ktm Posted January 27, 2008 Share Posted January 27, 2008 I've been doing a bit of reading on Hybridz as well as Google and have not quite found the answer I am looking for. All else remaining the same, what gains have those who have switched/ported (not just port matched) intakes seen? I know though conversations with Ron Tyler that the stock intake runners are only 55% of the intake valve open area. Increasing the runner diameter would certainly help with the VE of the intake. I am trying to determine the cost-to-benefit ratio of modifying my intake/purchasing a Lone Wolf intake manifold. I will be running up to 20 psi once I get my meth injection system installed. Presently I am running 15 psi with a T03/04E 50 trim turbo. Quote Link to comment Share on other sites More sharing options...
spork Posted January 27, 2008 Share Posted January 27, 2008 To get a little more information out there to help with your decision, maybe you should define "modifying your intake". There are quite a bit of different things that can be done such as going as far as cuting the plenum off and designing a new one and porting out the runners while you're there. What all did you have in mind? Also, what kind of head work has been done? Stock cam? All of these answers will help guide you to a decision. Quote Link to comment Share on other sites More sharing options...
ktm Posted January 27, 2008 Author Share Posted January 27, 2008 spork, I was specifically looking at either porting the runners, modifying a stock intake to use custom straight runners, or buying one of your intakes. The idea is the same - get better flow through the intake. If the runners can flow more air at the same manifold pressure, then I will see some gain. As I understand it, the runners are the restriction in the intake system and flow less air than the valves can take. I am running a P90a head. I know that gains from modifications should be looked at holistically, but unless I switch out my head to a P90 (I have one), my options are limited with the P90a. I know that there are quite a few options I can persue, my question is whether or not the gains are worth the money. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 28, 2008 Share Posted January 28, 2008 JeffP is loosing 30cfm per cylinder with the stock manifold he is using. It was extrude honed and flows significantly better than the stock one before being honed.... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted August 12, 2008 Share Posted August 12, 2008 I roughly measured the intake ports on the head and the runner diameter of the stock turbo manifold tonight. The P90A solid head that I have measures roughly 1-3/8" in diameter. The runners of the turbo intake measure about 1-1/4" in diameter. Would it be at all beneficial if I chamfered the intake runner exits out to 1-3/8" to match the intake ports on the head? I figure I can put in about a 1" deep x 1/16" chamfer at the runner exits to "bell" them out to 1-3/8". Quote Link to comment Share on other sites More sharing options...
Calgary280ZT Posted August 12, 2008 Share Posted August 12, 2008 Bo, I'm not sure how to structure a cost-benefit analysis. You'd have to have a set up with a stock manifold and dyno it, then change out only the manifold and repeat the dyno measure. As you know, I had spork port and polish a stock N42 intake. My rationale was that for $350, if it flowed anywhere close to the 270cfm per runner he thinks it flows, it would be a very good investment. But when we get my head etc. buttoned up later this week, there will have been so many changes to other parts that it will be impossible to isolate the effect of the manifold. If I were you, I'd plunk $350 down for the ported stock manifold...you can always sell it for close to that down the road if you decide to upgrade to a custom unit. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 15, 2008 Share Posted August 15, 2008 270cfm per runner on a ported manifold would outflow JeffP's currnt port which is flowing something like 220cfm at 25" at 0.500" lift. As I posted above, Jeff knows he looses 30cfm per runner, so knowing 220-30=190CFM for an extrude-honed stock diameter runner. That help, Bo? O.T. Threadjack Warning: Are you going to make the "Hot August Days" Group Z Car Show at Rickie & Ronnie's Drive in (Corner of Sepulveda and Normandie in Torrance) Saturday? 10-2? Now, back to our regularly scheduled benchracing.... Quote Link to comment Share on other sites More sharing options...
speeder Posted August 16, 2008 Share Posted August 16, 2008 Several years back I had acquired the first of the Thagard intakes and ran some datalog comparisons to a well ported N42 intake. The N42's throttle body neck was built up by welding and had a 75mm boring bar run through the opening, removing most of the bumps inside the plenum. The runners were ported to the head's port size and opened up (tapered) to about 4 inches in from the head flange. The Thagard intake used a L28 head flange with 1-3/8" straight runners and an enlarged simple square plenum, without air horns inside. The same Weber 60mm throttle body (with the manifold side tapered from 60 to 75 mm at the flange) was used on both intakes, and nothing else was changed on the engine for the comparison. At 17psi boost on a stock l28 JY bottom end and a well -worked N42 head with moderate turbo cam we recorded a 0.5 leaner AFR with the custom intake, swapped on with no tuning changes. Dr. James Thagard opined that that would translate into 25- 30 rwhp when tuned to compensate. This gain was only at the high flow regions, however - at low speeds we had evidence that the custom manifold was not as good as the ported stocker - but we decided that the top end gains made the custom piece worthwhile. I said at the time that that was a pretty cheap 25 -30 horsepower. I would expect some of the newer manifold designs seen here for L motor intakes would be even better. Quote Link to comment Share on other sites More sharing options...
ktm Posted August 17, 2008 Author Share Posted August 17, 2008 Wow, old post from the dead. Check the date guys! I intend to port my manifold this fall. Next spring I will have my spare P90 ported by Rebello. Power is addicting! I just picked up a set of 72 lb/hr injectors and will be procuring another 700 cc/min (for a total of 1400) methanol injector. Tony, I would have gone today but I had prior plans in San Diego. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 19, 2008 Share Posted August 19, 2008 blame cygnus, he dug it up! It's probably better you didn't go...there was an accident that totalled a 240 as it was leaving the venue--making a left turn a Toyota Tacoma ran the light at 50mph and took the 240 in the rf corner. It was bad. NO braking on the Tacoma at all, and the Z Driver had full on brake (it's still depressed!) Quote Link to comment Share on other sites More sharing options...
ktm Posted August 19, 2008 Author Share Posted August 19, 2008 Knowing my luck that would have been me..... That is really sad to hear. I hope that there were enough witnesses that the Tacoma driver takes it up the a**. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 22, 2008 Share Posted August 22, 2008 I only saw the accident as a result of the 'crunch' sound made during impact---I was looking the other way for traffic coming s.b. on normandie when I was pulling out. When I turned, I saw a red light above the intersection, the windshield in the air, the Z 2 feet off the ground doing a 360, and the Tacoma bouncing off into westbound sepulveda traffic, which was stopped for the light. Two other people who were in cars that witnessed it said the Tacoma ran the red light. One person in a Toyota made a statement to someone on the street, then drove off... At least two people stayed around, along with some Group Z people. I had to call his wife (8.5 months pregnant...) and let her know he was O.K. (relatively). If you want to see what happened, there is a post at ZC.C in Car Talk about 'Always wear your seat belts' that contains one photo, and a link to some photos I put up on CarDomain. Once EMT's and Sheriff arrived on scene, I went and grabbed my camera and started snapping photos. The car, as usual, is stored in my back yard now. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 23, 2008 Share Posted August 23, 2008 I hope that there were enough witnesses that the Tacoma driver takes it up the a**. Ditto. Bastards.... Another one that'll probably never come back. Quote Link to comment Share on other sites More sharing options...
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