In the process of rebuilding my '87 TPI 350. It's been run in the past with many mods, heads, cam, ported intake, etc...I'm looking at the need for more intake flow. I wasn't looking to go to SD, so I'm looking for an alternative to a stock or Wells MAF sensor to achieve more flow. I'm running about 350hp now and am looking to get at least 400 with this stroker rebuild and intake change. I have heard that you can go to a Ford MAF with a different harness, however, I'm not sure how involved that changeover is or how expensive. Cost is a major concern here.
If there is a way to change the intake and also go the SD way with a limited budget, I would love to know about it. I also burn my own chips......

Any thoughts would be helpful.

Thanks,
Chris

 

???

 

You realize that a MAF is less or a flow restriction than a stock 48mm TB, right? And that a 48mm TB can support 500+ HP on the Ramjet 502? And that only 4 little 7/8" diameter holes in the restrictor plates under the carb on a Nascar 358 can still make 725+ HP, right? (Watch that happen in Florida tomorrow. )

You may determine that the MAF is a restriction, but the math doesn't necessarily support that. Still, if you find that there is a restriction, you can use about any MAF you like, provided you can scale its output from whatever it happens to be to a 0-5VDC linear analog signal. A MAF translator or simple op amp and output transistor could be breadbhoarded to accomplish that very thing. The unfortunate part is that the stock ECM can only register between 0 and 255 grams/second of incoming air in closed loop mode, and all other flow above that has to occur in open loop or the mixture will begin to go lean.

 

Thanks for the response. Was only interested because there seemed to be an improvement in performance with the stocker I had in there after a removed the screens and fins...

Thanks,
Chris

 

There is little doubt that you may be able to improve WOT air flow by removing screens and the cooling fins, but there may also be a trade-off. The most significant problem is at the upper end of the engine flow ranges and before the TPS gets to 80% (4.0V). Under that condition, yoiu can get a very lean mixture before the ECM goes open loop and allows a richer mixture. The struggle of the ECM will be between the O² input and MAF input, which will never be read any higher than 255g/S.

 

The issue that I'm having is that with all the mods, SLP runners,ported plenum, 220/230 .510" lift roller cam, roller rockers, TF 23 heads, prostreet 700r4, 2800 stall, shorty headers and dynomax 3" cat back, Crane ignition,30lb injectors,AFPR, stock TB w/airfoil, stock TPI base, custom chip by ME with altered ARAP bin,,,the car only runs low 14's with 3.73 gear. Something is really wrong somewhere and I'm not sure where. I'm in the process of tearing down the motor and installing a 5-spd trans. I want to go with a slightly larger cam, 230/240 with less than .540" lift and a centerline of 112 instead of the 114 I have in there now. I also want to change the muffler from the superturbo Dynomax to the Ultra Flow that's a straight through design. There is no CAT conv. on the car.

Any thoughts let me know, but there is some(alot) HP missing somewhere. Maybe the cam is just too small or my chip needs tweaked some more. I've spent lots of hours on it with very minimal improvements.

Thanks,
Chris

 

all that for a low 14? I dont think thats a lack of horsepower, i think thats a lack of tune. I dont want to get into the "well my car runs a so and so and it only has this, this and this" kind of thing her but with all that your time should be much lower. Maybe its your combination of parts thats wrong (not saying it is because i have no clue)

 

I went as far as removing the TPI setup and running a carb and performer RPM intake that I altered to fit the TF heads. It ran better, maybe 25hp more. I just think that the cam is a little small based on the better flowing intake setup and heads and that, combined with the need for more tuning, may do the trick. Right now the car seems like it's running about 320hp or so at the flywheel. Just basing that on what some vettes were running 1/4mile at the track. I'm just running out of ideas and it seems like the cam may be just a little short on the intake duration side.

With the carb on there, the motor pulled much better to about 6200 instead of the limited 5500 with the TPI setup. I'm looking at going with the HSR to add some top end....This is the only injected car I've got and it's been a chore trying to tune it. My other cars run carbed small and big blocks. It's been a learning experience over the last few years.

Thanks for your input too,
Chris

 

What is your MPH?
48mm to small as is stock TPI intake to get max power from that set-up,remember the intake on the TPI needs to be modded as a whole to gain most benifits.That is a solid 12 sec set-up you have tuned right.
A 358 nascar engine makes 700hp because it revs to 9 grand...rpm=hp...anything revved high enough will make decent power.

A 48mm on a ram jet 502 is choking that motor big time....500 hp on a 500 cubic motor is sad to say the least.

 

Thanks also. My mph is 97-98. This is with no tire spin and a 1.7 R/T. 12-second means running about 400hp or so. With that cam 220/230 @.050 =276/290 adv., I think I'd be hard pressed to get near that 400hp mark. I'm just not sure if the issues completely lies in the tuning. I do know that the stock base needs replaced to see a more modest gain in hp. As soon as I re-ring the motor, I'm probably going a little larger on the cam side and replacing the intake. I'll do some tuning then hit the track again with the new setup and manual trans.

Thanks again,
Chris

 

The parts you have on right now(with a bigger TB/ported base)should support an easy 12 second time...97-98mph is a tad better then a stock L98...no offense of course, but you have a lot of power yet to be tuned from that combo. The cam you have in now is actually a decent size for a 350 long runner set-up. The 230/240 is more idea for the stealth-ram. You said that you need to re-ring the motor...perhaps a bottom end problem is costing power too.

BTW you don't need 400hp to run 12's...especially on a TPI set-up..There are several guys on here running 12's(with long runner set-ups) making around 300 To the wheels~350-360 flywheel...TPI is about great launches taking advantage of all that low end power... Good luck

 

If I could get this sled down the 1/4 in 12's, I would love to know how. Does anyone have an ARAP bin their running with a similar setup??? I've re-burned my chip at least 100X with no improvement. I don't really know where else to go other than stick in a bigger bumpstick and replace the intake. I'm not sure if 3" exhaust would slow me down that much, but traxion did mention once that a straight through muffler yields a much better result than a chambered one like the super turbo. I don't think the bottom end of the motor is a problem at all. compression was great in all cylinders, however there was a small oil consumption issue because the moly rings I was running never really seated that well. any other ideas please let me know.

Thanks.

 

I have one, but I dont know how much better it'd be than yours. Can you send me your bin file and I will look at it and see if I see anything unusual?

Was running near the same cam myself, with stock base, runners, and vette heads and was able to run a best of 13.6@104 with no traction at all, in a G-body. Stepped up a bit on the cam and did a head swap, and I thought traction was bad before The computer is extremely upset with this change as well I might add.

First few times out with the car before any tuning it was running 14.2's@97-98.

 

I'll email you my bin. I used tunerproRT and the PP2. I can add another few degrees in there, but then it runs a little worse and knocks on occasion.
I can spin the big meats on the back a little in 1st and that was about it. I've tried all different combos of timing and fuel and finally said the heck with it and tuned it for fuel efficiency in around the town driving. She's been sitting nearly a year now and I've finally got some time to put her back together. Waiting on my rings and bearings. There is one thing to note. With the 700r4 in the car and the car in neutral and on jack stands, it was very, very hard to even spin the rear tires by hand. Not sure if that's normal with that type of trans. I spent $1100 on a prostreet rebuild 4 years ago and it has always been that way.
With the manual in there right now, the car has not been run with that trans yet, the rear tires are easy to turn. Maybe that means nothing, but I'll sure find out once the motor is back in and the cars on the street. Hopefully a few weeks only now. Let me know if you get the email.

thanks a bunch.
Chris