Here is the Program
Lexus Fanatic
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Joined: Nov 2004
Posts: 13,441
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From: Under an IS F since 2008
The technician that dyno'd my car the first time thought that 5th gear was 1:1. After the runs I told him that 6th was 1:1, but the baseline had already been run.
My purpose yesterday was to determine if there was significant difference between the hp & tq generated in 5th gear and 6th gear. As you can see, the numbers were almost identical. In a way not surprising since the torque converter is locked up in both gears.
Someone on the Forum had said that because of the gearing that the torque would be higher in a lower gear. That does not appear to be correct from the results of this test. Torque was actually lower in 5th than in 6th, but the difference is so small that I do not believe that it is statistically significant.
Pat
My purpose yesterday was to determine if there was significant difference between the hp & tq generated in 5th gear and 6th gear. As you can see, the numbers were almost identical. In a way not surprising since the torque converter is locked up in both gears.
Someone on the Forum had said that because of the gearing that the torque would be higher in a lower gear. That does not appear to be correct from the results of this test. Torque was actually lower in 5th than in 6th, but the difference is so small that I do not believe that it is statistically significant.
Pat
Hi Pat,
Dyno'ing in 5th & 6th gear also gave us similiar Rwhp results during R&D.
However, the 5th gear Rwtq results were always approx. 9-10 less, due to the fact that 5th gear has a 1:1.231 ratio.
I would say statsically speaking the results in 6th gear will be more accurate in terms of Rwhp & Rwtq.
Also, very glad to see you finally got back to the Dyno.
Your results are right in line with the rest of the group..
20 Rwhp Gained after the Exhaust install.
So far we have members "timetoy" & "houstonT" both dyno'ing in the 375 Rwhp & 379 Rwhp range with the Exhaust & Intake Combo installed..
Congrats,
Joe Z
Lead Lap
Joined: Jan 2004
Posts: 520
Likes: 3
From: Texas
I am very curious as to what the intake tube will give you Pat. I made 383 rwhp at no smoothing and 379.39 rwhp at smoothing set to 5. I would expect with the tune, exhaust and intake you'd be over 400 rwhp SAE.
Peter
Peter
Thread Starter
Pole Position
Joined: Aug 2008
Posts: 218
Likes: 1
From: Houston, Texas
Peter,
I had Jay weld on a "bung" so that I could get accurate A/F ratios. He welded it on just in front of the O2 sensor on the passenger's side. When Andy gets back in country they are going to reprogram the ECM to take advantage of all the changes we have made thus far. Should be getting close to the 400 rwhp mark fairly soon.
After looking at the exhaust manifolds on these engines, I believe that a set of long tube headers should add 20-25 hp. They appear to be very restrictive to me. After we get long tube headers we should give new M3's hexx.
The interesting thing to me is how much improvement we have gotten in rwtq. Still peaking out at 5,200 - 5,400 rpm. Drops to right at 300 rwtq at 6,500 rpm.
This engine is still very sensitive to temperature. Ran it hot and got about 365 rwhp. Put it on the fan for about 30 minutes and rwhp jumped to 377.
Andy is sending me a new 180 deg thermostat. That should help.
Pat
I had Jay weld on a "bung" so that I could get accurate A/F ratios. He welded it on just in front of the O2 sensor on the passenger's side. When Andy gets back in country they are going to reprogram the ECM to take advantage of all the changes we have made thus far. Should be getting close to the 400 rwhp mark fairly soon.
After looking at the exhaust manifolds on these engines, I believe that a set of long tube headers should add 20-25 hp. They appear to be very restrictive to me. After we get long tube headers we should give new M3's hexx.
The interesting thing to me is how much improvement we have gotten in rwtq. Still peaking out at 5,200 - 5,400 rpm. Drops to right at 300 rwtq at 6,500 rpm.
This engine is still very sensitive to temperature. Ran it hot and got about 365 rwhp. Put it on the fan for about 30 minutes and rwhp jumped to 377.
Andy is sending me a new 180 deg thermostat. That should help.
Pat
Lou
Lexus Fanatic
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Posts: 13,441
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From: Under an IS F since 2008
Lou, this is the best I could do on short notice... 
I would say the manifolds are very "flat" in design...
Plus, its a super tight engine bay...
A few Internal Pics of IS-F Engine Parts
and a link the Lexus website below
http://www.lexus.com/models/ISF/feat...gine_Story.pdf
Joe Z
I would say the manifolds are very "flat" in design...
Plus, its a super tight engine bay...
A few Internal Pics of IS-F Engine Parts
and a link the Lexus website below
http://www.lexus.com/models/ISF/feat...gine_Story.pdf
Joe Z
Thanks Joe
I've seen the drawings and engine story. I know it was a very tight engine compartment. When I look up from underneath or down from above I can see that. I also knew (thought) the exhaust manifold had to be designed to fit, rather than for performance. I would like to see a pict of it, if anyone has it. Does anyone think that a set of tube headers can be made to fit the confines imposed by stuffing this engine in the IS?
Lou
I've seen the drawings and engine story. I know it was a very tight engine compartment. When I look up from underneath or down from above I can see that. I also knew (thought) the exhaust manifold had to be designed to fit, rather than for performance. I would like to see a pict of it, if anyone has it. Does anyone think that a set of tube headers can be made to fit the confines imposed by stuffing this engine in the IS?
Lou
Driver
Joined: Dec 2008
Posts: 61
Likes: 0
From: St Petersburg, FL
yup-log style exhaust manifolds. perfect for tight spaces. Should be fun for whoever decides to tackle building headers for our cars.
The engine pics are cool. That intake looks like a perfect candidate for extrude honing.
The engine pics are cool. That intake looks like a perfect candidate for extrude honing.
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Thread Starter
Pole Position
Joined: Aug 2008
Posts: 218
Likes: 1
From: Houston, Texas
The long tube headers will probably be 1 5/8 inch diameter primarys. The headers will probably have to make a quick 90 deg turn down after exiting the head and then run parallel (one above the other until they get to the collector. The primary cats will have to be have to move toward the rear of the car. Just my opinion.
Pat
Pat
How? The stock thermostat is integral to an assembly, and the stock temperature is 180F. Sometimes there's value in learning about what already exists before recommending a solution. Note the repair procedure stating you must replace the entire sub-assembly. See below:
FWIW, reducing parts count is a very effective way of reducing spares costs for the manufacturer and increasing the spares costs for the end owner. I don't like it, but it's the direction they've decided they need to go to continue to push prices down against their competition.
Last edited by lobuxracer; Mar 16, 2009 at 03:46 PM.
Thread Starter
Pole Position
Joined: Aug 2008
Posts: 218
Likes: 1
From: Houston, Texas
I guess it reduces their direct assembly cost since there are fewer parts to assemble, but someone (the parts supplier) has to make the assembly.
Like you, as an end user who might keep this vehicle for 8-10 years I do not like the idea of having to buy a complete hub just because a wheel bearing needs replacing.
Pat
Like you, as an end user who might keep this vehicle for 8-10 years I do not like the idea of having to buy a complete hub just because a wheel bearing needs replacing.
Pat