Could it be in the tune?
11-14-2016, 03:04 PM
#22
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So I've ran the car at five or more auto cross events. I have added a larger rear brake set up and 275 Hoosiers on 15x10's. The car feels great and have even set FTD at a couple.
But now I'm getting to where I know I need more power and a higher redline. So I decided to revive an old thread and get some input from you guys.
I was thinking of swapping the head to VVT and purchasing a better oil pump, crank dampener, and higher compression pistons to go along with it. Since I want to rev it to the neighborhood of 8-9k, I'm wanting to be on the safe side and also have the head built. 949racing sells a cnc'd head that I believe will be reliable.
You can see what's done to the car in this thread. I'd love to hear some feedback because I'm sure I'm forgetting something or maybe there is a better way.
But now I'm getting to where I know I need more power and a higher redline. So I decided to revive an old thread and get some input from you guys.
I was thinking of swapping the head to VVT and purchasing a better oil pump, crank dampener, and higher compression pistons to go along with it. Since I want to rev it to the neighborhood of 8-9k, I'm wanting to be on the safe side and also have the head built. 949racing sells a cnc'd head that I believe will be reliable.
You can see what's done to the car in this thread. I'd love to hear some feedback because I'm sure I'm forgetting something or maybe there is a better way.
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11-15-2016, 01:01 PM
#24
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^This.
But the idea of a 949 head is a good one.
140whp is good for the early 1.8. They were rated at 133 crank hp fro the factory and often make 120 or less at the wheels.
But the idea of a 949 head is a good one.
140whp is good for the early 1.8. They were rated at 133 crank hp fro the factory and often make 120 or less at the wheels.
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11-15-2016, 02:38 PM
#25
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What is the early 1.8 with a 949 VVT head capable of in my case? 7800 limit with @170whp?
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11-15-2016, 04:18 PM
#26
I agree that the crank is a weak point, although I can't recall the rpm range it will go to while balanced to the rest of the rotating assembly. A billet crank would be the way to go, although I want to keep it safe within the limits of the stock shaft and see how that goes before throwing a wad of cash at one.
What is the early 1.8 with a 949 VVT head capable of in my case? 7800 limit with @170whp?
What is the early 1.8 with a 949 VVT head capable of in my case? 7800 limit with @170whp?
EDIT: Baseline for my car was 105 whp. Hoping for 150 with head, full exhaust, intake, and MS3.
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11-17-2016, 11:19 PM
#29
Just saw this pic. That intake is awful. Steel is a no go. Needs to be aluminum to get rid of heat when you open throttle. Steel has much higher thermal mass and lower thermal inertia. It gets hot and stays hot.
Mandrel bends are key, particularly near the TB where you need to retain velocity. Yours also changes cross sectional shape and area. Both are bad. You set up resonance waves in there with those changes. Keep the ID constant from the TB to the filter. Increase the radius of that first bend at the TB as much as you can. That intake is costing you 5whp when the hood is closed.
MX-5 Miata Forum - View Single Post - 180whp 152tq CNC head
Mandrel bends are key, particularly near the TB where you need to retain velocity. Yours also changes cross sectional shape and area. Both are bad. You set up resonance waves in there with those changes. Keep the ID constant from the TB to the filter. Increase the radius of that first bend at the TB as much as you can. That intake is costing you 5whp when the hood is closed.
MX-5 Miata Forum - View Single Post - 180whp 152tq CNC head
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11-18-2016, 06:10 AM
#31
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Just saw this pic. That intake is awful. Steel is a no go. Needs to be aluminum to get rid of heat when you open throttle. Steel has much higher thermal mass and lower thermal inertia. It gets hot and stays hot.
Mandrel bends are key, particularly near the TB where you need to retain velocity. Yours also changes cross sectional shape and area. Both are bad. You set up resonance waves in there with those changes. Keep the ID constant from the TB to the filter. Increase the radius of that first bend at the TB as much as you can. That intake is costing you 5whp when the hood is closed.
MX-5 Miata Forum - View Single Post - 180whp 152tq CNC head
Mandrel bends are key, particularly near the TB where you need to retain velocity. Yours also changes cross sectional shape and area. Both are bad. You set up resonance waves in there with those changes. Keep the ID constant from the TB to the filter. Increase the radius of that first bend at the TB as much as you can. That intake is costing you 5whp when the hood is closed.
MX-5 Miata Forum - View Single Post - 180whp 152tq CNC head
LOL
I know right, but he's got a point. I never would have saw that and none of the folks posting here did either. Glad to have him around.
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