What kind of runner CSA should I aim for to feed a cylinder head that flows about 260 cfm? Is there a formula for figuring this out or is it a best guess kind of deal? Thanks

Call Greg Vandeventer in Yale Oklahoma.

What are you putting it on and what are you hoping for?

It's going on my 383 that has right at 10.25 compression. I have a set of pre-Eliminator AFR 190 street heads. I'm also running the ZZ9 cam from TPIS. All the reading i've done says that these intakes are a restriction, especially on the better flowing heads, so i'm just wanting to open the intake up enough to support what the heads flow. As far as what it makes powerwise, I don't have a figure in mind. It will make a little more than it does now and i'm pretty happy with the way the engine runs, so whatever it gains will be like icing on the cake. thanks

Search my threads dyno/track results on there. Very similar motor as yours and you are right..restriction indeed.

I'm currently running a freshly ported SuperRam intake. The jury is still out on the new motor with the intaker ported. My last motor (383) had the older 190cc AFR heads un touched 219 Lingenfelter cam and unported SuperRam. With around 10:5-10:7 comp. stock ECM with custom chip. Car ran very well 12.3@109. New motor, 10:7-11 comp. new comp cam 224-230 dur. .568-.571 ported 190 AFR heads and we ported the SuperRam base and cut the runners down about one inch. New motor seems to definatly have more power on the top and I don't think I lost any lowend power. Old motor was all done around 5600. I only have 200 miles on it so no times yet. My porting guy said that the base really needed porting. This is one of the early base intakes from Accel.

Tom

Just match the opening to the head port opening. That will likely be the min csa of the port and intake tract as a whole. Then open up the superram base from the head entry point to where the runner attaches as much as possible. Giving a bit of taper to the min csa section. Use as large a runner diameter as you can fit and it should go from there.

I think those heads will be a restriction from that point forward. They should support 360-375whp with a big enough cam and good intake on top.

My porting guy said he was very surprised how poorly the accel base manifold was shaped. He did a great job porting it. We also increased the size of the plenumn and shorted the runners by cutting them down around a inch. My new set up runs great with old custom chip. With the new cam and ported intake and heads I was pleasantly surprised that it runs so well. It sure feels like it pulls harder on the top than it did with old cam and head/intake combo. What are your feelings on changing to a dynamic FI ECM thats tuneable or does anyone make a larger MAF sensor for these TPI cars. I'm considering plugging in my old power processor from accel and seeing what I can do with it. I know the stock MAF is costing me some hp.

Thx,
Tom

To be honest I didnt pick up going from stock gutted MAF to a 3.5" MAF and CAI... Now I didnt spend alot of time dialing it in, just a bunch of street runs to get air fuel about same as the dyno tune on stock maf, and then went to track to verify performance. Ran about the same. Even once the stock MAF is maxed out as far as readable airflow is concerned, you can still tune around it. It doesnt take much of a motor to max out a stock MAF...thats what PE vs rpm table is for

So it sounds like your talking about some type of programmable system like, fast, dfi, something like that. when you say PE vs rpm table...sorry but whats the PE stand for? I haven't messed around with the accel power processor I have in a while, its got all kinds of tables to mess with. The system just didn't give me the drive ability I got from the stock maf. mostly idle quality was terrible. Any suggestions?

Power Enrichment/Wide Open Throttle...

I'm refering to stock OEM electronics. If your under 7k RPM and 600 hp I dont see a reason to go outside of stock electronics. Speed density from the 91-92 years is abit better for higher rpm power control but a MAF system still can produce numbers.

EBL is nice too if you dont have stock electronics but want something thats like stock electronics. I dont know much about it but seems like a great bang for the buck system.

You sound like you have some sort of piggy back system from back in the 90's. I'd just reprogram the stock ecm chip and skip the piggyback stuff

Good guy, part of the LT5 gang at Stillwater.

If this engine ran a 12.3 I would be tickeled. I think it's more than capable without the intake being ported if the prom was tuned with a laptop rather than it being mail ordered. Me learning how to tune will be on the "to do" list after it's running again.

Sounds like a plan. Should the runners be opened up to the size of a golf ball or would that be a little overkill? I read where they are something like 1.68.

Do you know or know anyone that has seen flow numbers of a complete bolted together superram intake? I have seen numbers of just the base and runners, but nothing with the plenum bolted on. I would be really curious what those numbers look like.

Just open the base inlet to whatever the runner size is. Some are golf ball sized but doesnt have to be. Larger will have less restriction

I believe a superram in stock form flows 240cfm give or take a few, bolted together. Stock TPI is in the 190-200 range I believe so there is a good gain to be had and alot more in porting.

W/Orr89

volume is where its at on the TPI intakes
Work on that turn radius also with those runners
Lid I doubt makes any difference its only 1/8 in thick maybe?
Dont sweat flow numbers or what size ball fits in there lol car will run the same without knowing

Whats ur thoughs on taking the heat syncs out of the maf sensor? I have taken the screens out. I know TPSi sells them all done up, but man they are not cheap.
Thx

The chip I have now was tuned for the older set up. I beleive the company was fast chip, I don't think they're around anymore. But they did send me 6 chips with slightly differant fuel curves. We ran all on a dyno and picked the one with the best fuel cure. The custom chips hp and tq weren't that much better than the over the counter chip I had in there, but the idle and overall drivability was much better. Suprising the car idles good and drives very well with the old custom chip. Even with the cam, head and intake modifications. I still want to try to get a more custom tune in it.

I think Ed Wright did fast chips? He should still be around. But it likely will pick up with tuning. Its hard to do any kind of mail order tune on these motors.

I wouldnt mess with the heat sinks in the MAF...too much risk in cutting those out and damaging the sensor for little or no gain. I dont think your motor is wild enough to need that done, as the stock MAF housing will flow enough to feed some serious hp.