Lexus ISF AEM FIC? Exhaust? TB? More hp
10-08-18, 05:18 PM
#1
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Thread Starter
Lexus ISF AEM FIC? Exhaust? TB? More hp
Anyone tried or thought of using one of these to actually dyno tune the car? I know this car has more potential in it then 420whp NA. Another thing anyone actually try a bigger exhaust as well? I feel the tiny 2.5 dual isn’t enough when I see 4 cylinder Honda’s benefit from a 3” exhaust. Since we have 8 cylinders I’m sure each head would also benefit from a 3” off each header. Another thing 392 hemi comes with 80mm tb and 2.75 true dual exhaust stock. (yes I know different cars but similar power) but if they come stock with such a big TB and exhaust why wouldn’t we benefit from it?
I truly feel this car has more in it and this link I provided is for all the people who say it’s impossible. https://www.nissanclub.com/forums/20.../topics/497625
On the Nissan forum EVERYONE told me and by everyone I mean tuners, “experts”, shops, etc tell me there is no way that car can make 300whp and guess what I proved everyone wrong. A couple of things I think this car can benefit from:
4” intake
PPE headers
80mm bores out TB and port matched IM
2.75” or 3” TD exhaust
maybe use AEM FIC to dyno tune car with those mods
I truly feel this car has more in it and this link I provided is for all the people who say it’s impossible. https://www.nissanclub.com/forums/20.../topics/497625
On the Nissan forum EVERYONE told me and by everyone I mean tuners, “experts”, shops, etc tell me there is no way that car can make 300whp and guess what I proved everyone wrong. A couple of things I think this car can benefit from:
4” intake
PPE headers
80mm bores out TB and port matched IM
2.75” or 3” TD exhaust
maybe use AEM FIC to dyno tune car with those mods
Last edited by ISFpowered; 10-08-18 at 05:21 PM.
10-08-18, 07:07 PM
#3
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You might want to review RRRacing's development. They've already tried and proved or disproved a number of things. Might save some trial and error.
10-08-18, 07:23 PM
#4
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Thread Starter
Funny thing when you mention them. Rafi said it’s nonsense. Idk how someone can say nonsense when it hasn’t been tried. I see they tried the RCF 85mm TB but with that 3.5” intake pipe how would that benefit. If 200hp Honda’s and my old V6 Nissan benefitted from a 4” intake how could a 400+ Lexus not? I’ve tried mentioning some ideas here and there but they just shrug it off. If you click on the link you’ll see how many people doubted a VQ35DE could even come close to 300whp without using nitrous or FI. It’s crazy how closed minded some people could be and not want to break barriers and take things to the next level. I had all kinds of people tell me it’s impossible. Reminds me of the Acura TL days when people were trying to break 300whp and started putting 3” exhausts which were said to only be needed on boosted cars and people putting 4” intakes on it and gaining everywhere and losing nothing.
Last edited by ISFpowered; 10-08-18 at 07:33 PM.
10-08-18, 07:28 PM
#5
Instructor
Thread Starter
Another thing they said they tried was a bigger exhaust but I didn’t see a dyno sheet or any proof. Plus why bother getting a bigger exhaust when your bottle neck is at the intake pipe or TB. You need all the parts to work together. Just having one of the other won’t be enough or cause loses. I had the same band wagon mentality back in the day like 2.5 exhaust was all you needed for all motor and 3” intake was all you need any bigger and you lose power and torque which some people still have till this day. On both Honda and Acura forums people put 3” exhaust on a bone stock 4 and 6 cylinder and show gains everywhere in the RPM with no loses same with the 4” intake. I just refuse to believe 420 is all this motor has in it. I would be happy if I found another 10-20hp from the car that no one has tried or thought of.
Last edited by ISFpowered; 10-08-18 at 07:35 PM.
10-08-18, 07:38 PM
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10-08-18, 08:06 PM
#8
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A few things:
1) tried ISF ported intake manifold with 84mm RCF TB and 87mm MAF.... the larger TB did not help.
2) tried long tube headers with dual 3” pipes... even with the Supercharger, the ISF did not make more power.
3) American Racing headers makes a 1 7/8 long tube header with dual 3” exhaust combo for the RCF. We tested this with the Supercharger.... and it DOES NOT make any more power than PPE and Dual 2.5” exhaust combo, with or without the Supercharger.
Part of the reason may be that the exhaust ports on the ISF/RCF are only 1.5”.
So bottom line is, we have extensively tested all these things. We would have loved to say any of these things work, as we’d have more upgrades to sell... but they don’t work, so we stick to what we found is effective.
As for why some 4cyl Honda’s benefit from larger exhausts... most Honda heads, partly because of VTEC and very high flow design (i.e. k20s) have very high flow per cylinder. F20s make 120hp per liter! If the ISF had that kind of flow per cylinder, we’d be making 600hp NA
Rafi
1) tried ISF ported intake manifold with 84mm RCF TB and 87mm MAF.... the larger TB did not help.
2) tried long tube headers with dual 3” pipes... even with the Supercharger, the ISF did not make more power.
3) American Racing headers makes a 1 7/8 long tube header with dual 3” exhaust combo for the RCF. We tested this with the Supercharger.... and it DOES NOT make any more power than PPE and Dual 2.5” exhaust combo, with or without the Supercharger.
Part of the reason may be that the exhaust ports on the ISF/RCF are only 1.5”.
So bottom line is, we have extensively tested all these things. We would have loved to say any of these things work, as we’d have more upgrades to sell... but they don’t work, so we stick to what we found is effective.
As for why some 4cyl Honda’s benefit from larger exhausts... most Honda heads, partly because of VTEC and very high flow design (i.e. k20s) have very high flow per cylinder. F20s make 120hp per liter! If the ISF had that kind of flow per cylinder, we’d be making 600hp NA
Rafi
Last edited by RRRacing; 10-08-18 at 08:17 PM.
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10-08-18, 08:15 PM
#9
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Thread Starter
A few things:
1) tried ISF ported intake manifold with 84mm RCF TB and 87mm MAF.... the larger TB did not help.
2) tried long tube headers with dual 3” pipes... even with the Supercharger, the ISF did not make more power.
3) American Racing headers makes a 1 7/8 long tube header with dual 3” exhaust combo for the RCF. We tested this with the Supercharger.... and it DOES NOT make any more power than PPE and Dual 2.5” exhaust combo, with or without the Supercharger.
Part of the reason may be that the exhaust ports on the ISF/RCF are only 1.5”.
So bottom line is, we have extensively tested all these things. We would have loved to say any of these things work, as we’d have more upgrades to sell... but they don’t work, so we stick to what we found is effective.
Rafi
1) tried ISF ported intake manifold with 84mm RCF TB and 87mm MAF.... the larger TB did not help.
2) tried long tube headers with dual 3” pipes... even with the Supercharger, the ISF did not make more power.
3) American Racing headers makes a 1 7/8 long tube header with dual 3” exhaust combo for the RCF. We tested this with the Supercharger.... and it DOES NOT make any more power than PPE and Dual 2.5” exhaust combo, with or without the Supercharger.
Part of the reason may be that the exhaust ports on the ISF/RCF are only 1.5”.
So bottom line is, we have extensively tested all these things. We would have loved to say any of these things work, as we’d have more upgrades to sell... but they don’t work, so we stick to what we found is effective.
Rafi
10-08-18, 08:25 PM
#10
Instructor
Thread Starter
As for why some 4cyl Honda’s benefit from larger exhausts... most Honda heads, partly because of VTEC and very high flow design (i.e. k20s) have very high flow per cylinder. F20s make 120hp per liter! If the ISF had that kind of flow per cylinder, we’d be making 600hp NA
Rafi
Rafi
10-08-18, 08:37 PM
#11
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The only way to make bigger power gains on NA ISF is head porting and cams. The cost of these mods are high, so there isn’t much of a market in doing it. An RCF engine is basically a modded ISF engine. They made 50hp by (1) increasing compression (2) about 800psi higher DI fuel pressure (3) larger valves, (4) revised camshafts, (5) ported intake manifold and larger TB, and slightly better exhaust system.
Rafi
10-08-18, 08:40 PM
#12
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Thread Starter
you cant use the fic to tune the ISF... it’s been tried many times over the past 10 years. We use the FIC only for some fueling mods on the port injectors, and only in tandem with ECU recalibration that makes it work.
The only way to make bigger power gains on NA ISF is head porting and cams. The cost of these mods are high, so there isn’t much of a market in doing it. An RCF engine is basically a modded ISF engine. They made 50hp by (1) increasing compression (2) about 800psi higher DI fuel pressure (3) larger valves, (4) revised camshafts, (5) ported intake manifold and larger TB, and slightly better exhaust system.
Rafi
Would still like to know about this.
“87mm intake so 3.5 inch piping. Did you try a 4 inch intake? Did you try it alone or without a TB? How about trying a 4” over the 3.5” and seeing what happens and then trying it with a 80mm or 84mm TB. With the dual 3” setup did you just put it on and dyno it or try and tune with it on? The 1.5 exhaust ports is definitely a killer. I just hate seeing the 5.0 mustangs doing 450whp with minor mods.”
Last edited by ISFpowered; 10-08-18 at 10:03 PM.
10-09-18, 03:45 AM
#13
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Nobody makes cams for our cars though. Would a RCF cam drop right in for us? Or better yet would RCF heads bolt up to our block?
Would still like to know about this.
“87mm intake so 3.5 inch piping. Did you try a 4 inch intake? Did you try it alone or without a TB? How about trying a 4” over the 3.5” and seeing what happens and then trying it with a 80mm or 84mm TB. With the dual 3” setup did you just put it on and dyno it or try and tune with it on? The 1.5 exhaust ports is definitely a killer. I just hate seeing the 5.0 mustangs doing 450whp with minor mods.”
Rafi
10-09-18, 12:12 PM
#14
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Anybody have a scrap head laying around? I'd like to take a look at the ports for some measurements. A 35mm port isn't bad if it's done right, but if they did it like the 2JZ-GTE, there's a lot of room for improvement.
And yes, I know port work is expensive for other people so it doesn't fit into an upgrade path for most. I also know what I charge for it.
And yes, I know port work is expensive for other people so it doesn't fit into an upgrade path for most. I also know what I charge for it.
10-09-18, 12:47 PM
#15
Anybody have a scrap head laying around? I'd like to take a look at the ports for some measurements. A 35mm port isn't bad if it's done right, but if they did it like the 2JZ-GTE, there's a lot of room for improvement.
And yes, I know port work is expensive for other people so it doesn't fit into an upgrade path for most. I also know what I charge for it.
And yes, I know port work is expensive for other people so it doesn't fit into an upgrade path for most. I also know what I charge for it.
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