Awsome #'s Keep us updated.

 

SWEET!:salute:

 

This is very encouraging news. I'm about to drop a 306 with similar specs into the latest V8 Miata I'm building and would really love to see it top 300 to the rear wheels.

Here's my mix:
-1991 block overbored to 306
-TRW pistons
-Stock 1991 Mustang cam
-later design 19# injectors
-"worked" GT-40 heads from a 1996 Mountaineer
-EGR Explorer upper and lower intake
-1991 Mustang engine management
-Copper core plugs
-65mm throttle from the Explorer
-Mustang EGR spacer bored out to 65mm
-70mm Mass air created from the explorer tube and the Mustang sensor
-BBK fuel rails

Hopefully this will do as well as yours did. Thanks for posting.

-Jason

 

This is very encouraging news. I'm about to drop a 306 with similar specs into the latest V8 Miata I'm building and would really love to see it top 300 to the rear wheels.

Here's my mix:
-1991 block overbored to 306
-TRW pistons
-Stock 1991 Mustang cam
-later design 19# injectors
-"worked" GT-40 heads from a 1996 Mountaineer
-EGR Explorer upper and lower intake
-1991 Mustang engine management
-Copper core plugs
-65mm throttle from the Explorer
-Mustang EGR spacer bored out to 65mm
-70mm Mass air created from the explorer tube and the Mustang sensor
-BBK fuel rails

300RWHP will be nigh impossible with the stock HO cam. Low/mid-range will be great and the top end will be strong to 5500rpm, but, after that it's downhill quick. Degreeing the stock cam will help achieve the powerband you're looking for but 300 with the stock cam is almost unheard of. Regardless, it'll make a Miata fly.:drool:

If you really want to use a stock HO cam, try an '86-'88 stocker, they were a little better than the '89-'93s because the later cams had a change to their profiles to quiet down the valvetrain. Ford acknowledged that the change caused a 5-7HP loss in '89-'93 Mustangs that wasn't officially recognized until 1993 when they downrated the 5.0 HO to 205HP to account for numerous changes through the years (55mm MAF meter, cam profile changes, slight exhaust system changes etc.)

 

i have a 87 & 90 stock cam ill sell if anyone is looking

 

WOW, good numbers man!

Fun little street car.

 

Are you using 1.7's with your stage 1 cam? What valve springs?

 

Yes...1.7 and I put the Crane bee-hive kit on it.

 

I'm about to pull my stock heads & cam from my coupe, and toss my cobra heads & tfs stage 1 on. Did you port the GT40 heads yourself? What all did you do?

 

I did port them myself...this will give you an idea of the port work...stock valves though

 

Was this using the stock push rods? And this is on a 302 and NOT a 351w, correct?

 

Yes...stock pushrods...302

 

Here's the dyno sheet

 

Very impressive graph! Kudos to you! :salute:

 

VERY NICE !!!

 

Those are great #s for a low $ build. Nice port work btw.

 

What is the combustion chamber size? Comp ratio?

 

They were 66cc so I had them milled and they are now 62 which puts me at 9:1

 

real nice, i'm on that route as we speak, i'm curious, did you check piston to valve ? did you have to notch the pistons ?

 

Checked clearance...intake was tight but after degreeing the cam I found out why...it was at 105 so I changed it but I did not cut the pistons

 

thats odd, your graph doesn't start until about 2600rpm. any idea what cfm your ported heads flow?

 

I wanted to have them flowed but I got in a hurry to get them on.

I don't know why he started it late but I can tell you there were no tricks done like icing the itake or pulling the belt...I was not after big #'s if I was we could have taken a lot of fuel pressure out. We did 3 pulls first one was 300 added timing 305 then 306

 

here's a quick thought.. shannon and I have almost same build, and he has seen my big tank run, albeit alot of issues at track with my car other than bad driver aka me lol. Only variance really is im still speed density on stock cam. But fully ported gt40 ect. Now mine is through an AOD. But my pulls netted 235hp and 306ft. Now our tq numbers are similar but i cant see how my hp could be that much lower. And considering my baseline before top end swap was 195 to wheels at like 250 tq. My 3800lb car went best of with slipping trans (was way out of adjust after rebuild) and not being able to launch much past idle. 14.73 and 96.5. The mph in the calculators say thats roughly 265 to ground. So curious if this might be a dyno fluke, or what. Numbers just dont add up. Btw my baseline 1/4 was 16.6 at i think 87 mph. So last i checked 40 hp isnt good for almost 2 full seconds in the 1/4. I know the cam was changed on his... but tq was similar, but hp was way different from the two

Either way great numbers again shannon.

 

I have to agree with you here...........somethings definitely amiss with this guys combo; an uncalibrated dyno?? something besides the bumped compression ratio. My Cobra GT40 heads are very well ported (no flow numbers though) with a fresh valve job (stock valve sizes too) and I have an E-cam which is similar enough to the TFS-1 that there shouldn't have been THAT much of a torque/hp difference between his car and mine. Even my factory Cobra intake was ported by TMoss and also, I'm using longtubes vs. his shorties and LT's are supposed to have an advantage over shorties. I also deleted the A/c and smog from my car, another advantage over his. Mine actually has an SCT chip that is tuned lean on an A9L computer.
Basically I seem to have a good number of advantages over his combo yet I'm coming up 30hp and 25tq. short of him?? even my STD. corrected numbers come up at 286/317 and my completely uncorrected numbers at 292/320 aren't even close to what this guy has going.

 

Actually I was thinking that, and i'm not discounting your numbers at all, and yes I know there are variants in the dyno.. each strap down, air pressure, ect all effects it, but like i said my numbers just dont seem to match up right... tq is near same but hp waaaaaaaay down. And yes once i get this 3550 in, i was thinking of doing some pulls. Actually thinking of taking it to track when they open here in 4 weeks to see my numbers with the auto before i switch. I still have to finish rounding up parts before i swap tranny's which will be before the SC gets added on probably.

I was boggled by my hp numbers before if i was like 250 or so i would have figured i was ok, but as low as mine was. it was 205 on the first pull that was essentially how it was setup when you all helped me at the track. I added 6psi fuel pressure in the next two pulls and got it up to the 235. The af was at about 13.5 on first pull, 12.5 on the 235 pull.

 

Just an example on the Cobra...I made 594 with a stick put a c-4 in it...no other changes I showed 526 pump gas tunes

 

well i dont think I could truely gain 30 hp in the fuel pressure gain, with no timing change ect. But who knows.. like i said that whole visit has me boggled. I guess in the end its how fast it goes down the track all that matters...

 

Should be good for some 12.40s if she's about 3,000 lbs

 

I'm shooting for 11.84@3300lbs.... Seriously...I am hoping to hit an 11.xxx by the end of the year without getting crazy like I have with the cobra...everything is low budget...mostly old used parts even the cam was used. it needs some suspension work done so it may not do it...but that is the goal...maybe an 11.86 huh Curt

Thanks to all the non doubters....I always believe it's the little extra's that makes the difference between a good combo and a great one. Thanks again guys.

 

a "huge" variance in flow numbers of ported GT40's plus the TFS-1 cam vs. e-cam equaling a 30hp difference? Mine are ported as far as they can go without welding work by someone very experienced in porting these exact heads so our heads might be side by side as far as flow numbers go. If you read my sig you would see that I don't have the '95 computer-----my SCT chip is on the A9L computer with the Pro-M generation 1 conversion harness. I've got brand new valve springs from FRPP which are the direct replacement ones for the factory GT40 springs/E-7 springs. My peak tq. occurs about 300rpm before you, my peak hp. occurs at 5500rpm which is about 200rpm after you. I never asked the guy if he degreed my cam "straight up" or advanced or retarded it so I don't know about how my E-cam was degreed. If I had to guess, probably straight up. What ratio rockers are you using? if its 1.7's like me, the TFS will have more lift and longer exhuast duration than the E-cam which "could" explain the torque difference between our cars------but the intake duration and lift are nearly identical between the two cams with 1.7 rockers.

Just as a point of reference, I changed from an E-303 to a TFS Stage 1 in my old GT40/TFS TW coupe and with no other changes I went 2 mph faster in the 1/4 consistently - I had over 50 passes in various weather with each combo, so there's enough sample size to smooth other variables. Can't quote exact dyno results because the sheets are gone with the car but I was amazed at how much better the car felt in the low/mid and on top. I didn't think the difference would be as pronounced as it was. The intake dur./lift are similar but I think the exhaust side is where the TFS 1 has a large advantage.

 

All this bull####ting and not a mention of timing?

The tfs cam is better, noone will argue that. Top that with beehive springs, compression, cam degreed properly, and running through a good clutch id say the 30hp isnt so far fetched. Ill also mention 95 and 90 blocks have different internals, and ever setup is different and no two cars will put down the same numbers.

Why is everyone so quick to discount this guys numbers. There are plenty of 300hp gt40 slips out there.

Good for you man, nice numbers! Taking the extra time to degree, and port makes the difference, and your proof.

 

Yup! He got his stock headed/ stock cammed/ 1.7 rocker combo down to 12.80's, so this guy knows how to put together a simple combo that just plain works! With that new combo, you'll have some alum. headed guys with their tongues hanging on the ground! Congrats!

 

Maybe some of the doubters should go watch an NMRA Race and see the Factory Stock Class. It would make some believers out of people about GT40's, stock cam and good valve springs/lightweight internals. With port work bump in compression and a cam his numbers are very believable. Maybe some of the F/S Racers on here will chime in about over 300hp with this combo.

 

My son has a 27,000 original mile 85GT that he has spent the last 5 years trying to see how fast he can get it with the stock 69cc 8.4-1 heads and stock cam. He mess's with timing, carb jetting, intakes, gearing etc. His engine was built by Ford in October of 1984 and has never had the heads off or the cam out of it. It was rated at 210hp with 8.4-1 compression. He went from low 15's stock to now going 13.20's. He gets a lot of people that don't beleive him either until they watch it run. Now he's ready to put some GT40 irons on it and a cam and see what he can get it to do. It's all in getting everything on the combo to work together and then getting it all to the ground. I thnk the simple combos that are fast are the most impressive ones! He will probably beat me and I have the expensive crap!

 

93mustank was running a AFM N-41 cam with some GT40 "P"s and with a stock explorer intake etc. and he went 11.98 @ 113. That's bookin too!

 

funny....my 89 with tw heads, performer intake, full exhaust, afm n41 cam and 3.73s only trapped at 107....it think this is pretty far fetched!

 

Nice job Shannon! Very believable! Should be an easy 11.80 car with your driving. I went 11.90 at 99 mph (on the brakes) with 292 rwhp and 310 rwtq.

 

Thanks Rich! I think it's all in that 65mm TB I got from you.lol