just been doing some reading on the vortech out of curiosity.
The hardest question i found to ask about it is
what kind of compression to go with if you build the bottom end?
finally found a few threads that answer the question! highest compression you can that will work with your cams and octane level.

SO! if one had HP goals of just under 600 HP could it be done with 91 octane 11.1 wiseco/eagle combo and a 50/50 meth setup? Or skip the meth and go for e85? (this is not a build thread, just a q n a)

does someone know of a thread that has this answered already?

 

In for answers, same question here

 

I say go e85 no meth, e85=105 octane.
You should go 9.0 or 9.5 CR on the pistons

 

I've always heard that if you are adding boost to stick with lower compression. And good luck on getting that vortech even near 500whp. Better off with turbos and e85

 

^lol. you sound soo stupid.... I was making 500whp on my vortech like 5 years ago. they are well over 650whp now.

I'd run 12:1 e85 motor with a low 15-20psi boost vortech setup

honda guys are running 11:1 on e85 with 30+psi of boost.

do some more reading, high compression on E85 is the new wave. Great off boost, enough det protection on boost.

 

good answer; so now i know it can be done....+water injection for better det protections? what would be the benefits of the higher compression for the vortech?

there are plenty of 500+rwhp sc'd z's runnin around. Low compression is great for turbos because the boost comes on early. With vortechs the boost increases gradually with the rpm's so too low compression could actually hurt the performance (for what i understand at least, could be wrong) most recommend 10.1 comp pistons if you just stick with 91 or 93 octane.

i would think going too low would kill your low end power wouldnt it?

 

the more compression that you run the more power that you make, you are for all intents and purposes forcing the same size "expolsion" into a smaller container by uping the CP ratio. And I agreee with Str8, just run straight E85 and call it a day, I have an Evo buddy of mine that is running 12:1 and 40+psi and makes just under 800...

Your right, if you go too low with your compression you will hurt lowend performance and drivability...

 

Freaking lucky for those of you guys who can run E85...there are hardly any E85 stations where I live...

BTW, if you do run E85, you will need major upgrades to your fuel setup...high horsepower (+550 whp) supercharger setups are very thirsty, much more thirsty than a typical tubro setup of the same whp...

To give you an idea, a Walbro 400, 1000cc ID injectors and a CJM Stage 2 is just enough for 600whp on a Vortech...

 

I'm doing a Vortech with E85.

DW850's, 340lph, and CJM stage 0.

Meth is for dyno queens.

 

If i may ask how much hp are you hittin on the dyno? and what compression?


ya the limit of e85 stations suck!

YES EDUCATED ANSWERS! i love these forums...

 

I had to chuckle at the 2 references.... "my Honda buddy" and "my evo buddy"

Completely, completely, completely different cars. Wtf....

Anyways I am glad to find this thread as well, I've been hunting for some specific answers to this relating to our engines. OUR ENGINES.

I was considering a 8.5 bottom end already built for my DD Vortech 10-15 PSI duties but I do fear that it's low on Compression for a Centrifugal SC.

But what if it's t-trimmed and running higher PSI? What can I expect? I would be buing the engine to keep reliability by using build internals, but if I'm losing power or have to boost like crazy to get power, then it seems like an improper step to take.....

 

I know a handful of people around town running E85 on Scooby's, EVO's and GTR's, none locally on a VQ.

The principle should be about the same, though. The SPECIFICS are something that I couldn't tell you about, though.

Definitely in for some VQ factoids related to E85 and blowers.

 

oh so i suppose theres something magical about our engine that cause them to run differently from all other 4 stroke engines? good to know glad you could tell people who already know more then enough on cars.

there isnt a ****ing thing different, some of the variable valve timing systems and the like are different but the compression works the same for EVERY engine unless its direct injected, which arnt many if any super high hp cars running that since aftermarket injectors dont exist. theres really no need for low compression on e85, its going to work the same way theres nothing magic about our engines they work the same way as every other 4 stroke engine in the world.

 

I see the reason why you ask that question because of course every car is different. But i think your not reading into the thread enough. It also takes some understanding about the difference between a sc and turbo.

Since alot of people turbo for big power all you hear on the forums is "you need lower compression". Which is alien to those who would rather have a sc because not many people have experimented with it. Why? Because dollar to power turbos will always win.

The reason why i made this thread was to answer questions like yours. You DO NOT HAVE TO LOWER COMPRESSION as long as your fuel setup is capable of supplying your engine its demand and you use the proper octane.

With turbo applications you can run a higher compression as long as you are providing the right fuel to work with what boost you want to be at and hp. Its just recommended to those who only have access to 91 and 93 octane to run lower boost. With sc you dont want to run lower compression because the boost doesnt come on all at once. At 2500 rpms you can spool a turbo to provide boost on a launch...vs and sc which will only provide a max boost at that rpm. (I know im all over the place with this im just tired from work and school today)

 

Wow someone on their cycle?



The point I was making is there's way too many variables to make a gross generalization like that. All the engines share the same principles and theory, yes, of course. But what works for one could destroy another, you can't just make a wild statement like " Car 'a' with 'b' engine does 'c' with this setup, so your car can do 'c' with the same setup too"

Using other vechicles and basic principles as a GUIDE is fine. You can't use them as a template.

IJS. Relax.
Thank you so much man, this answers my question perfectly. Much Appreciated.

 

the type of engine doesnt matter. you want the absolute highest compression your fuel can accommodate. plain and simple.

If you only have 91, then you need lower compression. If you have E85/C16, etc, you can run alot more compression.

I would run a 12:1 motor with any amount of boost from a supercharger on E85. Your boost will be limited by the tiny 6 ribbed serp belt, even if you had a big YSI charger.

When I refresh my motor, I will probably go back to 10:1 compression from my 9:1 I have now.

 

So I guess a very noob question to ask would be, why change the rod/piston at all then? Other than gaining higher rod strength and new rings, what's the point?

This makes me wonder if I'd be best just installing new rings on all the pistons checking/replacing bearings and that's it for the short block.

With proper hardware and HeadGasket of course.

 

You definitely want new rods pistons. Stock rods and wrist pins aren't up to par for that power.

High compression is the way to go! I wouldn't run an SC with anything less than 10:1. If on E85 I would go 11:1 at least.

 

I'm not going crazy on mine. This thing won't go past 350-400 whp. DD activities with rare (a couple a year) autox events.

 

Ok... another newb question (and I realize this is all likely hypothetical)

Let's assume you do a mild bottom end build for a blower (in my case, ProCharger rather than Vortech, 9psi) Bearings, forged rods/pistons, L19 studs etc. w/ stock heads/valve train.
BUT: you didn't have access to E85 every time (like if you were traveling)

Could you do 11:1, and still run one map for 93 that would be safe and another more aggressive map for E85? Or would you be setting yourself in a position to where you would have to run E85 / meth mixture only?

Oh - and second on the needing new rods/pistons. The rods especially are a weak point on the VQ for higher tq.