Engine setup ???s

[Turbovenom]

Ok, long time cobra guy and Ive been on older sites with not alot of coyote support. That being said I was pointed in this sites direction and there is a TON of info on here and some really interesting threads. However Im going on several hours of scouring and thought maybe if I just ask you may have some input.

I pulled the engine and trans (mt82) I am more than likely going to do a magnum swap as I just enjoy the stick. Car is getting an Armageddon twin turbo kit. It will be a "daily" although it doesnt get driven much. However it will see the track from time to time. I haven't really found a tuner that is reputable around me. Where this causes a problem is in the past my tuner was apart of my build, my questions are with engine setup. I only have access to 91 where I live so the main tune for daily driving will be 91 and I know that will be my hp limiter, HOWEVER I will keep E85 or race fuel on hand for when I want to turn it up I have all supporting mods good for over 1000Whp+. Before I bought the kit I was buying parts for my 4v from MMR while on the phone I asked about comp ratio they said do 10:1 it looks like keeping a 11:1 is a popular choice as was lunds suggestion. I have never dealt with Lund before but he came off kinda off putting they responded quick but hardly answered any questions and was very short/not helpfull. I then turned to Palm beach dyno who were very helpfull and informative but when it came to engine setup they said asking the builder is best, that seemed kinda odd as the tuners from what I was used to always wished people would have came to them during the build b4 they had to tune. Anyways while inquiring to MHS about assembling a short block they only want to sell a rotating assembly which is fine I assume they are swamped and dont have the time right now however they suggested a 9.5:1 compression. Honestly that is closer to what I would have thought as Im used to low comp high boost but its sounds like theese can make really good power with minimal boost. When I asked Lund why 11:1 my response was "lower comp lower hp" well yea thats true but with boost lower comp=higher boost, is it not worth it on theese motors? Like I said its street I dont want a huge lag I know higher comp will spool faster and normal non boost driving 11:1 would be great. Just seeing what others have done, experienced and can share on this.

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[K4fxd]

You are going to get many opinions.

Ford uses 9.5 on the GT500 engine. Turbos, I'd probably go 10 for better performance off boost.

 

[Jackson1320]

Just make sure you take care of all of the upgrades that are needed. Opg/CS, chain tensioners, timing chains, secondary txensioner flip bracket. Make sure you Do some research

 

[Turbovenom]

Just make sure you take care of all of the upgrades that are needed. Opg/CS, chain tensioners, timing chains, secondary tensioner flip

I've got billet opg and cs gears, I've been on a quest for what the best secondarie chain is. Any input on that without doing mmr double roller setup? Also best chains and do the tensioners themselves matter?

 

[Jackson1320]

I've got billet opg and cs gears, I've been on a quest for what the best secondarie chain is. Any input on that without doing mmr double roller setup? Also best chains and do the tensioners themselves matter?

The boss tensioners are better. The normal tensioner works on oil pressure. The boss tensioner also uses oil pressure to tighten the chain but it has a little ratchet mechanism on it so when there’s no oil pressure it will not loosen.

 

[Stephen@lethal]

You definitely want to do ARP bolts all around, don't skimp on rod bolts or studs honestly. At that level, really any compression will be fine but I went with 10.5 on my sleeved turbo 17. Also make sure whoever is building it decks and hones the block as that will be very important that a lot of people seem to pass on for some reason. Lund is a great team of guys, they will get it tuned perfectly for you. If you have any questions about parts or what to use, feel free to reach out any time. Lethalperformance.com

 

[Turbovenom]

You definitely want to do ARP bolts all around, don't skimp on rod bolts or studs honestly. At that level, really any compression will be fine but I went with 10.5 on my sleeved turbo 17. Also make sure whoever is building it decks and hones the block as that will be very important that a lot of people seem to pass on for some reason. Lund is a great team of guys, they will get it tuned perfectly for you. If you have any questions about parts or what to use, feel free to reach out any time. Lethalperformance.com

Yup main and head studs at a minimum. I have an ATI damper but there is a post on here that has about got me scared to use it but It sounds like the problem could be not getting them seated all the way. Anyways the "really any compression will be fine" I was kinda wondering what kind of boost and hp number the 9.5:1 vs the 11:1 would make not only on 91 but E85. How do you like the 10.5:1 setup? I assume the hp level out of boost is very minimal?

 

[engineermike]

I’ve written on this subject extensively on this forum, amid lots of backlash. The fact is that the compression ratio must be optimized for the fuel and will be different for 91 vs E85.

On limited octane, lower compression will allow more power before reaching the knock limit and will have lower engine stresses while doing it. Lower compression will also require more air (boost) and fuel to a achieve the same power due to lower engine thermal efficiency. You will also lose off-boost torque, 3-4% per full compression number. Egt’s will be higher but that could actually help a turbo car.

I like the 10.5/1 number and if I built an engine today for a boosted Gen3 that’s exactly the compression I would use.

That said, if you want to run 91 on a turbo setup I would like to recommend the xdi HPFP as well, which if tuned properly will allow up to 2 deg more spark timing.

 

[Stephen@lethal]

Yup main and head studs at a minimum. I have an ATI damper but there is a post on here that has about got me scared to use it but It sounds like the problem could be not getting them seated all the way. Anyways the "really any compression will be fine" I was kinda wondering what kind of boost and hp number the 9.5:1 vs the 11:1 would make not only on 91 but E85. How do you like the 10.5:1 setup? I assume the hp level out of boost is very minimal?

I loved it, made 1200whp easily on twin 6266's. Yeah you won't notice it at all, power comes on immediately.

 

[Angrey]

I’ve written on this subject extensively on this forum, amid lots of backlash. The fact is that the compression ratio must be optimized for the fuel and will be different for 91 vs E85.

On limited octane, lower compression will allow more power before reaching the knock limit and will have lower engine stresses while doing it. Lower compression will also require more air (boost) and fuel to a achieve the same power due to lower engine thermal efficiency. You will also lose off-boost torque, 3-4% per full compression number. Egt’s will be higher but that could actually help a turbo car.

I like the 10.5/1 number and if I built an engine today for a boosted Gen3 that’s exactly the compression I would use.

That said, if you want to run 91 on a turbo setup I would like to recommend the xdi HPFP as well, which if tuned properly will allow up to 2 deg more spark timing.

Yes, if you're stuck using pump gasoline, reduced compression would be the smartest option.

What's bizarre to me is the expectations that people want to make near 4 digit power and still run pump gasoline. 20 years ago we'd be talking about pretty extreme race level output, which most people would concede and necessitate some sort of upgraded fuel (race fuel).

Crazy how far we've come and the shifting baseline as to what's a lot of power and what isn't. I remember when 700 hp out of a 2V motor was pretty extreme.

I guess what I'm saying is that sticking with pump gas but wanting to make heroic power (and the need for bulletproof motor parts) is kinda like building a $100k commercial type home gym with all manner of resistance machines and free weights so you can still do yoga and ride a peleton bike.

Building a motor and insisting on 93 is like paying for a custom max'd out computer but running it on a dial up modem.

I get that some people don't have great access to E85 or don't want the headache or expense of race fuel, but that's incongruent with the idea of dropping a bunch of time and money into building a "race" engine.

 

[engineermike]

What's bizarre to me is the expectations that people want to make near 4 digit power and still run pump gasoline.

That sounds bizarre to you but sounds ideal and awesome to me. What could be better than making huge power on cheap gas, especially if you can do it with workaday reliability? Mercury Marine makes an 89 octane engine that makes 1100 hp and can do it for hundreds of hours and very high reliability. "It's easy to make a lot of power on unlimited octane." I guess some people like a challenge.

Crazy how far we've come and the shifting baseline as to what's a lot of power and what isn't. I remember when 700 hp out of a 2V motor was pretty extreme.

I totally agree. I remember being mind-blown by the 2JZ's making 700 rwhp on a stock long-block. Now we're doing it on plain gasoline. It's a great time for us, though I feel the days are numbered.

Building a motor and insisting on 93 is like paying for a custom max'd out computer but running it on a dial up modem.

I guess it depends on the goals of the user. Remember the "Pump Gas Drags", where they were running low 8's on 93 over 10 years ago? Every class has rules; it just depends on what your goals are. You could make the same argument about the modern day small-tire rules classes. Why build a race car then limit it using a small radial tire?

I get that some people don't have great access to E85 or don't want the headache or expense of race fuel, but that's incongruent with the idea of dropping a bunch of time and money into building a "race" engine.

It's definitely easier and cheaper to go fast on E85 or race gas. But if I wanted to go fast as easily and cheap as possible, I wouldn't use a modern mustang. I want everyday usability too.

 

[Angrey]

That sounds bizarre to you but sounds ideal and awesome to me. What could be better than making huge power on cheap gas, especially if you can do it with workaday reliability? Mercury Marine makes an 89 octane engine that makes 1100 hp and can do it for hundreds of hours and very high reliability. "It's easy to make a lot of power on unlimited octane." I guess some people like a challenge.



I totally agree. I remember being mind-blown by the 2JZ's making 700 rwhp on a stock long-block. Now we're doing it on plain gasoline. It's a great time for us, though I feel the days are numbered.



I guess it depends on the goals of the user. Remember the "Pump Gas Drags", where they were running low 8's on 93 over 10 years ago? Every class has rules; it just depends on what your goals are. You could make the same argument about the modern day small-tire rules classes. Why build a race car then limit it using a small radial tire?



It's definitely easier and cheaper to go fast on E85 or race gas. But if I wanted to go fast as easily and cheap as possible, I wouldn't use a modern mustang. I want everyday usability too.

Mercury Marine isn't limited to an engine bay the size of a Gen 5 mustang. Of course anyone can make a zillion HP if motor size or weight isn't a constraint. And let's not forget the COST of said gasoline monsters as well.

The entire point of blown, race fuel motors is to make the most power possible given physical constraints and goals (limited weight, economical, etc).

At some point, even race fuel taps out and guys end up throwing nitrous at it to both add power and extend the knock resistance of the fuel mixture.

I'm all for it, it's just curious to go through the process of building or ordering a custom race engine, only to leave HP on the table by not using better fuel. So you're gonna spend all that money and conscientiously not wring as much sauce out of it as possible? Again, for guys who live in BFE and can't get race fuel or E85, it's halfway understandable.

It's just a unique scenario to drop $10k+ into something and hamstring it with 93. That's all I'm saying.

 

[K4fxd]

It's just a unique scenario to drop $10k+ into something and hamstring it with 93. That's all I'm saying.

I remember when 400 HP engines needed 100 octane....

 

[engineermike]

Mercury Marine isn't limited to an engine bay the size of a Gen 5 mustang. Of course anyone can make a zillion HP if motor size or weight isn't a constraint. And let's not forget the COST of said gasoline monsters as well.

The size and cost weren't the point. The point is that it's awesome and desirable to make big power on low octane. The size and cost have a lot to do with the duty cycle and longevity of the engines. Yes, they are big and heavy and expensive, but they also make 1100 hp on 89 octane at WOT for hundreds of hours without failure. I'm not trying to fit one of those engines in a street car, though it's been done with the 93 octane 1350 hp version.

The entire point of blown, race fuel motors is to make the most power possible given physical constraints and goals (limited weight, economical, etc).

Again, take a look at every single race class out there. They are all limited by something, whether it be unported heads, minimum weight, maximum tire, fuel composition, displacement, fuel capacity, rpm, etc. In my view, limiting the fuel octane is probably one of the most practical, useful, and relatable limits you could have.

I'm all for it, it's just curious to go through the process of building or ordering a custom race engine, only to leave HP on the table by not using better fuel. So you're gonna spend all that money and conscientiously not wring as much sauce out of it as possible? Again, for guys who live in BFE and can't get race fuel or E85, it's halfway understandable.

No one here is trying to get "as much as possible" out of their engines, period. Everyone sets up their own limitations, be it cost, longevity, ease of implementation, available community knowledge base, noise level, etc. Some just choose octane as a limit.

It's just a unique scenario to drop $10k+ into something and hamstring it with 93. That's all I'm saying.

Not really. The OEMs have been pushing more and more power for decades all on limited pump-gas octane. Tens of millions have been spent to this very goal.

This is partly about perspective. Imagine this scenario: 2 cars on the dealer lot for sale. Both make 1000 hp. One of them costs $60k and runs on 93 all day every day. The other costs $50k but will only run on E85 and the range is 150 miles/tank. Which is more desirable? Which will sell more? If that doesn't bring it into focus, then all I can say is....to each, his own.

 

[Angrey]

Your comparisons are spurious and apples/oranges. The OEM's have much DIFFERENT concerns and constraints than you or I or the individual owner.

Even Dodge advertises the Demon power numbers on race fuel.

You are correct in that OEM's produce what's broadly appealing. Not much of what we do as enthusiasts is broadly appealing. We also don't have the same constraints with existing purchase contracts and relationships (with component manufacturers) EPA and NHTSA limitations and regulations, etc.

And although you're bringing up economy and range, FEW people who build an expensive, custom motor have economy anywhere near an important consideration/factor, at least not in the numbers that are on the table (if going to E85 meant 1/10th the range, it would start being a higher issue, but most people accept they're trading some mpg in exchange for other things they prioritize higher).

I've said it so many times, the biggest problem with 93 is that there is no practical way to verify the fuel's quality.

At least with E85, you can crudely test the ratio of alcohol to gasoline and get a sense of whether the fuel is acceptable.

With 93, all it takes is one bad batch to put your high hp setup at risk. And that can come from multiple harzards. Crooked fuel station owners who try to sell diluted product. "Last pump" issues with shared grades on the same nozzle. Etc.

I get that you can engineer in some slack to account for these issues (which is exactly why the OEM's give you low compression for blown products).

I concede, there are unicorns out there that want to go through the cost and effort of customized race components only to short the total output from what it could potentially be on better fuel. Somewhere there's a guy or two that says "yeah, I'd love to make even more power, but it would drop my fuel economy and range per/tank to unacceptable levels, so I'll just leave it here." You're right, it IS personal preference, I'm simply pointing out that the personal preference you're focused on is very obscure.

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