twins and intake dyno today....
10-08-2006, 11:00 PM
#1
twins and intake dyno today....
i am a little disapointed. not really sure what is going on. either i have some issue i am not aware of or the intake didn't do much and even hurt power for most of the run. in my mind the intake design on a boosted set up should be as open and strait to the head as you can be, it seems like runner length shouldn't matter when you are pushing the air into the cylinder but from my charts it looks as if i lost a fair amont of low end in favor of a slight amount of top end. if i had a solid valve train then i think i could take the rpms up to 7000rpm and see some nice gains up top but with a hydrolic set up the high rpms are not there. valve float kicks in about 6500 and even sooner with the high boost. the chart below is about 13psi, both runs are with the twins and closed exhaust. run1 is the stock intake and run 13 is the eldebrock intake. there is one thing i didn't think about at the dyno. the stock intake was with pump gas and the new intake was with race fuel and i never tried adjusting the timing. from what i have been told race fuel needs a little more timing due to the slower burn rate? that probably would have made up some of the diference.
the high boost hp numbers are interesting. there is some good news and probably some et gains to be had with the twins/intake. this next set of graphs compares the single with stock intake(run 16) to the twins with the eldebrock intake(run 24). both runs are with open exhaust and race fuel.
while turning it up we tried adding some timing and it perked up prety good going from 13 to 16deg. we didn't try any more timing than that. we probably should have just to see what it did. during a run down the track most of my time is spent above 5400rpm so you can see where i should pick up some et at this boost level. the twins seems to really hold the boost well and react well to the boost controler adjustments. we turned it up one run higher than the one posted below, more like 25psi and it had a peek of 1021hp but the hp was lower in the higher rpms. i believe it is hiting valve float at that boost level.
with the hydrolic cam i think i will keep the boost down around 22-23psi max and if i dont hit my goal at that boost level then add a little more timing and see if it picks up any et. i nearly hit my goal of 9.99 with the single and there is close to an extra 100hp up in the rpms where i will be for most of the run so i see a 9.xx as a real posiablity. i think for the twins and intake to really shine i would need a solid roller and run this thing up to 7000rpm along with some even higher boost. without the solid roller i think i would be better off with some smaller turbos.
something to mention. for some reason with the twins and intake it runs and drives better than it ever has. at the track the big single would actualy build tq too fast down low. not instant, it still needed some nitrous but once it started to build boost i couldn't turn it low enough to avoid wheel spin. now with the twins it seems to bring the power on at a rate that works well. i made 6 runs over 1000rwhp.
last trip to the track i was running out of fuel. since then i plumbed my fuel rails in parallel and hooked up a boost a pump running my pumps at 17volts. on the dyno it held fuel presure so i am ready to try the track again. maybe next saturday if i can find a track with an open test and tune. damn 9's are kicking my ***!
the high boost hp numbers are interesting. there is some good news and probably some et gains to be had with the twins/intake. this next set of graphs compares the single with stock intake(run 16) to the twins with the eldebrock intake(run 24). both runs are with open exhaust and race fuel.
while turning it up we tried adding some timing and it perked up prety good going from 13 to 16deg. we didn't try any more timing than that. we probably should have just to see what it did. during a run down the track most of my time is spent above 5400rpm so you can see where i should pick up some et at this boost level. the twins seems to really hold the boost well and react well to the boost controler adjustments. we turned it up one run higher than the one posted below, more like 25psi and it had a peek of 1021hp but the hp was lower in the higher rpms. i believe it is hiting valve float at that boost level.
with the hydrolic cam i think i will keep the boost down around 22-23psi max and if i dont hit my goal at that boost level then add a little more timing and see if it picks up any et. i nearly hit my goal of 9.99 with the single and there is close to an extra 100hp up in the rpms where i will be for most of the run so i see a 9.xx as a real posiablity. i think for the twins and intake to really shine i would need a solid roller and run this thing up to 7000rpm along with some even higher boost. without the solid roller i think i would be better off with some smaller turbos.
something to mention. for some reason with the twins and intake it runs and drives better than it ever has. at the track the big single would actualy build tq too fast down low. not instant, it still needed some nitrous but once it started to build boost i couldn't turn it low enough to avoid wheel spin. now with the twins it seems to bring the power on at a rate that works well. i made 6 runs over 1000rwhp.
last trip to the track i was running out of fuel. since then i plumbed my fuel rails in parallel and hooked up a boost a pump running my pumps at 17volts. on the dyno it held fuel presure so i am ready to try the track again. maybe next saturday if i can find a track with an open test and tune. damn 9's are kicking my ***!
10-08-2006, 11:11 PM
#2
might try these:
https://ls1tech.com/forums/showthrea...6&page=1&pp=20
excellent results
post up the data on the DTL and I'll update it for the top spot
https://ls1tech.com/forums/showthrea...6&page=1&pp=20
excellent results
post up the data on the DTL and I'll update it for the top spot
10-08-2006, 11:26 PM
#3
Originally Posted by moregrip
might try these:
https://ls1tech.com/forums/showthrea...6&page=1&pp=20
excellent results
post up the data on the DTL and I'll update it for the top spot
https://ls1tech.com/forums/showthrea...6&page=1&pp=20
excellent results
post up the data on the DTL and I'll update it for the top spot
Parish, what springs are you running?
These should be about the limit for a hydraulic cam since over 350 open pressure is a recipe for lifter failure.
I have seen many people push high 6K rpms with high teens low twenties in boost with no valve float over on tech with the PRC dual gold setups. You might also check into titanium retainers to lighten up your valvetrain a bit if you dont already have them.
You are putting alot of pressure on those valves with that much boost
10-08-2006, 11:37 PM
#4
Not knocking the set-up at all Jim, in fact planned on running that manifold, but do you think that 90* elbow is holding back a bit of power?
I beleive on tech someone had lost 50rwhp on a corvette with a turbo set-up using an almost identical elbow.
If it is there really is no other way though for your turbo set-up. Impressive numbers none the less!
I beleive on tech someone had lost 50rwhp on a corvette with a turbo set-up using an almost identical elbow.
If it is there really is no other way though for your turbo set-up. Impressive numbers none the less!
10-08-2006, 11:42 PM
#6
i have the comp 921's not sure of the specs. i believe i am seeing significant valve float at 25psi and 6200rpm. not exactly sure when or if it hits at lower boost levels.
isnt there more to high a high rpm valve train than avoiding float? dont the lifters start to compress some and you actualy loose some lift? i think that wheel to wheel nova spins to 7000+rpm with a solid roller and a fair amont of boost and it seems like harlen took his car to 7000+rpm with a solid roller. my cam might be a tad on the small side if i am thinking about pushing it to 7000rpm but i really dont know. i dont want to kill anymore low end, it seems about right now.
with the parts i have in the bottom end it should be ok at 7000rpm. if the valves didn't float i could keep upping the boost with the turbos that i have. maybe at much as 35psi. the hp was going up nicely with every boost increase untill it droped off sharply when we hit 25psi and float.
isnt there more to high a high rpm valve train than avoiding float? dont the lifters start to compress some and you actualy loose some lift? i think that wheel to wheel nova spins to 7000+rpm with a solid roller and a fair amont of boost and it seems like harlen took his car to 7000+rpm with a solid roller. my cam might be a tad on the small side if i am thinking about pushing it to 7000rpm but i really dont know. i dont want to kill anymore low end, it seems about right now.
with the parts i have in the bottom end it should be ok at 7000rpm. if the valves didn't float i could keep upping the boost with the turbos that i have. maybe at much as 35psi. the hp was going up nicely with every boost increase untill it droped off sharply when we hit 25psi and float.
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10-08-2006, 11:48 PM
#9
Originally Posted by Z06 DREAMING
Not knocking the set-up at all Jim, in fact planned on running that manifold, but do you think that 90* elbow is holding back a bit of power?
I beleive on tech someone had lost 50rwhp on a corvette with a turbo set-up using an almost identical elbow.
If it is there really is no other way though for your turbo set-up. Impressive numbers none the less!
I beleive on tech someone had lost 50rwhp on a corvette with a turbo set-up using an almost identical elbow.
If it is there really is no other way though for your turbo set-up. Impressive numbers none the less!
