How much boost can I run if I add Methanol Injection. I currently have a 99 Z28, stock Ls1, rear mount system, running 6 lbs of boost. I was told I could increase this when i add my Methanol Injection system. At what point (boost wise) do I need to beef up my engine internals before I can safely run more.Thanks for any help

 

umm, im not an expert, im sure Jon (RealQuick) will chime in, but your pretty much pushing your limit NOW...I wouldnt mess with too much more boost as it is until you go forged and a lower compression, unless lsX motors are different and in that case ill be quiet...lol

 

i know of people with ls1's running 6-9 psi intercooled without methanol injection, though i think its just a matter of time til the motor pops. i woundnt go much past 9 psi on meth on such a high compression motor even with methanol. id say tune it, and keep a sharp eye on A/f ratios. what meth kit are you gonna be running?

 

Don't run straight methanol. Use a 50/50 water/methanol mix.

Rich

 

doh, ya should of mentioned that, by meth kit i meant methanol/water mix, windshield washer fluid has worked pretty good for my subaru and much easier to get than methanol and distilled water.

 

I wouldnt go that far maybe 9psi at the very most right now. When u do get a stronger bottom end and supporting engine components then I would stay with the same compression with the methanol/water mix. The only reason I wouldnt push more than 9psi with the stock stuff is because of the boost pressure that will destroy everything in the bottom end (even 9psi is pushing it big time) which the methanol/water has nothing to do with. That will only cool the charge and decrease detonation without snatching away much timing, not decrease boost pressure. If u can cough up the money go with some blower pistons from JE and a nice forged crank and rods then u can go as high as 16-18 or maybe a little higher with alcohol and 10:1 compression

 

best advice ^ like i said, its still a ticking time bomb, 8.5 to 9 compression would be ideal i think for 16-18 lbs. 10.1 is a tad high no? i was always told for boost its better to run more timing and less compression than vice versa because of the added cylinder pressure the boost adds ?

 

planing to use a 50/50 mix

 

use straight methanol if you can....less chance of detonation!

 

I have never used the stuff but Jose over at Alkycontrol advised me to run straight Meth, he builds a pump to do so also. I believe once you start mixing water and Meth you have to be dead on with your mix. For example if your car is tuned for a 50/50 mix and you run a 65/35 mix your looking at detonation problems meaning blown motors.
Too easy just to run straight meth, but again thats just what I hear, no experience with it.

 

too much water in the mix can make the car run lean but straight methanol should be fine, i just run a mix cause its easier to get then straight methanol for me. i just bought a used alkycontrol kit last week so ill have to do some playing between 50/50 and straight methanol

 

i wouldnt go over 10psi unless you dont mind risking things. The stock bottom end of a ls1 is much stronger than an lt car. But whats going to make or break you is the tune. I would get on a dyno if you want to up the boost.
Plus you ll get to see how much power your making. Which i would try to keep under 550-500rwhp on a stock bottom end.

 

There's been a lot of debate over what mix ratio of water to alcohol is "best" and it seems that it is up to the individual to make that determination based on tuning. But the one thing most people will agree on is DON'T run windshield washer fluid. I buy 55 gallon drums of methanol because I have a couple of alcohol injected motors, so I have an advantage of always having methanol at my disposal, but it is readily available at most "speed" shops or by shopping around on the internet. There may also be someone in your area that has purchased drums of alcohol and would be willing to sell you a few gallons at a time. It is realatively inexpensive.

 

i agree that running methanol or meth/water is best but in a pinch especially if your car is tuned for a 50/50 meth/ water mix windshield washer fluid can work. is it ideal? hell no. but ive done it with no issues for several years (using the blue stuff for -40F its actually de-icer which is the ONLY washer fluid to even consider) but it could have some thing to do with me not pushing my setup like the OP would be with a high compression motor/ high boost.you can also use denatured alcohol which is available at any home improvement store. i plan on running straight methanol for my lt1 t76 383 turbo motor

 

I talked to some representatives from turbonetics a few months back in Orlando about running a street motor with a turbo with about 11:1 with alcohol and he told me that would be risking it for the street and I should be fine with 10 or at the most 10.5:1 with proper supporting equipment. I know with blowers 10:1 is great for alcohol and high boost for the street because at 9 or 9.5:1, its a little too high for forced induction without alcohol or a big intercooler and the burning of the alcohol is not really effective at that ratio. Racing applications using straight alcohol go as high as 12.5 or 12.8:1 with no problems. Now Im not sure about the alcohol/water mix, so it might give some different results. And as for timing, for the street it probably would have to go down a bit but racing I would leave it up. With alc it allows u to run leaner than u would even with an intercooler.