If I am adding Alky to my car, will larger injectors make a differece? I have stock turbo, 264/264 cams, down pipe, full exhaust, Upper/lower IC, hks intake, fuel pump, and forge bov. Adding O2 housing, alky kit, and possibly 10.5 hotside.

 

more info needed

 

updated

 

any answers

 

i would say no. But then again, you should run an egt to see if you're running lean.

 

you shouldnt need bigger injectors when spraying alky because you end up taking out fuel to accomadate for the alky.

 

I was thinking the same thing but wasn't sure. The reason I brought this up is because there is an Evo. with about the same mods. I have putting down 400whp and the only real difference is bigger intercooler and injectors.

 

It shouldnt have any effect due to the injector size although the intercooler helps a decent amount. this "evo" your speaking about probably has more mods than you think, or the dyno it was on wasn't set properly... could be a million things that could differ 400whp to some others with 350whp. To hard to say without all the same variables.

 

I would highly recommend injectors if you have cams and a full TBE. We have seen close to 90% duty cycle with these upgrades. Another thing you have to consider is with the increase in horsepower, you will need to compensate with more fuel. Larger injectors will be a cheap insurance vs blowing a motor with lack of fuel.

We have tested the Helix Denso 720cc injectors with good result. It idles just like stock and its easy to tune. You might want to look into those since the price is good. Only $365 shipped on our site.

Thanks,
Tom

 

FWIW, the stock 550cc/min injectors will support 380bhp at a conservative BSFC of 0.55 lb/hr/bhp. Injectors are typically rated at 85-90% static flow to give a margin of safety, so you'd see a bit more than that figure before they are done. Furthermore, disc type injectors run more efficiently at higher duty cycles.

If methanol is used to get the additional power, a 7gph nozzle will account for ~15-20% of the total fuel load at max power (at 380-400bhp), which reduces the load on the injectors by a significant margin.

In short, upgraded injectors shouldn't be a necessity if you're going to throw methanol into your present configuration to get more power. Of course, it's never bad advice to recommend considering an upgrade when approaching the limit, but where that limit occurs depends not only on the power levels, but also the tuning (AFR).

A handy calculator: http://www.z31.com/software/injector.pl

As for injector brands, my personal favorite are Lucas injectors, which IMO are unbeatable with respect to price vs. performance ratio. A short writeup as to why they outperform the typical Bosch/Denso design can be found here: http://www.turbosaturns.net/articles/injectors.htm

Just FYI.

 

Thanks man! That is very useful info.