Dynamometer Results & Comparisons - TRex results with stock heads

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)

has anyone every tried spraying a cam like this off the line with maybe like a 3600 stal or so. jw.
nice numbers btw

nice numbers, I got 410 with a 224/224/581/581 112LSA on stock heads I'm happy with my numbers

very sick. some people make those numbers with big cams and ported heads. :)

Very impressive numbers! :cheers:

"but it seems to die after 6700 or so"

6700 or so?! This isn't something I'd lose any sleep over. :drive:

...but it seems to die after 6700 or so. I would look at those heavy ass rockers. They're probably robbing you precious rpm. My little 215 cam bangs the rev limiter at 6800 hard. I'm running the lightweight stock rockers though. That's what Thunder recommends.

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)


Bad Ass! :headbang:

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)

Ur rockers as stated above are too heavy, and its probably costing u a little power as well as rpm. That cam screams up to 7k and wants more :chug:

I would only run stock rockers.

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)

You made 393/390 with the ASA cam? Sweet!
Oh, yeah, nice TRex numbers. Put some stock rockers back on there and see if your upper RPM die off goes away. That cam should be pulling harder up to 7K, though the Thunder info does show it peaking at 6700. Hmm.

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)

Are you running hyraulic lifters or solid? If you are running hydraulic, then I would say your lifters are floating at 6700 rpm which might explain the drop off. Also, are those dyno numbers using a 10-bolt or 12-bolt?

I'd say that's not the case. Especially since lifters don't float. The valve springs cause the floating.

Ditched my ASA cam, and went with a TRex. Ditched the SLP longtubes, and got some Dynatech 1 3/4 to 1 7/8's headers, and added some harland sharp rockers. With the other basic bolt ons, pulley, k&n fipk, ls6 intake, ported TB, and true duals... i pulled..

427rwhp/398rwtq... pretty happy with it, but it seems to die after 6700 or so. Will be putting an LSX 90/90 on it shortly, and removing the k&n fipk and putting on a regular lid setup. This is with bone stock heads (they are 01 heads though, but untouched) and an otherwise bone stock engine. :drive: Not quite what Thunder got, but im still happy :)

What are the specs from the TRex? Who did or where did you get the ported TB from. I have heard that Shanner?? is a good TB. Are you true duals the x pipe style?
Got lots of questions cuz I was just getting ready to go with LS1 stage II heads flowing 305 on the IN and 260 on the EX. I am guessing you already have LS6 heads? Mine are the LS1 in my '00 WS6. Was gonna match it up with a cam with 240-260 dur 112-114 lobe @ 550 lift.

I think he meant hyd. pump.. oil building up in the lifter.. not allowing the valves to close al the way.... the reason people go to solid roller setups... by I could be wrong.

Nice #'s too by the way.

What are the specs from the TRex? Who did or where did you get the ported TB from. I have heard that Shanner?? is a good TB. Are you true duals the x pipe style?
Got lots of questions cuz I was just getting ready to go with LS1 stage II heads flowing 305 on the IN and 260 on the EX. I am guessing you already have LS6 heads? Mine are the LS1 in my '00 WS6. Was gonna match it up with a cam with 240-260 dur 112-114 lobe @ 550 lift.

From what I read, he doesn't have ls6 heads, just '01 ls1's.
TRex is from Thunder------>
Most True duals have X junctions, though you'll see a few H junct.'s now and then.

As stated, loose the Harlans and put the stockers back on.

There was some thread that pretty much said that ANY aftermarket aluminum rockers dont have enough weight where it counts,,, over the valve. Which creates float at X RPM with X ammount of lift. I think they were saying if you stay with a .590 and lower lift they were ok,, but what fun is that? :jest: Like everyone is saying, slam the stockers back on, but they are known to explode and send needle bearings everywhere... Sooo, i think it was nasty performance that modifies the stock rockers to handle high lift cams. You get durability, no float, and half the cost of aftermarket rockers. :)

Excellent numbers! I wouldn't worry too much about the power falling off after 6700 unless it's a dramatic decline. I'm of the opinion that a lot of people exaggerate the powerband of large cams. I think you'll find that most T-ReX graphs peak at anywhere from 6400-6700 RPM, then carry near-peak power a bit beyond that.

Josh

Yeah, im very happy with the numbers. Will be putting on a LSX 90/90 combo shortly, and hoping to gain a bit. I still think im having some lifter preload problems, so we have a few things to sort out. I have Comp R lifters in it.. so im thinking of going to a shorter pushrod to compensate. Once thats settled for good, the LSX will go on, and hoping to hit 440 or so.. maybe more, maybe less, dunno. We'll see though :)

And yes, bone stock 2001 heads. Only reason they are 2001, is that i had a stripped spark plug hole, so i swapped out the heads, installed the Comp R's at that time, and ARP head bolts.

Yeah, im very happy with the numbers. Will be putting on a LSX 90/90 combo shortly, and hoping to gain a bit. I still think im having some lifter preload problems, so we have a few things to sort out. I have Comp R lifters in it.. so im thinking of going to a shorter pushrod to compensate. Once thats settled for good, the LSX will go on, and hoping to hit 440 or so.. maybe more, maybe less, dunno. We'll see though :)

And yes, bone stock 2001 heads. Only reason they are 2001, is that i had a stripped spark plug hole, so i swapped out the heads, installed the Comp R's at that time, and ARP head bolts.


Very little preload is required for Comp R lifters.

Rick

Very little preload is required for Comp R lifters.

Rick

4-10 thousandths or so, yes. i beleive they might be overloaded.. but when we did our calculations, it came out to 6 thousandths or so. which should be perfect. dyno graph looked weird above 6700 though, just kinda falls off. may be an air flow problem as well. gunna try a few things and see whats up.. ill try to get the graph scanned and posted soon.

4-10 thousandths or so, yes. i beleive they might be overloaded.. but when we did our calculations, it came out to 6 thousandths or so. which should be perfect. dyno graph looked weird above 6700 though, just kinda falls off. may be an air flow problem as well. gunna try a few things and see whats up.. ill try to get the graph scanned and posted soon.


I would actually just put a quarter turn on the rocker into the lifter to give it 10-25 thou. Thats your best bet. You need some on the lifter, too little and you run into problems.

By the way, how can you calculate preload? All you need is a dial gauge.

Rick

1 7/8's headers

but it seems to die after 6700 or so

I think switching to 1 7/8 is making your car dying after 6700rpm , exactly the same i did after intalling the X3 .

I thought that a 1.7 rockers r not recomanded!!!!

I think switching to 1 7/8 is making your car dying after 6700rpm , exactly the same i did after intalling the X3 .

I thought that a 1.7 rockers r not recomanded!!!!

1.7 = stock

i can tell you what i know from dozens of dyno runs on different cars, you have to have very very strong vavlesprings to make it carry out to where mine does, on jasons car it peaked earlier than mine and didnt carry out as well, after seeing what his did, we used shims to get more seat pressure on the springs and measured them on the spring compressor to get as much as possible without getting coil bind at max lift. mine carried to 6700-6800 and flatlined past 7000 before droping off. i pulled 442 with the lsx manifold going through all my hp robbing drivetrain 12 bolt, steep gears and on 28'' slicks, probably would have gone high 450's and 405rwtq or so with a stock rear and tires. im hoping to get high 450's with the new changes, same drivetrain stock rockers work best and im on stock lifters also. :eek2:

i can tell you what i know from dozens of dyno runs on different cars, you have to have very very strong vavlesprings to make it carry out to where mine does, on jasons car it peaked earlier than mine and didnt carry out as well, after seeing what his did, we used shims to get more seat pressure on the springs and measured them on the spring compressor to get as much as possible without getting coil bind at max lift. mine carried to 6700-6800 and flatlined past 7000 before droping off. i pulled 442 with the lsx manifold and hoping to get high 450's with the new changes. stock rockers work best and im on stock lifters also. :eek2:

im running crane duals, shimmed .060... figured that'd be enough. i have an LSX 90 sitting here, need to get a new lower peice for it, and plug the holes for a previous direct port kit.. then get a NW 90, and ill throw it on and see what i gain.

Ryan,
check your springs, I spoke with a few people that had valve float fom worn out springs on that cam. Check open and seat preasure, spining a nasty lobe like that takes a lot of controle. I spoke with a "competor" shop a year ago or so about the Trex and they recomended a rev kit along with it.
But then again they were also trying to sell me heads saying that I would have 460+rwhp and driveability! :smokin:

Ryan,
check your springs, I spoke with a few people that had valve float fom worn out springs on that cam. Check open and seat preasure, spining a nasty lobe like that takes a lot of controle. I spoke with a "competor" shop a year ago or so about the Trex and they recomended a rev kit along with it.
But then again they were also trying to sell me heads saying that I would have 460+rwhp and driveability! :smokin:

I dont buy the whole rev kit thing. Have you ever seen rev kit springs? You can put them in your hand and compress them. If your lobe is going to float the springs you have now, do you realy think that little helper spring is going to do any better? Its going to take more than a couple more pounds of pressure to help a problem like that.

Rick