I just posted about SLP runners, but as I read more on this site, I see that they are not the way to go. I plan on builing my engine to be 400+ hp, but the LTR system will not work to my advantage. So my question is,do I need to change the lower intake base and the fuel rail's when I get a SR, and where can I get this system???

 

If this thing is not emissions legal, forget it!! I will just rig up a real good LTR system, and try to get it all to match perfect

 

Stealth Ram is NOT emissions legal.
I'm happy however, because I want to see you make a good LTR system as thats my aspiration for the future of my Iroc. What will you do? I like to think it'd be something along the lines of this:

-Plenum port work (as extensive as possible)
-AS&M Siamesed Large Tubes (portmatch to plenum & base)
-Bigmouth base, ported!

It is my opinion, since noone has of yet specifically tested such a stock-tyle TPI and compared it directly to one of the big four*, that one could achieve excellent numbers that I dare to say would rival the big four*

*stealth, mini, super, and lt1 intakes.

 

I haven't dyno'd my car yet, but I KNOW for a fact that I'm making more than 400hp at the flywheel. I put 6 to 7 links on an LS-1 Trans-Am that had all the bolt-on's and thats with my motor having no tuning done yet! I have ALOT of PROM tuning to do and other misc. bugs to work out. And no, my car probably isn't emission's legal, but yes, it is naturally aspirated. My combo is in my sig. but it doesn't list all the plenum / runner / intake porting and shaping that I did. My intake setup pulls to at least 5,500 rpm's (700 rpm's higher than a stock TPI). The SLP siamese runners and some plenum porting raises where you make peak power by at least 500 rpm's. This is quite comparable to a super ram. Either way, you should be prepared to do major PROM tuning for a 400hp + TPI motor and spend the money on the parts to do it right. Hope this helps!

Mike (1bad91Z)

 

Well, now that I know the stealth ram is not emissions legal I will go with the SLP runners, fully ported, a fully ported accell base and plenum to match the runners. I will not go to far with the porting on the runners, I am going to port them about 2.5" in to start, and go from there. I am planning on dropping a supercharger on it next year, so I know I will kick down some huge numbers.

 

I would do some serious research before deciding on what length you want your runners to be. Runner length has A LOT to do with you intended HP peak and powerband.

 

Keep in mind that no matter how much porting you do, they are still LONG tube runners....and you can never get past that fact. I too would love to see big N/A numbers from a LTR setup....it looks so da mn COOL

 

LTR's.

 

I think a carefully pieced long tube setup can be an adequate intake with decent high-end. Stock TPI is nowhere near an example of what I would deem a truly superior LTR. I'm very interested in seeing how this works out for you. Keep us updated!

 

I agree you can make adequate top end with a long runner setup, but you have to look at the whole picture here. No matter how big the runners are, the incoming air still has to travel 17 inches before it reaches the combustion chamber. If you want to make serious power (n/a) the long runner setup isnt the way to go. A LTR setup doesnt really support a broad torque band, either. Its just too low-end biased.

 

What will happen when I put a supercharger on this LTR setup?? Will I still get good gains??

 

Not sure where you got your information, but that's not always correct. Longer tubes can be beneficial at making more HP, and more importantly, more than one torque peak. Do a search on the web for making your own intake manifold or similar wordings. The information is out there and with that information you can choose which intake is better for your car and driving style. Here's some math to do to help you design your own intake or at least figure out what RPM your intake is designed for...

L = ((ECD × 0.25 × V × 2) ÷ (rpm × RV)) - ½D

To compute the intake runner length (L), use the following variables:

-Effective Cam Duration (ECD) = 720° (4 cycle engine) - Advertised Cam Duration (~listed on the web for factory cam or your cam manufacturer's spec sheet) - 20° (lifter slop)
-Runner Diameter (D) = 1.5 (or so, going from memory here)
-Speed of Sound (V) = 1250 to 1300 fps, depending on temperature (use 1300)
-Reflective Value (RV) = How many times is the air going to bounce before the intake valve opens? Use 2 for LONG runners with high RPM's or 4 for short runners with moderate RPM's.
-Revolutions Per Minute (rpm) = 2500 for a good street intake, low RPM, daily driver or tow.

 

My information is based on common sense. I was refering to the TPI long runner setup and its common knowledge that it wont flow in the upper rev range. I understand the pulse wave ideas that youre talking about, but judging by his post, I was under the impression that he wants to buy an intake thats already on the market. Truthfully, there really is no LTR setup on the market that can match the power youll make with a short (MiniRam, modified LT1, etc.) or medium-length (Super Ram) runner system. Building an intake is a different story altogether, especially since he wants something emissions-legal. Im guessing that if he had the knowhow and means to fabricate an intake, he wouldnt be asking whether to buy a Stealth Ram or LTRs.

 

1bad91Z, can you give me some more specs on your heads. I am trying toput together a nice head,intake,cam, package and I am also stuck on this whole LTR setup stuff. I want a car that willplant your back in the seat from all the torque it makes but still have enough to pull to at least 5000rpms, How much more HP do you think your getting from the 5 more cubic inches?I really want close to 400 flywheel HP. I have $1,000 to spend. what runners work best with the vortec heads, and what is the cam specs

 

I'd say go Stealthram. I realize that emissions is an issue, but there are ways around that, and if you're intent on making big power (cam, heads, etc..) don't you think you'd run into emissions issues even if you had an EGR? There's more to be said about emissions than just simply having an EGR.

As for the loss in torque, how much torque do you really think you'll be losing if you lost the LTR setup? 15-20ft-lbs? Can you feel what 15-20ft-lbs is? Can you honestly say to yourself, "whoa... that lack of 15-20ft-lbs is really holding me back, I can feel this thing bogging". Proper tuning is the key here, and I believe that some members on this board have actually felt no loss of torque in the lower RPMs when they swapped over to a MiniRam. Ok, yea, you WILL lose some torque in the lower end, but in my opinion, it's negligible.

Why choke yourself off with the TPI unit? The Stealth Ram will probably be the last intake manifold setup you'll ever get, the possibilities of taking advantage of it would be a lot greater if you ever want to build a really strong engine from the bottom up.

I HAD an LTR setup, and my Stealth Ram just came in last week. If Holley had come out with the Stealth Ram a few years ago, I wouldn't even have thought of having my LTR. My only consolation is that I got my LTRs for cheap, and the baseplate was a group order special. For the amount of money that you will spend on an LTR setup (brand new), you might as well save a little more for a Stealth Ram.

The Stealth Ram is very "clean". Everything is so much more accessible (intake manifolt bolts, injectors, fuel pressure regulator). Changing an intake manifold gasket would be a breeze on a Stealth Ram as compared to an LTR setup. Need to change/replace injector(s)? Need to re-torque manifold bolts? No problem. Don't believe me? Go have a good look at a Stealth Ram installed. I have.

 

Understandable. I know he wasn't going to build his own intake, but the math will still let him figure out what RPM range a given intake works in and why.

 

If there are ways around it then none of us would be concerened with emissions. I realize that *some* people have 'ins' on bogus smog checks but most of us don't. Obviously there is more to passing smog than just having an EGR, but NOT having one is an automataic fail in many states.

 

age, thanks for that info. yes The HSR would be the last intake I would buy. I can always build up on the HSR. THe tpi only goes so far. Its just that I wont be able to get heads with the HSR right now. I guess I could havemine played with a little. Im still trying to find the right cam for the HSR that matches my gears and tranny