Thom

Here is the graph from a friend's 3L 8V using the LR intake, a K27/8 frame turbo (using modern BW wheels) and a 9R cam.



How much more low/mid range could anyone reasonably dream of?

This very good balance was reached using an appropriately-sized turbo and the "soft" stock 9R cam.

seattle951

How do you compare a 3.0 L with LR manifold to 2.5L with the stock manifold? You cannot.

A better test would be to compare the identical engine with both manifolds with extensive tuning to optimize for both manifolds. I am willing to bet such a test would show greater high TQ/HP at the top end for the LR manifold and better low end TQ/HP for the stock manifold. The book I mentioned had chapterd devoted to this trade-off plus specifics on how to remove turbo lag with air velocity.

Also, I am guessing that the 2.5L stock manifold would be a terrible fit for this engine because of the displacement and turbo. It was not designed for this much flow.

Thom

You precisely cannot compare both engines, and this is the whole point I want to make : do not discard this or that component and pretend it "does not work" when not put in perspective with the rest of the set up.

The stock intake was designed for a 2.5 engine using a small turbo for a max boost of ~0.8 bar, on a road engine, which is going to spend at least 75% if not more of its running time off boost. We want ram effect off boost at low/mid engine speeds to maximise fuel efficiency. Incidentally, this ram effect happens to help with spool too.

As soon as we fit a large frame turbo, we throw out of the window the balance of the factory set up since the stock intake is going to prevent any high flowing compressor to flow most efficiently in the corresponding rpm band.

There are different ways to reach the same goals.
Keep the stock intake, open up the head with a long duration/high overlap cam and you will move up the usable rpm band, but the engine will still not breathe freely up top.
Inversely, fit a short runner intake, keep a small frame turbo and a soft cam and the quick spooling small turbo will flow well enough to provide a nicely wide torque band down low, but the engine will run out of power without feeling restricted up top.
And all the countless shades of grey in between these two "polarised" set ups.

seattle951

I have a 2.5L 8v that runs 16 psi of boost at 310RWHP (Mustang Dyno). I care far more about a flat TQ curve than I do top end TQ/HP. For me, the LR manifold is a negative. I am better off with stock to improve my spool.

If Porsche and LR wanted to build a manifold for a 3L with a 27/8, what product do think would perform better? Of course Porsche has no interest in ever doing this since they would lose money. LR has found a niche that is profitable. The niche is for applications that exceed the requirement for the stock manifold. However, I am guessing there is room for improvement in the LR product, but they are limited by budget, technology and expertise. They too have to have positive ROI on their investment and there is pretty small market for this product that does not justify a huge R&D expenditure.

blown 944

Why are you such a wet blanket on the subject? It appears you're the one with mis-matched components doubting the proof Patrick has shown in evidence.

Having all the best equipment is not absolutely necessary if you have a good under an ding of the fundamentals and font mind things not being "perfect"

I know my home built intske far surpasses the stock unit. Prrfect?, no...but does a pretty darn good job.

Chris Prack

Am I the only person starting to have deja vu here? lol

seattle951

Sorry about the wet blanket. I own a consulting firm that provides product planning services to TELECOM and technology companies. I have done some work with Bosch, Ford and other companies in graduate school (full products, not components like engines). One of the things we evaluate is ROI on R&D spending. Product development is a passion of mine and the physics involved in developing intake manifolds is very, very interesting.

You deserve kudos for some great innovation and initative. i just find this topic fascinating.

333pg333

I don't take what you're saying as a wet blanket and am totally open to discourse. That's what this thread was for. I think you and Thom are saying the same thing in essence. For you and your motor, the LR intake is totally wrong. Given those circumstances I would never suggest that intake for someone with similar goals and motor. In fact I'm surprised that you bought it or was sold it? Unless 2nd hand? As Thom has shown there is at least one motor that it works well on. Not conclusive, but at least there is one satisfied customer.

For a street car I think the stock intake is fine and we've seen it live with over 500whp on some cars. As a few of us with larger bore, higher performance motors have discovered it can be a choke point in the overall scheme of things. We produced and tested this particular intake on my motor in a week. Is it a perfect design, no way. Has it provided an improvement, looks like it. :-)

seattle951

The intake manifold was part of a complete package that was sold with a new engine. I trusted the vendor to meet my goals. To address the lag we then changed the turbo to a 3076R double ball bearing and added the 6-speed. After some consultations with various vendors, the intake manifold has been flagged as the remaining lag contributor. At 310 to 350 RWHP, the stock manifold is not a huge bottleneck. When I get a chance, I plan to have it swapped out with a stock unit or might try an option from another vendor.

My point is that designing an intake manfold is a signficant undertaking. I few months back, I was reading an article about a vendor that increased TQ/HP by 8% by redesinging their component in an existing product. The company (maybe, Porsche or Ford) credited the gain to advances in computer technology that made new modelling techniques possible. The increased power of computer hardware made the new software possible.

Once again, I admire innovation tremendously and find this topic very interesting. I am sorry if I ruffled any feathers.

A.Wayne

Many pages, i must have missed the flow numbers ...


Stock Intake /Intercooler/ported head will do 500 whp on a 2.5 all day, so yes there are other means to achieve the desired goals, when such goals are quantified.


I must have missed such .........

Thom

500hp on a 2.5 8V with stock intake, in your dreams. Come up with actual dyno sheets then maybe we can discuss.

A.Wayne

Neophyte , is that you ........

refresh951

The major manufactures must design with a much more complex set of constraints which includes emissions and fuel economy. It is a lot easier to design an intake purely from a power/tq standpoint which is what most of us are doing. Modeling is great but only practical to a point. If we had access to say CFD analysis it would be ideal but the time and effort to develop a GOOD model is not really feasible. Therefore we rely on fundamental calculations that may not be the absolute best solution but can lead to improvement for sure.

Thom

Who's asking?

You're always posting like you went to the moon and back without actually supporting any of your hush hush supposed in-the-know statements, so apart from sounding like the Chuck Norris of 951 you are not bringing much to this board, sorry.

A.Wayne

It's not magic really.

Trying bench flowing the head and ancillary items. run it thru software, design camshaft , run sims and bam. pretty close to predicted results. All this 951 stuff is pretty old, alot was done a decade ago on making power out of them. Do some research instead of trying to invent aspirin.

By the way it's Bruce, not Chuck ...............



Add: Went looking for your request upstairs , stored , as 951 stuff was some years ago , i cannot post pic, something about exceeding bandwidth storage, not sure , why. can iMessage to anyone who want to put it up, heading out for track stuff shortly...

28 psi
480.34 whp
434.11 Tq

2.5 L