gen III^ swap for roughly $2k?

 

Keeping in mind my location - I can /get/ an LS1 with 150k on the clock for 1500 bucks AUD at the very cheapest - most are 2500 and up. Plus a rebuild to be on the safe side, that's 4-500 in bits and pieces to do it myself or closer to 800 if i got a shop to do it. Then there's getting it into my car. Since there's no kits for the C4 to my knowledge, and a lot of it is custom fab work, I could either do a bad job, or take it to a rod shop for them to do it, and then be out 5 grand. So my total to do that would be 7kAUD, as opposed to less than 5 doing it the way I've been learning about so far.

On top of that, it's illegal to do engine swaps on my current level of license, so I couldn't do it for 3 more years.

I also don't just have this amount of money sitting around, I'll be buying parts as I can afford them, meaning I can't just up and get a new motor even if I wanted to.

I don't want to sound like I'm making excuses, but I have a lot of factors to account for, and the best way for me to get power at the moment is to push my current motor.

 

Super Chevy did a C4 LS swap a few years back for under 5k.

http://www.superchevy.com/features/v...hevy-corvette/

Of course if you are bound by some sort of licensing limitation it's a moot point.

I am curious as to why you are forbidden from doing an engine swap on a 32 year old car in your part of the world.

 

We have several levels of licensing here:
- Learners - Must be supervised in vehicle for a year, must not exceed 90kmh
- Provisional 1 - Can drive alone under 90kmh, lasts a year (limited to 130kW/ton)
- Provisional 2 - Can drive alone under 100kmh, lasts 2 years (limited to 130kW/ton
- Full license - can drive the full speed limit alone anywhere.

I'm on provisional 1, as I was late to get my license. Nobody on the learners or any provisional license can do an engine swap, as it usurps the power to weight vehicle laws for those licenses, and some other government bogus. As long as it's cleared by government mechanic, you can have any engine swap on your full license.

the 84 came in at 126kW/ton, so I'm barely able to legally drive it. I have all the proper paperwork with the car including a dyno sheet proving it comes under the legal limit. I do plan on skirting that law with my mods, but the government already knows it's not an LS powered vehicle. So I can't travel that path for 2 more years.

 

Thanks for clarifying that. $2k ≠ $5k.

 

I increased the fuel pressure to 15 psi and also ported and shortend the runners on intake. Changed the cam to crane 270-2s-12i roller and ran with the hyper tech chip. Heads are swapped also to 196 air flow research. If you want pics of the intake let me know.

 

I agree.

I suggested it because I know the quest for hp can be never ending. The first $2k eventually leads to another $2k and another after that.

The LS engine is much easier to get horsepower out of than than the L83.

You also do not have to use the LS engine. In my neck of the woods you can find LQ4's pretty cheaply. I've talked to guys that have done the swap in 2nd gen Camaros for under $3k.

It was just food for thought.

 

Yes please! And thanks!