Shaft Mounts for TFS 255 LS3 Heads
11-13-2015, 05:15 AM
#21
Here is a engine dyno graph showing the difference between a box stock LS3 FAST 102 vs a Holley Hi-Ram both using 90mm TB that LME had on hand. The FAST is the black lines and the Hi-Ram is the red lines.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
11-13-2015, 06:49 PM
#23
My camshaft is a HR that was spec'd with the plastic intake in mind. No use having a cam that wants to peak way past the induction systems restrictions. I like the fact that I don't have to spin it to the moon to make decent power. Did I leave some power on the table vs a good single plane setup or a sheet metal intake, no doubt. I already had the FAST LS3 setup from my previous engine combo so I wound up buying the TFS 255 LS3s.
I guess I could have upgraded to an LS7 based head and induction, but the money had to stop somewhere. I still have room for some growth since the heads are still box stock wit zero porting done to them.
If I would optimize my converter and rear gears for an all out motor pass the car would probably run some 10.20- 10.30s around 130 mph @ a 3850 lb raceweight. Right now with the tightass converter its lazy out of the hole and with the 3:73s I only cross up around 6000 rpms throught the traps. The heavy *** car rolls out pretty fair for a 93 octane pump gas compromise combo. Cant wait to hit with 150-200 shot and see what it does on the juice.
I guess I could have upgraded to an LS7 based head and induction, but the money had to stop somewhere. I still have room for some growth since the heads are still box stock wit zero porting done to them.
If I would optimize my converter and rear gears for an all out motor pass the car would probably run some 10.20- 10.30s around 130 mph @ a 3850 lb raceweight. Right now with the tightass converter its lazy out of the hole and with the 3:73s I only cross up around 6000 rpms throught the traps. The heavy *** car rolls out pretty fair for a 93 octane pump gas compromise combo. Cant wait to hit with 150-200 shot and see what it does on the juice.
Last edited by floman; 11-13-2015 at 06:56 PM.
11-13-2015, 07:45 PM
#25
Here is a engine dyno graph showing the difference between a box stock LS3 FAST 102 vs a Holley Hi-Ram both using 90mm TB that LME had on hand. The FAST is the black lines and the Hi-Ram is the red lines.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
You have to get the cam right to get the best of the shorter runner intakes. When the combo is right, I think you will find that the shorter runner intakes like the Ram and the Victor style intakes will eclipse the long runner intakes about 5500 RPM. Also, I think you will find that the Ram and larger single plane intakes will get more reward out of higher flowing heads.
Last edited by speedtigger; 11-13-2015 at 07:52 PM.
11-13-2015, 08:38 PM
#26
Here is a engine dyno graph showing the difference between a box stock LS3 FAST 102 vs a Holley Hi-Ram both using 90mm TB that LME had on hand. The FAST is the black lines and the Hi-Ram is the red lines.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
The FAST kicks it butt everywhere except for past the peak at 6400 or so. Just wanted to show a real world comparison. If you want something that fits under the hood of a 4th gen F-body without hacking the car up. To be fair, the Holley Hi-Ram does carry the power without diving down.
11-13-2015, 08:46 PM
#27
Like I said, I am sure I left some power on the table by going with my box stock TFS 255 LS3s and the LS3 FAST 102 setup. I am sure with some port work the heads would flow more. The FAST setup , I already had it and opted to use it and not hack my car up. I am sure with a single plane setup and a solid roller cam I could make more power.
That's an awesome combo you have there tigger. Will be interesting to see how it runs at the track. You are in the same boat as I am with your tight nitrous converter and nitrous friendly gears. Our cars are not set up for all out motor passes. Hope you make it to the track soon so we can see how well it does.
That's an awesome combo you have there tigger. Will be interesting to see how it runs at the track. You are in the same boat as I am with your tight nitrous converter and nitrous friendly gears. Our cars are not set up for all out motor passes. Hope you make it to the track soon so we can see how well it does.
11-13-2015, 08:51 PM
#28
That's what TB they had at LME when the engine dyno was performed. They had just put in a new dyno and that was what they had on hand at the time. The Holley Hi-Ram was just bolted on and tested just to see what the difference would be between the two intakes. We know the camshaft was spec'd for the FAST powerband. Was just a test for fun.
11-13-2015, 09:28 PM
#32
My converter is an FTI 3800 nitrous spec, but on motor I don't think it even stalls 3400-3500. The 3:73s with 28" tall tires I am only going through the lights around 6000 rpms. I am going to try a 26" tall M/T drag radial on motor and see if it will help with the tightness of the conv and also let me rpm higher through the lights.
Might have to wait till the first of the year for the spray, local track will close first part of December. I cut a 1.40 60ft with this converter on the old 6.2 engine on a 150 shot with 4.11 gears. I have since put in the 427, gained a little weight with the heavy LSX block and went down to the 3:73s.
The car is about a half second quicker and 4.5-5 mph faster on motor now. So, I hope to knock a full second off on the 150-200 shot, hoping for some 9.60s or so??
Might have to wait till the first of the year for the spray, local track will close first part of December. I cut a 1.40 60ft with this converter on the old 6.2 engine on a 150 shot with 4.11 gears. I have since put in the 427, gained a little weight with the heavy LSX block and went down to the 3:73s.
The car is about a half second quicker and 4.5-5 mph faster on motor now. So, I hope to knock a full second off on the 150-200 shot, hoping for some 9.60s or so??
11-13-2015, 09:31 PM
#33
What do your RPMs drop to on the shift and at what RPM do you shift
I am not to concerned about what mine runs n/a. It is noticeably faster than the old combo on motor and it drives way better. That is more than enough. This thing will go over 100 in 2nd gear at 7500 RPM and it gets there quick LOL. I just want it to run easy 9s on a small shot. That was the goal.
I am not to concerned about what mine runs n/a. It is noticeably faster than the old combo on motor and it drives way better. That is more than enough. This thing will go over 100 in 2nd gear at 7500 RPM and it gets there quick LOL. I just want it to run easy 9s on a small shot. That was the goal.
11-13-2015, 09:37 PM
#34
I have only made about 6 or 7 passes with the new engine. I have not done any data logging yet. I shift around 6800, I would guess it drops back around 5600-5800 rpms. The converter drives really nice and very efficient, just tight for an all out motor pass. Only slips around 6-7% I would guess.
11-13-2015, 09:44 PM
#35
That is the thing for me. This new combo drives amazing. The tight converter is really responsive on the street and the torque of the stroker is excellent. It is just plain more fun to drive than the old 6 liter and 4000 stall. If this thing lights up with the nitrous like I think it will, it is all win for me.
11-13-2015, 09:50 PM
#36
I'm kinda in the same boat. My car rips and roars on the street, will kill the drag radials at will
But, at a well prepped track where it dead hooks then you realize the tightness of the converter. Hey, mid 10s on 93 octane in a 3850 lb car is pretty cool in my book. If I can see close to mid 9s on a car I drive back and forth to the track on a small shot, hey that works for me
Good luck on the new combo, keep us all posted on your progress!
But, at a well prepped track where it dead hooks then you realize the tightness of the converter. Hey, mid 10s on 93 octane in a 3850 lb car is pretty cool in my book. If I can see close to mid 9s on a car I drive back and forth to the track on a small shot, hey that works for meGood luck on the new combo, keep us all posted on your progress!
11-13-2015, 10:00 PM
#37
The MAST Small Bore LS7s 265 would be interesting as well... price isn't much different with hollow-stem valves in there vs the TEA or BTR prepped TFS 255s. And the LS7 manifold becomes available.
The issue - I'd need to order custom pistons for the LS7 valves correct? Or would it fit the LS3 valve pocket?
Actually this is a question on the TFS 255s as well since they use the LS7 valve angle...
The issue - I'd need to order custom pistons for the LS7 valves correct? Or would it fit the LS3 valve pocket?
Actually this is a question on the TFS 255s as well since they use the LS7 valve angle...
11-14-2015, 05:05 PM
#40
It would certainly have the cross sectional area and flow for 8,000 RPM but I think the runner length of the intake manifold would become an impedance to making good power at those RPM levels.
I would look at as many Dyno graphs as I could find of N/A max effort LS7s to see where that intake tends to find peak efficiency and shoot for that as peak.
I would look at as many Dyno graphs as I could find of N/A max effort LS7s to see where that intake tends to find peak efficiency and shoot for that as peak.