[ATP Racing Engines]

We have been working with a fuel injection company with the system on the LTR. We have found so far that those of you who are modding your engines are running the injector to the limits of operation.

We have larger Injectors available now for the LTR. Let me know if you are interested.



ATP Racing Engines

 

[OKTRX450R]

Can you give us some more information...what do you mean by modding--Cherry Bomb/baffle out? Pipe/Intake/PIMM? In your testing what is the limit to modding?

What data do you have to show the stock injector is at its limit? Regardless of mods, if you can achieve a satisfactory A/F ratio then I would think you are not going over the limit of the stock injector...just looking for more knowledge here, thanks.

 

[hinkle]

What type of injectors are they? Stock with larger ports to flow more? Aftermarket?

 

[YFZ450 Blaster Racer]

How much will these new injectors cost?

 

[trukinjp13]

I know on the tpi or lt1 you could have a good a/f ratio but gain power with bigger injectors. I could definitely see larger injectors helping out, just look at how much more air you are getting with a intake setup,heads,cams, and then the exhaust to push it out. Now you just need bigger or ported throttle bodies.

 

[JPhelps]

Put me on the list, I'll take one.

 

[OKTRX450R]

The factory throttle body is 42mm now...I know on carb bikes Honda in particular 43mm is good for over 70HP so I do not think we are exceeding the current throttle body size.

Maybe I am just no understanding what you are saying...if you have a proper A/F ratio for max HP how is throwing more fuel going to make more power? You will alter the A/F ratio...I guess I need for you to break this down to the simple man's level for me to understand! :fro:

 

[ATP Racing Engines]

I will try to answer as much as I can. Please understand that I have spent a lot of time and money on this research to figure all of this out, so please dont beat me down for not giving you all the exact data on the injectors. In the end remember, we at ATP Racing are only trying to give everyone a better product for your money.

The stock injector was engineered for a 450cc engine (obviously) with the maximum crankshaft HP of around 65 to 70hp. That would be the high end number to run at. Now 65 Crankshaft HP relates to roughly 55 to 58 RW hp. Obviously these numbers vary so much between dynos, our main concern is to have an injector that is only working 50% as hard as it is designed for instead of 90%

Our next concern is that, in the lab where all these studies on the injector was done, the environment is as close to 100% ideal as possible. The pumps are tremedusly larger than that used in the application, the temperature is a fixed constant, ECT.

So what does this all mean? First you have an injector on and engine that is making 65 crankshaft hp, that number being near the injector limits, then add 200+ degrees of outside and engine temp, lastly, ask this poor injector to pulse properly thousands or millions of times during a race or ride

The new injectors are 8lbs larger than stock and will handle 90 to 100 crankshaft HP without maxing the injector.

This new injector will also work well with our new Billet Trottle body when it is production ready.

Hope this answers most of your questions. Let me know if there is anything else you would like to know.

Drop me a PM for pricing.

ATP Racing

 

[Rad Rob]

Have seen a C-Dale Moto-4 head that Wade Wilcox Engineering(California somewhere) did. He was actually re-angling the injector, in the head, and now has been looking into larger throttle bodies. I think the C-Dale uses a 42mm throttle body stock correct?? Maybe bigger idunno. He has a friend that works with Toyota Racing help with the re-angled injector design. This was on a Maxed out Big Bore, Big Valved, ported head.
Ahhh man here we go, welcome to the new technology, LOL

 

[ATP Racing Engines]

The factory throttle body is 42mm now...I know on carb bikes Honda in particular 43mm is good for over 70HP so I do not think we are exceeding the current throttle body size.

Maybe I am just no understanding what you are saying...if you have a proper A/F ratio for max HP how is throwing more fuel going to make more power? You will alter the A/F ratio...I guess I need for you to break this down to the simple man's level for me to understand! :fro:
[/b]

An FCR carb that is bored to 43mm is a true 43mm open hole. The LTR throttle body is 43mm, but you have a throttle shaft, butterfly and screws that are protruding into the air stream. This will take roughly as much as 2mm of FCR comparable size away from the throttle body. Our first Billet Trottle bodies will be 46mm.

Its not so much that your throwing more fuel at it, but your not running the injector on the ragged edge of its hp limits.

 

[fatv]

Good stuff ...... i cannot wait to see some dyno numbers. In theory i like what you are saying.


FUELATV

 

[Rad Rob]

Anyone know for sure if Yosh. is doing anything with the injectors on the Factory Race Quads. Or aren't they saying??? :lol:

 

[OKTRX450R]

Good stuff ATP and I like what you are saying...I would love to see some before and after dyno information.

Honest, I am not trying to bust you or anything, I just dislike information like "ours it better you need it" without any further explanation...make sense? Kinda like the power now valve or icat, etc type products not really doing anything but there add sure looks great.

Thank you for explaining what you can and I do understand you have a significant investment involved in R&D and I understand you not wanting to reveal all. I think the dyno charts can speak for themselves...hurry up already! :lol:

 

[ATP Racing Engines]

Good stuff ATP and I like what you are saying...I would love to see some before and after dyno information.

Honest, I am not trying to bust you or anything, I just dislike information like "ours it better you need it" without any further explanation...make sense? Kinda like the power now valve or icat, etc type products not really doing anything but there add sure looks great.

Thank you for explaining what you can and I do understand you have a significant investment involved in R&D and I understand you not wanting to reveal all. I think the dyno charts can speak for themselves...hurry up already! :lol:
[/b]

No ours is better than yours here, I try to stay out of that stuff, lol.

We are looking at every angle possible with this new quad for performance and reliability. This injector for example to me would be more of an upgrade for reliability than for sheer performance advantages. As I said earlier, with some of these more exotic builds, there will be a time when this will become a must. We have already run into fuel programming that pretty much maxxed out the Yosh controllers perameters in certin RPM ranges. That is why we went to the injector for information.

Plus they are not very expensive, not much more than a stock injector.

Thanks, Mike

 

[trukinjp13]

If you look at a carbuerated car Vs. a FI car the throttle body has a larger flow rate and you have a lot more fuel pressure. Carb 6.5 psi/FI 50-60psi. for fuel pressure alone. I think the billet throttle bodies will be awesome along with the injector. As long as you have a decent amount of work done to the motor, the more flow the engine will demand the more power you are going to make.

 

[ATP Racing Engines]

If you look at a carbuerated car Vs. a FI car the throttle body has a larger flow rate and you have a lot more fuel pressure. Carb 6.5 psi/FI 50-60psi. for fuel pressure alone. I think the billet throttle bodies will be awesome along with the injector. As long as you have a decent amount of work done to the motor, the more flow the engine will demand the more power you are going to make.
[/b]

Looks like you must be a drag racer! :scoot:
Saw your sig, big engine, light car = FAST, lol

 

[trukinjp13]

I like to tinker, I aint no expert but I know what works in gaining hp.

 

[OKTRX450R]

Ruffneck we have different applications in our experience with EFI...mine is in rockcrawlers and your is SPEED! I could not earlier understand your pressure #'s for FI until I realized we were talking different apps. I know the throttle body setups from GM converted into Jeeps is 8-12lb and Ford systems were 50-65. We really never had to do anything concerning speed or HP...if you stick a 350 or 351 in a Jeep or Bronco with 4-6:1 T-case and 5:13 gears not even counting the tranny reduction ratios...it has all the power it needs!

 

[trukinjp13]

Gm has a tbi system and it is real low on fuel pressure other then that they are all pretty high.

 

[OKTRX450R]

Yep...mostly off of late 80's trucks. Pretty cheap on Ebay or salvage yards and works great for RockCrawling...of course the norm now seems to be just buy a RamJet 350 and go from there. Very nice engines and come with almost everything you need.

Just a totally different world then what you are into with racing...last trip out we went up 3 stage a well known climb in our area and according to my GPS I averaged 1.4 mph!! :lol: