The injectors fit fine in both. They go as far as they can in the rail, and as far down as they can in the intake. There the Soutbay Bosch 3 injectors. The OEM injectors, only after removing the top o-ring will it slide in enough to just barely start the threads on the studs, but even then it's extremely tight and chance of cross thread is high, not to mention it would leak without the o-ring. Even with either set on, the top of the fuel rail sits a tad above the bottom of the plenum so there is a 1/4 inch gap between the back of rail and the intake. IDK bro, I did a search on "Bosch 3 and HSR too tall", and it seems a few others have this issue as well. Of course theirs was with the holley rails not this particular setup.

 

Even pushing down as hard as I can it is roughly .070 too tall above the hole in the intake. It's also got a 1/4 gap on the backside, which a washer back there would fix that, if not it would end up being tightened against the plenum if washers or a spacer was not fabbed up of some king. The bosch 3's from Southbay are designed to sit in the OEM injectors the same way and height as the OEM injectors. However in this setup, both my OEM and Bosch 3's are too tall. The OEM's I can get them to line up only after removing the o-ring and pressing real hard. I have reamed out the holes in the rails and it helped a little but not much. Can't go any further I risk a chance of coming out the bottom of the rail.

 

I don't get it. I had no issues like that with those rails. I had plenty of space for stock injectors. without o-rings they probably would have fallen out.

 

Different injectors, same rails.

 

Have you pmd southbay maybe without there pressed on adapters they would work.

 

That's what I am curious about myself.

 

Don't get frustrated. Take a deep breath and work through it. Try lubricant on the o-rings of the stock injectors to get them in.

 

The other thought I had was is there a boss stop in the rail so the injector doesn't go in to deep. If so you can use a mill bit in a brill press to make them deeper.

 

That's perfect if you can't get the injector to move left and right. That shows a very good seal. So I don't see why you want the injector to move. Did you install the injectors with motor oil on the o-rings? With oil lubricating the rings, you can adjust the height just prior to buttoning up the bolts. My advice is to do a mock up with the HSR, rails, and intake base. Set each injector at different heights throughout the rails. The. When it's all bolted down, flip around the whole intake and see which injector is better positioned to allow full unrestricted atomization during its pulse fire. Easy fix man.

 

Ok. After reading further, you have the "updated" Bosch III's. there is a difference in your Bosch III's and my Bosch III's. I got the earlier version which doesn't have the modification. But I didn't buy mine from Southbay. I got mine from another website.

 

http://m.youtube.com/#/watch?v=XaYtP4l5A_4&desktop_uri=%2Fwatch%3Fv%3DXaYtP4l5A_4Watch 1:47 john from fic said they are 1/4 difference is southbay adapters must raise the injector. The do state on there site to contact before purchase on any manifold other than stock.

 

Yea I contacted Southbay last night and he told me the adapter is on for good. However he did say that he would exchange them for non modified Bosch 3's. So that's a win win in my book. I may just keep these modified and just buy a new set of standard bosch 3's to use on this intake and if I ever go back stock I will have the modified bosch 3's.

 

Cool man. But either way, the modded and non modded will fit on a stock intake. That's weird that the modified injectors didn't sit well.

 

Glad you found a solution. I don't like to lead people down dead end streets. But to my knowledge you're only the third person to try this setup. So your a guinea pig like Andrew and myself. Lol.

 

Hahaha. It's crazy that there are so many different problems to a common project. For example, I wanna mount the afpr on the fuel line but thought about mounting on the side if the fuel rail and the firewall too. In this case, the issue between 2 different Bosch III's designs. It's a trial and error at this point. But we shall prevail!!!! Hahaha

 

Yea unfortunately, with Southbay making their own custom adapter on the Bosch 3's they no longer fit an HSR intake. Well, unless you mill down the injector stop and the boss about .080. This would allow the injector to sit lower and allow the mount to work. Or, I could leave it like it is and just plug the current hole in the air plenum and tap a new hole a little higher. As of now I prefer my original method which is to get Southbay to swap me or just purchase an unmodified set. Good thing about getting a new set is I can upgrade to 24lbs from the stock 22lbs. This will compliment my 383 with 083 ported heads, upgraded valves and springs, 1.6 rockers,LT4 hotcam, upgraded intake and upgraded exhaust. I definitely don't want to go lean at WOT if I have a chance to avoid it in the beginning. I can always rich'n it up via tune.

So far my engine is 90% done. I have the HSR to bolt on when I get the injectors in, and she will be ready to slide down in there. I am hoping for around 400HP out of this engine with the way I built her. I tried to do everything as best I could so hopefully she screams when I want her to and is decent on fuel on the highway which was my original plan.

 

WHAT!!!!! That's very similar to what I wanna do. I currently have a stock 350 lt1 cammed block. My plan is to slap on my AFR 1040 heads, my siamesed HSR, 1.6 rr, Edelbrock TES headers and a hotcam. But the hotcam will need some tuning. I'm not saying this from experience but rather other members, especially my good friend TunedPerformance. When Tuned says or gives me advice, I won't think twice. TunedPerfomance has the knowledge and skill. I dread that I moved away from Greeley, CO. Brian and I would of been tuning chips on my IROC on a daily bases, unless my wife says otherwise.

 

I ended up mounting my fpr above the charcoal canister on the inner fender.

 

I know it is an custom mounting bracket but is the block on the bottom of the FPR a stock tpi part?

 

Yes. It is a completely stock regulator.

 

Thats good. I think I might go that route, I need to check again but I'm pretty sure I can get my hands on a stock replacement AFPR for ~$50 and I'm all about saving money lol.

Thanks for the info guys, I finally sat down and read every post on here before I commented. TunedPerformance has even jumped in on my thread to help. Gotta love the support here, its the reason I keep coming back to TGO!

 

Yea it is a stock TPI FPR. It was machined and modified by my good friend TunedPerformance. It was modified as a way to save money instead if buying a $150+ afpr.

 

Maybe my eyes are deceiving me, but any idea what modifications are done? it looks fairly normal to me.

I'm not even real concerned with it having to be adjustable, I'm just trying to figure out the best cost effective regulator before I go buying all the parts. I keep getting a bit confused though.

 

Bro, I am not gonna give you the details on how and what was done. It is up to TunedPerformance if he wants to let you in on his little project. But dont count on him giving up details. He has had one member take full advantage of his generosity. Contact him in a PM.

 

Right on man, not trying to steal any tricks. Just trying to get my car running. Did not mean to offend anyone in the slightest!

 

No secrets drill and tap

 

You'll have to forgive me. I've never actually run a tpi setup. I bought one and now I'm in the process of cleaning it up and adapting a HSR so there is a bit of a learning curve for me. I hate accidentally buying the wrong parts so I'm just trying to make sure I do it right the first time. I'll quit cluttering for now and look at the parts and see if I can draw some reasonable conclusions later and come back with intelligent questions.

Thanks guys!

 

Hey man, any question is a good question. You mentioned that you read the whole thread. So with that said, fire away with your concerns. Pardon my reply in the earlier post. I was just concerned for my friends hard work on modifying his FPR. But clearly its a green light for TunedPerformance.

 

I never said there wasn't any tricks lol, and Im not handing out bracket templates

 

I was just wondering if you modified the actual FPR in any manner, just so I could be aware not necessarily to copy it.

 

The aluminum body was modified and I had to make a tool to complete the conversion. I will offer this to any member for $50 and a discount off reprograming as a package deal.

 

Sigh... I'm about done with this HSR install... it's been nothing but a headache and money. The Modified Bosch 3's from SouthBay wouldn't work as previously discovered. So SouthBay and me exchanged PM's and we determined that I needed an unmodified injector and he recommended going to their 27lbs bosch 3 injector. So I ordered another set @ 170 bucks, waited 7 days for them to arrive from a couple states away, and wouldn't you know it... there too freaking small. Now the injector plastic bottoms out on the HSR so there is nothing holding it up so the rail is now almost 1/2" too low. I mean, it doesn't even have any resistance going down into the intake, none at all. It's almost as if the injector is too short and too thin. When I hold it up to the other injector it's roughly 1/2" shorter than the OEM injector. O-ring to o-ring comparison is close but it's still about an 1/8th to short. Also where the OEM injector goes into the intake the o-ring is big enough to start catching the bevel of the opening causing the injector to fit firmly and properly. Not the case with the new ones that came on. This injector issue, coupled with a few other issues on this HSR has burned me out. I am half tempted to rip it off, toss on my intake and carb and call it a day. Between the money I spent on the HSR, Rails, Regulator, 2 sets of Injectors, extra parts and gaskets, fittings, and time spent getting everything swapped around I could have bought a self learning MSD injection system for a little more HAHA. Ok, prolly like 800 more but still.

Just frustrated is all... had I just got a carb and intake I would have only been out less than half of what I am out on this crap and been driving it a month ago. Grrrr ahhh well. If I decide to sell this I will let you guys know if anyone is looking to get a complete setup, minus injectors since I obviously have no luck getting the correct ones.

 

Return your injectors and get your $170 back. Then grab some stock lt1 24# injectors and call it done. Simple as that. If you do decide to sell it you shouldn't have any trouble getting your money back out of it.

 

I think I got stock lt1 injectors laying around. All 8.

 

So is this a testament to the stock injectors not working with the alternative fuel rails or not fitting the HSR itself. I just finally purchased my HSR yesterday thinking I could just order some Bosch III's from southbay.

Anyone have an answer to this question lol?

 

The height of the bosch III's are the problem in this case.

 

So does anyone have a definitive answer to what will fit? I am using the holley rails because I just didn't feel like fighting my way through piecing rails together. I gotta get this thing together and running by the end of summer or I gotta let it sit for another year

So if anyone has solved this problem, feel free to chime in!

 

Have you read through this thread? I'm running lt1 24# injectors and others are using the old style Bosch IIIs. I think the ford injectors will work as well.

 

I have read the whole thing, admittedly its been several weeks, but I thought the guy above posting that he was giving up after trying both type of Bosch IIIs (modded and unmodded) and neither fit. I read other places that the unmodded fit but his post was worrying me.

Sorry to be a bother, just looking for clarification before I spend more money haha

 

This is another idea I had. I took a piece of 3/8 304 SS flared a Saginaw o-ring fitting on one side and a an-6 on the other. The rh side needs to use a threw bolt with nut and needs to be slightly elongated. If there is enough interest putting together a kit send me a pm and I will see about getting the return pieces made. The last picture shows a street and performance return an-6 adapter. no physical modifications need to be made to the fpr just one of the external clips

 

The mis-alignment issue shown in the bottom image is not a problem. There is an easy solution and this is what I did. Take the rails off and mill all 4 holes to make them slots. When you're done they will look like an inverted "U". This way you have some adjustment for different length and type injectors. I had to do it for my stock injectors removed from TPI and it works great. It allows you to also use a wider variety of injectors. I plan on using the Bosch 3rd design with my current build. No worries about them coming loose, there really isn't any tension on them. Another tip for better alignment of the axis of the injector with the CL of the injector bung, I place a thin flat washer behind the fuel rail between it and the boss on the intake base. But I would double check this first to see what thickness or even if it is necessary for your combination. I've run a slotted fuel rail for years with no issues. (If you don't have access to a mill, then careful work with a hack saw and file would suffice. Clamp it securely in a vice, lay it out and cut just inside your line. Then file to final size.)

Although this image shows a rather extreme amount of difference, I still don't think it will be a problem. The centerline of the threaded hole is well above the bottom edge of the fuel rail. If you are concerned about it coming loose you could use a small flat washer under the bolt head or even a external "star" type locking washer. You could also devise some type of lock or keeper to ensure the rails didn't move upward. But it has not been an issue for me.

If you absolutely don't feel comfortable with the slotted rail you could drill the holes in the manifold out but off set them lower. Then use a Heli-coil or other type thread insert to get back to the desired bolt thread size.

The last option would be to have the intake bungs milled a little lower. This route requires more precision work so proceed with caution. I wouldn't just start drilling them out lol. In the end it would probably be the best but it really isn't necessary.

I wouldn't beat myself up trying to get an injector that fits the rails/intake, rather make the rails/intake fit the injector. The rails you have may not have been drilled correctly in the first place. It seems odd that none of the injectors you've tried have fit. Something is off. Make it fit the style and type injector you want to use and then if you change injectors later you won't have to get a custom, one-off set of injectors made. I look for the best bang for the buck and the Bosch 3rd design are common and cheap.

 

if those are the rials i think they are , he could just do what i did with mine , i just drilled the mounting holes out to a larger size , and used lock washers

 

Yep, fundamentally the same idea.

 

jas2730, how is your Camaro holding up with the alternate fuel rails?

 

I haven't got the car running right yet. But the fuel rails seem fine from what I have seen when the car is running.

 

I got mine installed and working. I had 2 big issues, the 90 degree elbow I tried to put on the front drivers side fuel rail hit the linkage so I plugged it off and ran my crossover line in the middle instead of the front. I guess since the rails are pressurized it doesn't matter that the crossover is in the middle does it?

Other issue was the threaded holes in the bottom middle of the fuel rails wouldn't take the 3/8" NPT fittings or plugs. I brought them to my Dad for help ( he's a machinist), he told me those 2 holes were tapped 3/8" "straight" NPT instead of 3/8" "tapered NPT. He re-tapped them for me and problem solved.

Just wanted to see what you guys thought of me running the crossover across the middle instead of the front. If the rail is pressurized it doesn't matter if fuel doesn't actually flow past the front 4 injectors does it????

 

You are correct, the pressure will be the same anywhere in the fuel rail. The only time it may fluctuate is due to distribution (fluid dynamics) but I don't think it will have any impact. The only downside is now you have 2 "dead ends" where fuel doesn't pass by continuously. Not really a problem unless you run dry or disconnect for some reason, then you may have a air pocket which will have to pass through the injectors. It may stumble a bit for a second, after that you should be fine. The other possibility is trash not being flushed passed them but again it probably won't be an issue.

I ran into the same issue but chose to grind a little off the fitting and throttle cable guide to relieve the interferance. BTW the straight thread is for o-ring type fittings but as long as it doesn't leak, a plug is a plug.

 

What was the original application for Bosch III's?

Why do i see some guys using Ford injs?

Are they all OK #'s being the same. Uniform sizing?

I just received 24 lb's from FIC this week. I told FIC they we going into a Motown intake so I should be good. FIC was very helpfull answering my Q's.

 

Thanks for confirming what I was thinking. I was worried about it but couldn't decide on my own if it really mattered or not.

 

I don't know when the Bosch III's wer originally used but the one's I'm using were supplied from the factory on the 3.8l supercharged GM engine used in Pontiacs and Buicks. They are listed as 36lb injectors although some say they flow closer to 34lb. As far as Ford or other application it really doesn't matter what they were intended for as long as the length is correct, the connector is correct, the o-ring diameter is correct and they have 12-16Ohms impedance they should work. As long as those things are met get the size you need. There is a bit of disagreement as far as the pressure (esp Fords) are rated so you need to pay attention to all the specs- not just flow rate. Some have different characteristics, advantages or disadvantages and spray patterns. Spray pattern comes into play with 1 vs 2 valve heads. I choose the Bosch 3's because they have fine spray patterns and are supposed to have good "response time". Which if I understand it correctly that means they work well at high and low flow rates. Otherwise, they fit and flow the amount of fuel I need. lol