It's really hard to explain and it's even more fuzzy with people running lots of boost and high stall converters. There is a noticeable and important difference in street cars though. I've had a 408 at 11.4 to 1 that was a nitrous motor that I hurt a piston on which required taking out 0.010. At that time I decided to move to a procharger so with custom 4.040 pistons we lowered the compression ratio down to 9.5 to 1 static if I remember correctly. This was back before E85 was in common use. Car had a 3600 yank ss converter in it and I can tell you even with that converter and 400+ cubic inches the difference between 11.4 to 1 and 9.5 to 1 was huge and very noticeable in response.

Now I have a 10.6 to 1 377 that I replaced my sbe ls1 with which they are something like 10 to 1. Again very noticeable difference in response just by adding 31 cubic inches and 0.5 compression same converter 3400 pas. It's hard to explain but if you drive comparable setups with different compression ratios you'll notice the difference right away.

Here is a video I put together of some old clips I had of the 11.4 to 1 and 9.5 to 1 motor you can even hear the difference...

 

I agree on the dual pumps, I'd rather run 1 only too in the case of failure but I get that running twins or even triples is way cheaper than some of the big singles out there. W/M was for octane/cooling on both my cars and it does seem to make a huge difference even though it's only a total of an M10 nozzle on both cars and I'm not even running 50/50, just straight -20wwf which is like 30% meth. Still works like a champ.

 

To be honest I don't recall. It's been at least 7 years ago since I did the heads and cam swap. The heads are 243s that are milled a bit. (dont recall the amount) and I believe it was a stock replacement head gasket. I remember overall the compression came out to 11 to 1. Right now I am running the stock bottom end and ring gap. Only thing added to the bottom end was katech connecting rod bolts. Based on what I am hearing so far it sounds like dropping the compression down to 10.5 to 1 and having more cubes would be the way to go to have a solid street build with a decent amount of low end grunt but will scream with twin turbos.

 

Who or what is LJMS? Also do any of you guys have experience with a manual trans and turbo setup? How big of a difference do you really think id notice from having a twin setup and or a bigger single? The overall goal is to have a good amount of response down low so it still has some pep, but a lot of mid and high range power. I don't have a specific goal but i think around 900rwhp would be more than enough for the street.

 

I've done multiple 6 speed turbo setups. If the turbo is sized properly along with the hotside and tune you shouldn't have issues. More cubes will help it spool but not mandatory. I would open that ring gap up though.

 

Not someone you need to be concerned about for cam selection.

 

if you were to pick the best 6 speed turbo setup, with the best response and overall high rwhp, what setup would you pick for the money? 346 with twins, ls3 based with a bigger single?

 

I wish i had a few local cars to ride in. I know my buddy has 346 with a procharger and it is pretty boring down low and doesnt wake up until about 4k rpm.

 

What are you willing to sacrifice/remove/relocate? AC required?

 

I hardly use AC the way it is, so really anything is on the table. I'd be willing to remove relocate pretty much anything. I would say cost is the biggest overall factor. However I want to be happy with my build at the end.

 

Singles are usually cheaper and packaged easier. That said the price of turbos is much more reasonable now than in the past. Twins are definitely more difficult to package. Either way you'll want a turbo k member. If you care about low end and driving other than simply max power, cubes are your friend but it's much easier to kill a clutch or manual trans with low-end power/torque.Everything is a trade off. You can either go big cubes and less boost or less cubes and more boost. For 900whp through a stick id consider relocating the battery to the hatch and put a big single in it's place.

 

There are benefits of water in the cylinder you don't get with Ethanol blends. I'd suggest it for all setups...regardless of the CR or intercooling. Though the cost of the typical kits are a tad ridiculous. You can get a simple pressure switch, or have your ECU turn the pump on. I have less than $150 in my kits. Much less int eh Mustang and it's progressive. Though I can cheat with the MS3 a bit. The benefits for the cost are pretty amazing. Might as well "T" it and spray pre turbo and post turbo as well. Nozzles are $5, push lock fittings and hoses are dirt cheap as well. Any simple 3000 series shurflo will handle 20ish gph at 150psi or so. For a mild intercooled kit I'd suggest around 10gph of washer fluid. Its simple, easy and relatively hassle free. I haven't done any maintenance since installing my kit on the mazda. Simple on/off kit. 7gph at TB and 2gph pre turbo. With my kit on or off it affects AFR very little. To supplement fuel you'd really need alot more volume and 100% meth. Thats a whole new setup there and can get risky and expensive.

The issue I see with your pump theory is if a single pump fails with no AFR safeties setup it will cause lean issues as well. If you have AFR safeties in place and pressure safeties in place it really doesn't matter if you run 5 pumps. Though as you say I like simplicity too! My RX-7 is a single 4303. I smack it with 18v as well just to be on the safe side at higher boost levels. Also FWIW 2 AEM380s outflow a 4303 and cost about half at $130 each now on amazon.

I defiantly hear what they are saying. Going from a 8.3:1 or so 5.3 with an LS9 cam to a 10:1 5.3 with a Triple 12 cam was night/day out of boost. Engine was raspy and mean sounding compared to the "hole in the muffler minivan sound" I made previously. It was very "crisp" and would start spinning the tires well before I got into boost. I can only imagine what the LS3 at 11:1 with a healthy cam must be like. That's kinda my point though. It was too much to early. I had traction issues before I even got into boost with 275 drag radials. I just don't see the need for tons of snap down low. Also for what it's worth I got little greedy on timing and torched the deck and HG on the 10:1 5.3 setup.

 

"I defiantly hear what they are saying. Going from a 8.3:1 or so 5.3 with an LS9 cam to a 10:1 5.3 with a Triple 12 cam was night/day out of boost. Engine was raspy and mean sounding compared to the "hole in the muffler minivan sound" I made previously. It was very "crisp" and would start spinning the tires well before I got into boost. I can only imagine what the LS3 at 11:1 with a healthy cam must be like. That's kinda my point though. It was too much to early. I had traction issues before I even got into boost with 275 drag radials. I just don't see the need for tons of snap down low."

That is one of the reasons I so love turbochargers. Walk softly and carry a big stick. I am reminded of my first v8 S10 pickup. It had a vacuum leak that caused a noticeable lope in the idle that caused many to comment about how much power it must have. Would have sounded even meaner at 11:1 compared to the 8:1 compression it probably had.

 

Joe how hard do you think it would be to make that excel?

 

It'll take a while. Probably a dozen hours just to get the first working formula together. Then'll I'll have to tweak for variables.

 

Are you up for it? I'm assuming you're well versed in excel macros? If not let me know.

 

Almost all the boosted setups I build are 10-11:1 and run as high as 45psi so far. I wouldn't bother building anything less than 10:1 if it was going to be on E85.

 

Tell me more about these 11 to 1 45 psi setups? Are we talking LS 6 bolt stuff or another platform?

 

I'm also curious!

 

Aluminum 5.3 blocks with 3.785 bore. Wiseco custom pistons, Total seal rings, Callies rods, Molnar or K1 stock stroke crankshafts. 1/2" head studs, DBRods cutting ring head gaskets, TFS 220 heads and usually a HiRam or Sniper Race intake. They spin 8000rpm with BTR stage 2 or 3 twin turbo camshafts. Setups are anywhere from twin 6870 PTE or single GTR55 turbos.