Boosting my Lude need an exhaust

[Rob]

Well, its going to be a slow build but I am planning it now so I can get all the parts that I need. I was wondering if there is an exhaust system for our Preludes w/ turbo. I looked for GRedddy and their EVO TT and nothing available. Will the EVO2 any others work okay with a medium to hi boost and not affect its performance?

[twokexlv6coupe]

unfortunatly there aren't any BOLT-ON exhaust systems for our cars with turbos. the smallest size piping you should go with is 2.5", with 3" piping being optimal, but there aren't any bolt-on systems with piping that big.

your options, if you want either 2.5 or 3" piping, is either a custom mandrel bent system, or buying the kteller weld-on system where you can chose your own resonator/muffler combo.

[Rob]

So it's best to go with 3" all the way? Man I already drag speed bumps at stock height,:mad:

All well the price we pay.

[lilbluelude]

you could be running a 4" exhaust... welcome to my world.:sadwavey:

[Rob]

twokexlv6coupe,

So I hear you are the one to ask about boosted Ludes.

Well I am about to start an engine build for going turbo, I'm getting the block re sleeved. I have a question about getting the deck closed. My buddy I am helping build a SR20 for his 240 SX said I should have the deck closed. I guess that is some kind of insert that covers the holes by the sleeves? Will that prolong the motor or hurt more than leaving that alone and leaving the deck open?

Also I am getting a kit that can run up to 25 psi, I know that is alot I'm more of having it run around 15 - 18 psi. For that I wanted to know about my compression I know I have to bring that high H22A4 compression down but by how much? I was thinking around 9:1 but would 8.5:1 be better?

This is going to be a massive build, pistons, rods, I think I am going to use the stock crank, unless I hear differently. Head is going for a total valvetrain upgrade (turbo cams probably Skunk 2), metal head gasket if I can find one.

I wanted to find out some pointers, so this won't be a trial and error mission that would be way too exspensive, so I thought it best to talk to a Turbo Veteran. Thanks

[lilbluelude]

my names not twokexlv6coupe, but I might be able to help ya out. Just depends on what you want. No offense to him, but hes never built anything that i know of and Ive got more than a few builds under my belt.

Its not nessecary to close the deck by any means, but there are differing opinions on the matter. If you like, they make an item called a 'block guard' that is basically what you are refering to. If it were my motor I would run one for the increased piston travel speeds and the fact they are pretty cheap.


Compression is an interesting topic as well. You can run anything from 7:1 to 12:1 compression and boost your motor fine. Most people run lower compression because they fear detonation issues and hear say has alot to do with it. Personally, I reccomend running from 9.5-10.5:1... I like 9.5:1 compression because you can easily find pistons and its a great compromise for your everyday normal boosted vehicle It all depends on your goals. The higher your compression is, the more power you will have out of boost and in boost. This is a double edged sword as well though, the higher it is the more issues you can have with detonation.


Use the stock crank as theres no point in doing otherwise. 100% need to have the entire bottom end balanced though. The stock headgasket is metal and works well. Cometic also makes a nice headgasket and thats another option for you. The good part about cometic is they offer gaskets in different thicknesses and bore sizes depends upon your needs and wants.

[Rob]

Okay thanks for the advice, I think I will start a post on the build once I start, so can I call on you when I get stuck? Thanks again.

[Si Speed]

my names not twokexlv6coupe, but I might be able to help ya out. Just depends on what you want. No offense to him, but hes never built anything that i know of and Ive got more than a few builds under my belt.

Its not nessecary to close the deck by any means, but there are differing opinions on the matter. If you like, they make an item called a 'block guard' that is basically what you are refering to. If it were my motor I would run one for the increased piston travel speeds and the fact they are pretty cheap.


Compression is an interesting topic as well. You can run anything from 7:1 to 12:1 compression and boost your motor fine. Most people run lower compression because they fear detonation issues and hear say has alot to do with it. Personally, I reccomend running from 9.5-10.5:1... I like 9.5:1 compression because you can easily find pistons and its a great compromise for your everyday normal boosted vehicle It all depends on your goals. The higher your compression is, the more power you will have out of boost and in boost. This is a double edged sword as well though, the higher it is the more issues you can have with detonation.


Use the stock crank as theres no point in doing otherwise. 100% need to have the entire bottom end balanced though. The stock headgasket is metal and works well. Cometic also makes a nice headgasket and thats another option for you. The good part about cometic is they offer gaskets in different thicknesses and bore sizes depends upon your needs and wants.

What's your preference on water/meth injection on these high boost applications?

[lilbluelude]

What's your preference on water/meth injection on these high boost applications?

Im not exactly sure what your looking for here... I'm a huge fan of meth/water injection and it cant hurt any application out there... High boost works great and helps cool the motor very well.. We all know the more stress you put the motor under with higher boost also puts in alot more heat in the equation. It doesnt replace the need for an intercooler, but it sure helps put out the performance desired in all aspects.

[hardwhite]

would there be any noticeable gains on a low boost application?

[lilbluelude]

it all depends on how you use it and whats its setup to do as to how much. Thats the simple answer.

Basically, water injection is great for any application at all. The problem is that it requires you fill it up and that takes extra effort. Essentially, water injection will help cool the intake charge (air after turbo is hot), reduce detonation, reduce exhaust temperatures, and actually steam clean the engine all in the process... Thats a 100% win situation no matter what!

Methanol is where it gets tricky. Methanol is a fuel just like gas. It burns hotter, but outputs less heat to the surrounding areas than gas. Methanol does alot of the same things as water, but its 100% an octane booster to the tune of 108-116 octane.. YOU must tune for methanol, but the benefits are great.

When tuning with methanol/water injection: You can run super aggressive timing and not worry about detonation. You WILL make extra power from the timing your running. You also will make power from the cooler (denser air) going into your engine and the methanol/water burning(fuel and steam) just helps out in the power!




For your application of low boost, you will see great benefits because during tuning you can really get the most out of every psi and everything the motor will give you very safely and repeatable. Why not go with a kit that sprays while in boost? Its an extra $300 or so, but its a very nice mod. Heet is windshield washer fluid sold at walmart that is methanol and water. Cheap and easy. You can run just water injection and see the benefits of lower temps and steam cleaning. You will be able to run more agressive timing, but not as much as a mix with methanol. Just another thing to think about. Look at the article I link lower down. Theres some graphs that should make you smile and probably better explain what you will see...







GM used meth/water injection in the 60's... It just had a bad outcome because it would blow motors when you ran it dry and ragged on it. Thats my warning and hopefully it makes you want to research some things if you like the idea. Im hooked for life and the bandwagon is growing. I wrote an article on preludepower on it a while ago. It goes much farther in depth.
http://preludepower.com/forums/showthread.php?t=257481&highlight=methanol


Keep in mind I run it on my prelude. My sig explains alot. Im running 93 octane gas too. I run a 2.5 gallon tank and fill it up every 800-1000 miles or so. Thats not alot and is very very cheap for the gains I get.