pipeliner

I joined this board a couple weeks ago to possibly get some help on my motor build up, but now I think I might scratch it and convert to efi. Reason being is I have no top end power and I hit a huge power lag spike for about 300-500 rpms in the middle of the band when secondarys open up. With that in mind heres what I need

1:Has to have good low end with a stock 85 cam
2:needs to be able to make power to 6200-6500rpms.

My questions are

1oes efi mean new fuel pump?
2:will port matching intake to heads kill some low end?
3:Best place to find the brains?
4:Best possible intake for this set up
5:Will I have to change distributor?


Any help would be great. This car sees no street use as tires cost to much. It only autocrosses

5.0mustang5speed

i do not think a stock 85 cam will go to 6500 and still make power
questions in order you asked them
1) yes you have to have a new pump . weather its a high out put external or a intank pump with a return
2)it may kill a little but probaly not enought to tell a difference
3)not sure what you mean as in where is it or where to get one..but a salvage has them...aslo depends what system you are wanting..like a speed density or mass air...i would go with a mass air, but the computers are different the auto and stick computer are also different so figure out what system you want, than get a conputer from a 89-93 mass air car.
4) best intake??? ask 10 people . you will get 10 different ansewars..but bbk, or gt-40 is good
5)im pretty sure you will need a injection distributor ,but i am not 100% for sure...it would nice if you can find a wrecked donor car and change all the parts..

mkspeed26

why stock cam??? EFI will cost more than it will be worth it. i bet if you get the carb tuned by a professional it will take away from the lag. a good intake for a stock cam would be a edelbrock air gap intake. you can use the stock distributor for that. if you want power in the higher rpms though i suggest a new cam and edelbrock victor jr intake (which requires a new distributor).

Quik

EFI is **** but converting over may cost a few bucks more then you want to spend. ditch that 85 cam if you want top end power or alteast retard it a few degrees to gain topend. EFI has alot of advantages but a carb can still be made usefull. IMHO carbs suck but that is my opinion.

fast83gt

Sounds like you have the wrong carb setup for your motor. How many CFM is your carb?

pipeliner

I can pull to 6400 RPMS already on a stock cam. The motor is balance and blueprinted and will turn 6500 with the stock internals


Stock cam because of Scca rules. Carb also is very well tuned as in it can handle a very high amount of G force cornering with out gasping for fuel.

Carb is stock of a 85 and is plenty big for the car. It has no lack of power and dosnt seem to run dry anywhere on the band except for when it needs those secondarys.

Quik

you can turn that motor that many rpms but thatdoesnt mean its making power up there. you can actually be over spining that cam for no apparent reason. if you wnat more topend retard that cam a few degrees

83GT306

You never said what kind of carb it was....if it's an Edelbrock or carter AFB, junk those damn Jimmy Carter carbs and get a Holley double pumper.

vfast

if this is a stock engine..than a 600 vac second. is plenty..as for the guy running 6500rpm if its with stock cam and heads you would be faster in shifting around 5500 or so.....your valve springs will thanks you for it....
there are several things to make the 600 think it's bigger like a air hone pt over the carb,mill the air horn..also changing throttle cams etc..putting in lighter or heavier spring in your secondies...buy a how to tune a holley book..

pipeliner

Already is and I had the car Dyno tuned after being built it is still pulling at 6400.


the stock carb which is a Holly and like I said is plenty of carb for the motor.

I guess I should explain the motor a little better. I was a little lean on the info, and again guys i appreciate the input keep it coming

Motor is a stock 85 longblock. Only differnces is its been balanced and blueprinted. Deck has been taken down to up compression and heads have a mild port 1 inch into ports. Distributor has been recurved. Intake is a Performer with the stock carb mounted on it with about 800 dollars in it. All carb work was done by a pro. It dynoed a couple years ago at just over 300 on both tq and hp. Now I could probably use another dyno tune but this was my reason asking to go to EFI. Again I have rules to follow per SCCA street prepared.

As for shifting at 5500 it takes time of the laps. The whole point for the B+B was to pull as much power from the widest power range I could get. If I dont have to shift and its still pulling I save time.