Have you had this car for a while? Planning on keeping it and playing with it for several years?

 

I have had it for about 3 years, and yes this car is with me to stay. It is in very good condition, was BONE stock when I bought it, it had the factory air box and ford logo mufflers still on it.

 

Sounds like this fox is worth spending the extra coin. 11rs or bust! For a few bucks more you get a smaller cc, way better springs, 8mm stem valves, 7/16 arp studs, increased flow, and even more PTV clearance than the originals.

Add a custom stick, 9 way adj timing set and a quality steel rocker and you'll have a nice ride that will do what you want and more for years to come.

 

I think too much concern is focused on PTV with respect to comparing an 11R to the 170's. Of course it is an important consideration, but it seems to get a disproportionate amount of attention. Unless you have massive lift and/or duration, especially with a OTS cam, the chance of problems is slim. If you go with a custom cam your cam guy will design it to work with your combo.

With what you have, I'd go 170's with a custom cam.

 

11r's are a further canted head giving you more PTV clearance. It's up to you if that's worth the $$.

Why do you want to change the heads vs a turbo or blower?

 

I have a Blowzilla/Flowzilla Kenne Bell that I am in the process of selling, it is just more than I want to get into on this car. I went back and forth on whether to run it but decided to go with a good NA setup. The KB heat soak issues on these concern me, there is always the centrifugal S/C route if I ever want to go FI.
Even then, the E7 heads are not good breathers and if I were to S/C a good set of heads would go a long way in helping to take advantage of the boost.

 

Do the 11R 170s flow any better than the TW 170s? I haven't seen any flow data on the 11R 170.

 

There's more to it than flow numbers. But your intake will be a restriction on the 11R's. It doesn't have the needed runner cross section to support he 11R potential IMO.

I asked the same question about the 11R flow numbers and got this.

The 170's are this.

Not enormous differences in just flow numbers. But there are other reasons to run one head over the other. There are guys lots more knowledgeable than I that could explain why to go one way or the other. But my opinion, based on my rudimentary knowledge, is that your intake is not "big" enough for the 11R's. And it would be spending extra money for no extra gain.

 

Sounds like a nice find! Sounds like you've got the bug too. I've had my 90 vert for 17 years and have been modifying it since the day I bought it. I have the 11r 190's my only regret is not buying the 205's instead. I'd really suggest you get a 205 or bigger.

Get you some good weld in sub frame connectors on it pretty quick. Good luck and have fun!

 

My problem is I keep collecting parts and need to get around to working on it. I have a very nice set of MM sub frame connectors, in fact had them for a couple of years and need to get them installed. I am getting ready to convert over to a 5 speed, so the fun factor will be increasing for sure.

 

I could go with a different intake, but I am starting to reconsider the whole Kenne Bell thing, in fact I think that is the direction I want to go which changes most things above.

With that, the better breathing head would definitely benefit my setup but I am limited to the Cobra / GT40 lower. I can get it ported by TMOSS for the best CFM possible, but again if the lower is going to hold me back I am not sure there is much point to a bigger or better head than say the AFR165 or TW 170s. Although I imagine the boost would overcome the lower intake restriction to a certain degree.

 

If your block is stock, the KB and ported lower is going to make stock block splitting power on either head, so which head is a moot point.

 

FWIW Summit sells the 170 11R & the 190 11R street port for the same price. The 190 flows more on intake and exhaust.

The 190 "street port" and the 190 "race port" AND the 205 (which only comes one way) ALL flow the same on the exhaust No difference!

The difference between 190 "street as cast" vs "race" on the intake is only +4 cfm@.5" lift and +7 cfm@.6" lift all the low flow numbers are the same...so not much, is it worth $2100 vs. $1650??? Not for me since the exhaust is the same and I'm putting a little boost on it.

Whats funny is they are selling the 205 11R $100 cheaper then the 190 11R "race port" for $2k a pair vs. $2100 for the 190!

The 205 vs. the cheapest as cast 190 is up +3cfm@.3", +4@.4", +10@.5", +17@.6". Exhaust is the exact same.

I just bought the as cast 190 11R and they are FULLY CNC'd on all the ports, they are not "as cast" like they advertise. I also found them cheaper than Summit. $1530 delivered.

 

That's good info. Thanks for sharing that.

 

I'm by no means an expert here, but of course i like reading these threads and seeing that i'm not the only one changing my mind by month. The kenne belle set up will be more maintenance, more work to keep running without issues and the tuning will be a bit more involved....but lots of guys are and have been doing it. Just saying, if its justa fun kinda car, i'd go the simpler route....heads intake cam....you'll learn a lot about the motor. then should you still have the 'bug' for more powa slap the kenne on there.

like i said, just my 2c.

J

 

KB doesn't make that setup anymore and they are desirable.

 

Excess

 

I am of the opinion, and it may be wrong, to use the "smallest" and fewest parts possible or needed to get to a goal.

For example, I want to have a car with about 425-450 hp and lots of torque. Lots. Eight psi going into a 306 making just 300 hp (crank) will deliver. And 300 at the crank is easy to make today. Hell, it can be done with the OEM camshaft with careful planning.

My point? I think you may be over thinking it. Run the TF 170 FAC heads, the stock cam and enjoy. Regardless of what number you may make on a dyno, it would be a hoot to romp around in.

 

For a fun RPM sportscar I'd want more than 5000 rpm, and spinning one to 6k with stock heads does not count. To do that requires bigger intake and heads, the cam absolutely, and some more compression. 9:1 is low compression for high performance, hit 10:1 or don't start the project.

I personally want max acceleration, low noise(stealth exhaust and valvetrain sounds), so the blower has better potential for me. But that will almost always cost more, so each person has to plan their own parameters.

 

Not hardly any of that for the fun RPM sportscar goes hand in hand with a KB setup on our push rod engines, maybe with a Centrifugal. Low noise you may could get away with, but would depend on your boost level because they do start to make noise as boost goes up.

 

Surely you weren't having problems selling that kb setup? Were you?

 

Absolutely not, multiple people interested but decided I wanted to keep it.

 

I wish they would lower the price of the TFS 170 11R heads, Make no sense that they are the same price as 190cc heads.

 

A quick update, I did find a set of TW170 heads and have decided to stay N/A at this time. I plan on getting a custom cam from FTI for the setup.
I want to increase my compression as much as I can and would like to mill the TW170s to at least 56cc but I am concerned with PTV clearance with the stock pistons.
This bottom end still has a lot of life left in it so I am trying to avoid a full rebuild at this time.

 

I wouldn't cut the heads till you talk to Ed at FTI.

 

He said go for it

 

Personally I love NA horsepower no mater how you do it.

 

I've had slower and I've had faster but my favorite street combo in my car was:
10:2:1 306
AFR 165
Holly Upper with ported truck lower
FTI cam
Full length headers exhaust
All the supporting cast tb, pullies etc
T5 trans with 4.10 gears

Car made 332 to the tire ran 11.77 at 114 could be driven anywhere got over 20 mpg on hwy trips, drivability was excellent, it just had the right balance in my opinion (this was back in the early 2000s) it had a helluva flat torque curve power everywhere, just since you mentioned AFRs initially thought I'd post up a setup running them. I also like the TW you can make good power with either, if you are working with Ed on camshaft don't splits hairs on compression he will make sure the DYNAMIC compression is there thru timing events...