intake restriction on stroker cts-v
10-23-2014, 06:34 PM
#1
intake restriction on stroker cts-v This is my dyno graph
I'm trying to figure out if i have an intake restriction that's causing the power to flatten out instead of continuing to climb. I'm using the Volant cai and others have said its not the greatest, buts its the only thing that easily fits in my cramped car. I logged a pull at wot and the map kpa is 96 from 2000-4000 rpm, then from 4700-6000 its at 93-94kpa going back and fourth, then from 6000-6500 its going from 91-92kpa. With my setup I was expecting to make in the high 530s-low 540s so i was thinking it may be the intake? What does everyone think?
I'm trying to figure out if i have an intake restriction that's causing the power to flatten out instead of continuing to climb. I'm using the Volant cai and others have said its not the greatest, buts its the only thing that easily fits in my cramped car. I logged a pull at wot and the map kpa is 96 from 2000-4000 rpm, then from 4700-6000 its at 93-94kpa going back and fourth, then from 6000-6500 its going from 91-92kpa. With my setup I was expecting to make in the high 530s-low 540s so i was thinking it may be the intake? What does everyone think?
10-23-2014, 08:40 PM
#3
Looks like it to me. What does the MAP read with key-on engine-off? If it's 100kpa, then I wouldn't like anything less than 95 at WOT. I used to have a 3.5" intake tube, a smaller filter and a 85mm MAF. I removed all of that and installed a 4" tube, a much larger filter and deleted the MAF to run in SD. My KPA at WOT went from 92-93 at peak to 95-96 and was about 2 kpa higher everywhere else. Remember that engine vacuum is the difference between the pressures in the intake manifold (MAP) and ambient atmospheric pressure. If ambient is 100 KPA and you're seeing 91 KPA, you've got a 9 KPA difference and are seeing a meaningful amount of vacuum. There's more power to be had there for sure!
10-23-2014, 09:02 PM
#4
I don't have hp tuners ( Just the demo), i'm just looking at the log of the pull my tuner sent me. From 2000-3000 its going from 99-96kpa back and fourth at wot. Now i guess i just need to find out where the restriction is. My Tuner says the only way to really find out is to hook it to the dyno and use sensors to check the manifold and the intake tube and box. But from what i've heard from many others it seems to be my tube. Hooking up to the dyno and tuning and checking for restrictions will cost about $400 so i'd love it if i could just throw on a tube for 50 and fix it lol. My air fuel is 11.8-12 at wot the whole pull so even if it leans out a bit with the better tube it should be fine. Just really want to avoid spending that $400 lol. Thanks for the reply 1970camaroRS 
10-23-2014, 10:01 PM
#6
its tuned with a wide band on dyno for afr. My tuner is super conservative with afr. He basically has zero trust in pump gas with all the varying degrees of ethanol. Its got plenty of timing though. It ramps from 30 at 3250 to 32.5 at 6800. no knock even in 95 degree days
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10-23-2014, 10:11 PM
#8
Yeh it just sucks that the volant is the best thing you can do without going custom. The volant box is great but the tube is definite garbage. Its just so tight in between the radiator and accessory belts that almost nothing else fits. If i put a 4" tube in i'd have almost 0 space between it and the belt. Too close for comfort anyway. I've played with the idea of getting an air raid DIY 4" 90 and either 4" or 3.5" tube and mating it to the volant box, but there is a radiator bolt that obstructs the path to the maf attached to the box. The volant tube is deformed to fit it (Which is also probably part of the prob).
10-24-2014, 02:14 PM
#9
its tuned with a wide band on dyno for afr. My tuner is super conservative with afr. He basically has zero trust in pump gas with all the varying degrees of ethanol. Its got plenty of timing though. It ramps from 30 at 3250 to 32.5 at 6800. no knock even in 95 degree days
Yeh it just sucks that the volant is the best thing you can do without going custom. The volant box is great but the tube is definite garbage. Its just so tight in between the radiator and accessory belts that almost nothing else fits. If i put a 4" tube in i'd have almost 0 space between it and the belt. Too close for comfort anyway. I've played with the idea of getting an air raid DIY 4" 90 and either 4" or 3.5" tube and mating it to the volant box, but there is a radiator bolt that obstructs the path to the maf attached to the box. The volant tube is deformed to fit it (Which is also probably part of the prob).
Granted, I don't have the engine compartment constraints like you, but here's my setup on my g-body.
Attachment 724397
10-24-2014, 02:39 PM
#10
That AFR is rich even if tuning for E10. .85 to .9 lambda on e10 is about 12 to 12.7 AFR, but that's not solid works for every combo. Also, I'm far from an expert. And then that timing is really high, but not insane. I'm a little surprised by it though, but if it's been on the dyno and that's where it makes power...that must be ok.
You're at the point where you're going to have to start cutting and moving things around. Move the radiator forward...come up with a different route for your CAI...flip bolt head directions around...cut new holes in the radiator support...move your accessories around...etc. Otherwise, you'll just have to live with a slightly choked intake.
Granted, I don't have the engine compartment constraints like you, but here's my setup on my g-body.
You're at the point where you're going to have to start cutting and moving things around. Move the radiator forward...come up with a different route for your CAI...flip bolt head directions around...cut new holes in the radiator support...move your accessories around...etc. Otherwise, you'll just have to live with a slightly choked intake.
Granted, I don't have the engine compartment constraints like you, but here's my setup on my g-body.