Hey guys. Please don't kill me if this is an incredibly dumb question.

Looking to have a shop built engine installed, with the prospect of adding FI later. Knowing this, I would have to use lower CR. Would this leave my car undriveable?

Again, please be gentle.

 

I would definitely not recommend doing that. It's a totally different animal when it's specifically built for low compression. Not to mention you head work for a n/a car is different than FI. In respects to timing, etc.

I would recommend doing a few things before you build your block:

A. Buy your turbo kit first. It'll cost the same as building a motor and you can run it on the stock block. You might be surprised at how much more power you can have just on the stock intervals and you might stop there.

B. If you're dead set on spending $25k for your motor and turbo install, because obviously it won't be cheap labor wise to pull the motor twice, I'd focus on the head work first, cams, port and polish, larger intake and exaust valves etc etc. Then once you can save enough money, do the bottom end the turbos at the same time. It'll save you money in the long run. Not to mention your expensive block which you risk damaging by not using it properly.

Just my $00.02.

 

That was the other option I'm considering. Would I run into too much trouble with a TT while nickel and diming my way up through supporting modifications? Is achieving 380+ whp like this realistic?

But you're right, if I were to take the plunge for an engine, I would wait until I could pay for it all at once.

 

You can do it either way. Breaking in a built motor at 9:1 with no boost will feel just like a regular stock motor. WHP loss will only be a small percentage. That said, if you're paying someone else for labor, you will save a great deal doing it all at once.

 

I see. The worst thing that could possibly happen to my car is for the engine to break, so my dilemma is whether or not I can proceed to build around the engine with FI until it comes to that point where I have the resources to plop a Stage 3 long block in there from a shop.

 

You'll will experience severe powerloss. Not just a little bit. You're car would run horribly. I've ran my evo with just a disconnected intercooler coupling and it barely ran, let alone be able to drive... He said less than 9:1 if I'm reading the title correctly. Thats more that a 20% compression loss on all cylinders. How do you think the car wouldn't loose very much power? That doesn't make much sense, no offense.

380whp? You have no need for a built block. With proper cams, fuel and management system you'll do that easily with a bolt on turbo kit to the stock block.

 

^ this is not true (see chart below). You will not experience significant power loss (less than a few percentage points) from a change in compression alone. If you put on the turbo kit and you throw a rod or spin a bearing, you could not only lose your shortblock for use as a core, but also damage your heads and turbos.

 

Well, 380 at least until I have an engine with new internals and a VBU.

 

I don't plan on using my own block due to my dislike of downtime.

So, you're saying I could potentially blow my engine at such a low level?

You two are pulling me in the exact opposite direction, haha. Still, thanks for the tips, keep them coming.

Also I saw your build thread rc, very nice.

 

Listen to rcdash. The other guy is spewing misinformation. The reason his eve ran like **** with the charge piping off is because the car was running rich as **** with the ecu being tuned for parameters.

The car will run fine IF tuned for the new compression ratio. There is no reason that the motor would miraculously explode. You have to remember fi cars drive around in vacuum under normal driving circumstances which is the same state that a na car is in.

 

Hey Chris.

I just want to be able to run a TT safely and reliably. So if I can hold off on a low CR built motor, I'd rather do that instead.

What are your thoughts on this?

 

I think Rocks ran his car with cams and low cr and had no problems. Search.

 

You're trying to tell me that putting a motor from Nearly 11:1 compression to 8-8.5:1 would run almost stock?
Have you tried this?
It would run pretty rich for one...
You would have to retune to account for the fuel
And more than likely change your timing. This is a silly argument.

And for the record there isn't a single bit of misinformation there. Simply put I said: droping a low compression short block in a car that has everything set for a higher compression motor would equal a fair amount of powerless.

Now if you want to spend the money to tune it, ie fuel and timing etc, it would run, def not efficiently though. You've inserted a chart as if it's pertaining to the question. That chart is in reference to motors built for those compression ratios for one, not just swapping a lower end out. Why would he want to do this? It's a waste of money to go that route. Secondly, where you get the chart from? I'm sure it probably has some pertainant information.

And where'd you get the impression I said the motor would "miraculously explode". That is misinformation right there. I never said that.

At 6psi, you aren't running the risk of damaging your motor and you'd be close to your 380whp that you stated. Especially on a decent tune with supporting mods.

 

Dude there is no reliability when u turbo a naturally aspirated motor. To be honest if your motor is in good shape and relatively low mileage I would just turbo the stock motor and keel the tune conservative.

 

Thanks guys, don't fight over this, though. I'm really humbled you were able to answer some of my questions though. I'd like to be able to enjoy higher than stock power before the real work begins on the engine.

However when I decide to build an engine, I'll probably go for an application specific long block.

 

READ the part where I said that IF the motor was tuned for the correct compression ratio it would run fine. Also I didn't say u said the motor would explode. If he can deal with the slight power loss then he can build the motor without the fi setup. Do I think he should do it? No!!. Just because it financially doesn't make since if he is paying someone to do the labor.

 

Greedy 18g kit on the stock motor and call it a day man!

 

Possibly, but I was looking at some of the higher end GTM TT kits. I realize that the higher A/R turbos probably won't be ideal for me on a conservative tune, but those could be replaced later?

Or can I just go all out now?

 

y not go for a lower priced kits and skip the head work. See how much money that will put you with, maybe you can get a short block then at the same time. head work not necessary and just doing that is labor intensive.

My philosophy was "do all the big stuff at one time" You're already talking about dropping the engine twice and changing turbo sizes down the road. Granted if you are doing the labor yourself or have that kind of additional income go ahead, but you've already talked about not having down time. So, I think you need to relook your goals and budget.

 

Hey man that post was my bad, I was responding to three people at once, I wasn't referring everything I said to you nor in anyway was I trying to offend. Trust me that's not my style. I was unclear to who I was responding to and that's my bad, but what's really funny is we are both basically saying the same thing. I'm just trying to give a guy some honest help and I think it's safe to say it's better cost wise to go a different route than what we were discussing. Again I appologise if you felt offended by anything I said..