I am running stock unported/unmilled GT40 irons with crane 1.7rr's and a TFS1 cam. Stock pushrods. Stock short block with 100k. I have about 2500 miles on this setup. Cam installed straight up. Valvesprings are a crane kit designed for iron heads and good for .550 lift supposedly. No dyno numbers. Self tuned. I have run 105 mph in the quarter with this setup. I have also missed shifts and banged it off the rev limiter several times. I have not heard about losing torque with 1.7's, but with 4.10's I have not noticed any weak bottom end. I ran this setup with my stock 3.08 gears for a while and it felt fine then too.

Ross

 

I ran my gt40's unported with the TFS1 cam and the stock 1.6 rockers. Ran a 13.5 @ 102 untuned the only time that combo went to the track and with a 2.4 or so 60ft (avg is around 2.1 best was 1.9 on street tires). It ran stock-ish until about 2500 then it felt like a small 50shot went off. The only reason to me it felt softer down low (below 2000-2500) was due to how much better it felt after that rpm. It still had grunt and ran well. I did have a cold idle issue, and if at a sudden stop the thing would sputter (could catch it from stalling). I think that was more due to the 24's and C&L (crap for the 94-95's) as when I got the tweecer and put the stock maf on and a j4j1 bin/cobra base file it was solid.

I ran that combo with a tmoss ported stock lower that was about as dead of a match you would think he had the heads to match them up. VERY fun combo.

 

Ryno - I've ran a TFS 1 in gt40ps with 1.7's. I too did the TFS upgrade and had valve float around 5,800's with TFS 1. I just put the stock cam in it, gained torque, and only lost 8rwhp at 5,800 RPMS (before valves floated). This was on my old 94gt. Driveability also went back to stock with the stock cam too, TFS was fine, but idle hunted sometimes, and wasn't consistent. This was with stock MAF and 19's. Before that i ran TFS heads on steeda 19 to work with the 95 gt computer i had at time, and it was also ok, idle still wasn't perfect either, the steeda 19 made for the 94/95 pickier processor really didn't help much. So long of the short, after owning a 94 AND a 95, and now owning a 90, i am going to keep the stock cam in it, and never cam a motor unless i stroke it. the driveability isn't worth it , TO ME.

Good luck brother,

Robert

 

Tuning can fix all the driveability issues

 

Thanks for the input everyone.

Ross, any valve float with your setup? What was your rev limiter set at? I have 3.55s so that's should be a happy medium between your gear experience, haha.

blksn955.o, thanks for the input. What I'm starting to think is run the 1.7s and see what happens. If anything seems odd, I put the 1.6s in and hope for the best.

Robert, thanks for your input. I was hoping you didn't mention anything about valve float, but oh well. As far as idle goes, I'm not real worried about it but I am keeping it in mind. I ended up getting my old Ecam to idle stockish, so without being too cocky, I hope I could duplicate the results with a TFS1. The reason I want to go larger than stock if I can make it work is because I already spent the money on GT40s.

Side note, tuning can fix a lot but it'll never fix a broken sensor, vacuum leak, or very poor cam selection for a given setup. So, lets not debate that and jump back on topic.

 

Going to do the crane stud conversion and add some 1.7 scorpion rockers myself. Unported the 1.7's are going to be a waste IMHO. Did a lot of research on what gt40 heads like and the TFS1 is if anything a tad on the high side of things with 1.6's. I am adding 1.7's as my heads are ported. If the heads ever come off they are getting flowed and a custom cam made. Comp also makes a good cam in on of the extreme energy models if your looking for OTS cams.

 

my old setup with gt40p heads and a tfs stage 1 cam with 1.6 rockers, cobra intake, 24#injectors and all the little bolt ons, it ran very well 303whp and 330wtq, ran 12.30 at 110mph with full interior on slicks

 

If tunes not an issue howabout the Steeda 18. I think it's the same just differnt LSA.

 

I think you should use the 1.7's but check for coil bind and make sure that you check ptv clearance. The extra lift will not hurt a thing as long as those two things are ok. Think about it this way people say that gt40 stop gaining flow above .500 lift. Using the 1.7's just keep the valve open at peak airflow longer than the 1.6's.

I personally think a better set of valve spring would not be a bad idea either. The tfs valvesprings are not quite strong enough imho. If noticeable valve float occurs at 5800 rpm it's probably happening sooner than that. I'm using some I got from thumper 460 that are drop in and set up at 140lbs of seat pressure and are good for .600 lift.

 

If your getting valve float go with a stiffer valve springs. The insurance of a stiffer springs is way better than the little Hp lost. IMO

 

Stock 1.6 GT rockers would work without issue with the TFS1, correct? I AM NOT ASKING if that is the best route, only will they work without causing an issue? I'm assuming yes.

I already own the 1.7s and could sell them if I don't use them (~$150 toward cam). I do not own any other cam right now besides a stock cam which would need to be polished before installation. It would clean with a polish (~$50). I need to do this as cheap as possible. If the 1.6s would work and I wouldn't see a big gain from 1.7s, I could sell the 1.7s and put that towards a cam. Or, I could use the 1.7s with a stock cam, but then I would wonder why I purchased new springs and GT40 heads.

I am not buying new springs again, I am going with the TFS I already have on the heads which have zero miles to date.

 

Floating the valves is dangerous. I don't know I have never used those springs I just have read the specs and I don't think they are that good for a much more aggressive than stock hydro roller. I think those springs are better suited to flat tappet cams.

Read this
http://www.summitracing.com/parts/TFS-2500100/Application/?prefilter=1
It says they can be used for rollers it didn't say they were ideal.

 

TFS valve spring kit Application Notes: Will work with hydraulic roller camshafts up to 0.520 in. lift.
If you use the stage one with 1.7s, its going to be more than .520 lift...

 

I'm kinda in the same boat

GT40P's (ported)
Cobra intake (ported)
TFS1
Crane Cobra 1.7's

None of it's assembled yet, but that's what I want to run. I'm just stumped as to which springs to get (may go with thumper's) and if i should run the 1.7 vs the 1.6. Kinda wish someone had a dyno with 1.6 to 1.7's to see what the gains/losses would be.

I wanna use the 1.7's because I already have them, but i'm not against a different cam if it will make sense with the 1.7's.

I've even debating sticking with the stock 1988 cam and just using the 1.7's in addition to the other mods.

 

I don't think the gain from 1.7's are gonna be much but if its 5hp it's more than you would have otherwise.

 

i say run it... we can bench build this motor all day long... build what you want run what you want and wish you luck.. im going unported Gt40non p heads Bcam and 1.7's.. along with a unported explorer manifold... wish me luck! alot of people out there will say the b cam is crap... yet 15 years ago it was a great cam.. and with a 150 shot can run 10's... good enough for me!

 

I assume you mean run the TFS1 with 1.7s, but you are very vague. Also, this thread isn't to debate the B cam, so how is that information relevant? Rhetorical question. Thanks for the response, but you really didn't add anything I was looking for in post 1. Do you have experience with a TFS1 with 1.7 or 1.6 rockers? If so, sorry for jumping to the conclusion that you don't.

Edit: Experience with 1.7 or 1.6 rockers and GT40 heads. Furthermore, any comparing/contrasting information which you could provide, specifically any reference to torque gain/loss?

 

ryno look at it this way, your on a budget, why risk floating a valve into a piston? That few potential HP wont look as good with a valve jammed through a piston. stock rockers+tfs 1 or stock cam + 1.7's

Enjoy the car, looks like you've got a solid plateform. I'd put the money from the cam sell / rocker sale towards a blower or better yet, turbo ;-)

 

It looks like I'm going with stock rockers and a TFS1.

RJ95, your logic makes sense. I don't really want to max out springs so stock rockers it is.

Spyder, you're right, I would probably not see any noticeable HP increase from the 1.7s with GT40 heads, plus I don't want to float a valve.

I don't want to run a stock cam with the rest of my setup, if for no other reason because I just don't want to. I got my ecam to run stock-ish and I think the TFS1 would be slightly easier.

I didn't buy the loss in torque from 1.7s and the TFS1, so thanks for backing that up.

 

It looks like I'm going with stock rockers and a TFS1.

I bought into the 1.7 rocker adds "up to" 25hp hype back in '96. The car only had exhaust, underdrives, 65mm TB and a K&N FIPK for mods at the time.

It picked up absolutely zip-squat-shat at the track. I literally mean nothing gained, no trap speed, no e.t., nothing at all. I took solace in knowing my oil was running cooler

I think you you are on the right track.

 

I'm kinda curious which setup would give more power in my situtation.

I have both the TFS1 and Crane 1.7's in my possession, so i'd like to at least use one.

With ported GT40P's and Ported Cobra intake, which would lead to more power and torque

Stock Cam + 1.7RR's (i have an '88 cam...supposedly one of the better OEM cams)
Or TFS1 + stock 1.6 RR's.

Obviously i'd rather use roller rockers over OEM rockers. Just starting to think maybe i should look into a custom cam grind to use with the 1.7's over an OTS cam.


I realize this is the 94/95 section, but i'm pretty much doing the same engine setup on my Fox