he did my base tune for my 383. it would drive ok and idle ok enough to break in the car, but your gonna really have to change alot of things to get it to run perfect naturally. WOT and heavy throttle is gonna be way off air fuel wise as in my case it was. But shouldnt be all that hard to dial it in. Mine was MAF tho and yours is SD right? MAF is alot more friendly on aggressive builds


If the heads are flowing those good numbers you've said they were in the other threads, then that cam will kick some butt! I expect it to peak around 6000 rpm, and beable to hold some power to 6500. Probly want to shift tho by 6300. Depends alittle on your advertised duration on that cam tho. Total overlap will help determine the rpm range

My cam has about the same overlap as yours and its in a 383 yet it still idles pretty good. traffic is no problem. low rpms arent sluggish or jerky at all. That cam should be pretty tame in that 427. Thats a good cam choice, you'll like it.

i personally think 2800 is abit low on the stall. even tho you want a streetable car, i think my 3600 is pretty streetable but for your car i'd think you would be happier with a 3200-3400. Just my opinion. Just tune it to lock up the converter where you want and you'll never notice that much stall til you go WOT

 

Yes, 1990 is speed density. Would you expect a problem with the stock computer?

 

oh no, my buddy has a pretty aggressive 406 running on the speed density computer and he's doing pretty good. has a 242/242 solid roller and older AFR 190/195 heads i believe and abit more compression. Miniram intake as well. ran 10.80s in a 3400-3500 lb fbody TA with a stalled auto. Now the motor is in a 94 bird and goes 11.0 at 127 with a T56 with a soft launch to save the 10 bolt rear

you'll be fine

 

With proper tuning, the stock ECM will be fine.

If I were doing this, a De Witt radiator would be on my short list. They are so purdy!

 

'85, it has the heavy duty cooling in the rpo list, but all that is gone except the oil cooler.

 

Isn't the 1990 radiator fundamentally different than 1988 because it is angled? I thought that happened in 1990 that they set the radiator at an angle to give it more surface area without making it taller.

 

Yes, in 90, they angled the radiator.

 

I would have to agree with the radiator issue. It is just good insurance. I put a DeWitts in mine and I love it.

If I had it to do again (and I will soon ), I would have ported the miniram. I believe it flows 280cfm stock. Opening it up more would be beneficial in my opinion as long as you have a good airbox/airbridge combo. I cannot get enough air to my Brodix T1's with my current set up.

You can certainly run the motor on the stock ecm but it will take some fiddling to make it streetable and you either need to have the knowledge and hardware/software or find someone who does. I went aftermarket just for ease of making changes and being able to flash right over to another tune at an instant if I want. Corky and Ski_dwn_it were running stock "style" ecms with their 434's initially I believe. Corky sold his 434 a while ago and went to a 355.

I would be careful with the initial tune. On mine, I was running way too rich and I think my rings never seated. Next time I am going to get a bench dyno to run in the motor as I think that is one of the many reasons mine has never run to it's true capacity.

 

Thanks Vader. I'm not dropping $500 for a radiator till I have to. Let's see where I fit first and go from there.

'90 was the first year of the improved cooling, that's what I thought. 89 and back had the more straight, smaller radiators.

 

It's not together yet. The Miniram will be here on the 21st. I'll take a look at it. I have the 1205 MR. They didn't want to sell the 1206 MR because they say it gets too thin on the gasket and has leaking problems.

I'm not quite sure what will be left to port....I'll take a look at it.

I need to get close, I can get a dyno tune from there.

 

Hello vacuum leak...I've got to get a vac. gauge on my car!

 

You have a 1206 MR? Since I called they took it off the website. They had it listed.

When I asked for it they said it was "unavailable" that they had 1205s. SO.......they told me they can port 1205 to 1206 FOR A CHARGE....

How absurd is that? They listed the 1206 as the same price as the 1205 but if I wanted a 1206 they'd have to port a 1205 and charge me more. Basically, the fact that their inventory didn't match the website just became my expense.

SO......I said "I'll take the 1206 for $895 as it says on the website. T

Finally they said "It was discontinued"....we never took it off the website. The walls get too thin and people had leaks.

 

Yes I do...it was bought 2 1/2 years ago from 'em. The intake to head gaskets are super thick, no clue where they came from, but I wonder about it leakin' in the rear.

 

I like the MR and think it's a great intake but it just seems that people that have really good running large SBC motors are using converted single planes.

 

Do you have a cam card with the timing events of that cam, or at least
the centerline and advertised duration?

I wanna calc the overlap, your DCR, and see how fast the ramps are.


is your .575/.585 lift at 1.5, or 1.6? Whats the gross valve lift just to be safe?

Without getting into a head debate, because I don't give a rats what brand you bought, do you happen to have 'close' flowbench output?

-- Joe

 

sorry, that lift was a typo. It's .575/575.

It's a custom grind cam. Center line is 112* Separation.

"Close" flwobench according to Dart is 300/215.

I forget what the deck is, however, the pistons are 4.125, the heads I had machined to 72CC. The static compression is 10.4 ish. No piston gave me exactly 10.5.

As we discussed I have decided to go with TPIS for the initial tune, as they have done 427s with similar setups. I have spoken to Greg at Blowerworks about doing a dyno tune, since he is local.

 

Sounds very close to my build .the only thing that i would change if i where you is the torque converter .i tried many converters and the best one i ever used was the precision industries vigilante lock up converters or the tcs converter for the 700r4.they both work excellent but the vigalante will totally impress you .

 

You should have used different heads you're leaving power on the table.

 

But no seriously That is a nice setup. The tune all comes down to who is tuning it. I have a gen 7 too but it doesn't mean SQUAT if you don't know what you're doing with it. The best thing I can say is that I love my car, and i know only I will spend the extra time here and there to iron out every little detail. If you can find someone who has the patience to do a good tune you're in luck.

 

Actually, all jokes aside when I asked AI last year about the new Dart Pro1 heads coming out for the LT1 that they had a CNC version of, he told me that they were designed more for a single plane intake with an elbow or carb, not the LT1 or Miniram.

Another reason I went with the AFRs, but I'm sure the Darts will do a decent job.

If you got a good deal on that stall converter and you're on a budget, that's cool but a vigalante 3500stall would have been very streetable and would have worked better with that cam. I have driven many Vettes and F-bodys with that converter and they felt great.