Guess the power?

[Boss 351]

Hi all, If anyone wants to play the guessing game lol. I'm going to the dyno on the 19th to get it tuned. Want it to run on 91.

I picked up a refreshed 306 with Ecam, GT40 heads. I don't know the compression ratio, hopefully it's close to stock. Nothing fancy, no porting...

Going on top: Tubular GT40 intake, 75mm TB, 75mm MAF, 24# injectors, Novi1220 @6psi. Car has 3:73 gears, 2.5" exhaust with X-pipe with dynomax mufflers.

Car currently has over 150,000 mile engine, burns lots of oil, stock E6 heads and dynoed at 313rwhp.

 

[90fox306]

Im gonna guess around 375rwhp.

 

[85_SS_302_Coupe]

So wait, it dynoed 313hp WITH the blower or without? I'm assuming with since you have boat anchor '86 heads on it. What trans and what rear tires (street tires, drag radials, slicks?).

I too would have to say ~380hp. The heads will definitely be the limiting factor.

 

[Boss 351]

yup 313 with the 86 motor (6psi, E6 heads, 150k miles, stock cam). Street 17" tires, factory replacement clutch and T5 (may get a better clutch while it's all apart anyway).

 

[85_SS_302_Coupe]

Ok so are you swapping everything over onto a fresh 306 OR are you also adding that list of top end stuff in the first post?

If yes, then my hp guess is gonna be about the same.

If no, and you already had all that on, then it's gonna be way lower because i don't think you'll pick up much just with a freshened block if all other parts are the same.

 

[Boss 351]

what's changing

stock 86 cam to E303
E6 heads to GT40
old 302 to fresh 306*

*Note the old block is toast, burns oil like mad, foules two plugs fully after about 500 miles.

 

[85_SS_302_Coupe]

Somehow i missed the part about GT40s going on...Are they the iron production type or aftermarket aluminum?

 

[Boss 351]

From an Exploder, iron ones... not the P either... has ceramic coated shorties on the way too... Getting roller rockers for it, maybe before the tune, not 100% sure yet.

 

[85_SS_302_Coupe]

I think it should still be pushing 400hp, but then i don't really know a lot about blown motors so that's just a guess.

 

[tannerc91gt]

More than 350< > 400
there ya go.

 

[2000xp8]

If you don't change the blower pulley, the power level isn't going to change all that much.
You are going to exchange aspirated power for more NA power.

You are probably going to lose a pound or two of boost.
The supercharger is still going to be forcing the same amount of air into the engine, except their is going to be less restriction.

Remember too, when you use an SC you need more injector. Currently at 313 aspirated hp, you are close to the 24's limit.

 

[Cobra912]

I made 450 to wheels with 7lbs on a built 331

I'm gonna guess 350-360 max

 

[Boss 351]

Just a Q? Would it make a difference if I got Performer RPM heads versus the GT40. And would the difference be worth the $700 extra? I don't think so (if it's only 10~20 more HP) but just asking... Realizing that it's a setup that makes the power not each part...

 

[1989GtFoxBody]

Get yourself some Trickflow TWs.

 

[2000xp8]

Better aluminum heads are always worth it.
They will allow you to run more boost, safer.

 

[Boss 351]

It made 373HP but leaning out a little before 5000rpm... 400+ should be easy with bigger injectors and a tune. This was a baseline tune for me...

 

[88LX5.Oh]

Step up to 42's and a 9 lb blower pulley

 

[Boss 351]

Quarterhorse, 44#, 95mm MAF about to be installed

Got a 10psi pulley...

 

[88LX5.Oh]

Quarterhorse, 44#, 95mm MAF about to be installed

Got a 10psi pulley...

Keep us posted, please!! You'll be putting down great numbers I bet.

 

[NIKwoaC]

Very nice!