Dyno results of GT with x pipe
10-11-2005, 07:02 PM
#18
Drifting
So Mark, you got almost 24 peak hp with no cats? Not too bad. All my testing was done without a RRFPR. You are correct that there is more to be had with it but we are trying to show the gains from the X alone. There's more to be gained from increased displacement, and compression, and lift, and duration, and, and, and.
10-11-2005, 07:09 PM
#19
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Just to confirm what John said, I got 4 more HP with the top off the air cleaner, hood open, and stock air filter in place. I can't imagine that a rising rate fuel pressure regulator would be useful until I can get some more air flow.
I'm wondering what a timing advance would do. Seems to me that the AF curve is fairly fixed by the ECU and, like the dyno guy said, "The car is in diapers from the factory".
In my VERY humble opinion, with further exhaust and intake modifications, the engine SHOULD be able to produce 350HP normally aspirated at the rear wheels.
I'm wondering what a timing advance would do. Seems to me that the AF curve is fairly fixed by the ECU and, like the dyno guy said, "The car is in diapers from the factory".
In my VERY humble opinion, with further exhaust and intake modifications, the engine SHOULD be able to produce 350HP normally aspirated at the rear wheels.
10-11-2005, 07:13 PM
#20
Well considering that Louie Ott got his GT to 325 NA.....I would like to see the 350rwhp numbers...go for it..and document well. so that others may/will follow... 
Later,
Tom
89GT
Later,
Tom
89GT
10-11-2005, 07:33 PM
#21
Rennlist Member
Originally Posted by Ketchmi
Higher altitude actually makes cars run richer not leaner. If you hook up a DVM to the O2 sensor output you can make a cheap and easy A/F meter. I built a jig that goes inline for testing that works great but I use it enough I can't send it to Canada. Just tapping into the black wire on the O2 sensor you should be able to read the voltage. If it's at .75 to .85 VDC you are OK. That is at WOT and higher rpm (4k plus) when the car reverts to the proprogrammed map and is no longer operating in closed loop.
Almost any exhaust improvements you do to your car will cause the engine to run leaner as you have increased it's airflow efficiency without adding more fuel. Normally with just an X-over you are still OK and within factory variables. When I added our cat back system to one of our dyno mules it went way too lean and whereas the cat back gained 11hp and 15#'s of torque on the stock cats, it only gained 4hp with the X-over. Getting more fuel to it would have given me much better numbers but that wasn't the purpose of that exercise.
Almost any exhaust improvements you do to your car will cause the engine to run leaner as you have increased it's airflow efficiency without adding more fuel. Normally with just an X-over you are still OK and within factory variables. When I added our cat back system to one of our dyno mules it went way too lean and whereas the cat back gained 11hp and 15#'s of torque on the stock cats, it only gained 4hp with the X-over. Getting more fuel to it would have given me much better numbers but that wasn't the purpose of that exercise.
Rather than having the SO hand hold the DVM @ +4k rpm in third its probably easier to visit SLC for a RRFR and a dyno run. Any predictions on snow anytime soon?
10-11-2005, 07:52 PM
#22
Drifting
Already have some in the mountains, may have to hold off until spring.
You may certainly be correct about running lean, I don't doubt that. My 86.5' would lean out in third gear (auto) at about 130ish mph WITH a RRFPR. I needed to do some more work on it so I just wrecked it instead. Put the problem off for another day (year).
You may certainly be correct about running lean, I don't doubt that. My 86.5' would lean out in third gear (auto) at about 130ish mph WITH a RRFPR. I needed to do some more work on it so I just wrecked it instead. Put the problem off for another day (year).
10-11-2005, 08:05 PM
#23
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Ph, was that the test without cats .... 
We did this test a few times ...and the results always seem to be the same. Our cats are 300 cell metal foil cats ... expensive, but the flow is very high.
I do not plan to use the RR for awhile, until we have a good enough data pool to average the results over.
Again, not the highest readings.
Marc
We did this test a few times ...and the results always seem to be the same. Our cats are 300 cell metal foil cats ... expensive, but the flow is very high.
I do not plan to use the RR for awhile, until we have a good enough data pool to average the results over.
Again, not the highest readings.
Marc
10-11-2005, 08:53 PM
#26
Rennlist Member
Originally Posted by Ketchmi
Already have some in the mountains, may have to hold off until spring.
You may certainly be correct about running lean, I don't doubt that. My 86.5' would lean out in third gear (auto) at about 130ish mph WITH a RRFPR. I needed to do some more work on it so I just wrecked it instead. Put the problem off for another day (year).
You may certainly be correct about running lean, I don't doubt that. My 86.5' would lean out in third gear (auto) at about 130ish mph WITH a RRFPR. I needed to do some more work on it so I just wrecked it instead. Put the problem off for another day (year).
If time and weather permits I may also go back to the stock LH eprom.............sidebar discussion w/John Speake.
10-11-2005, 09:53 PM
#27
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I was able to post 333 rwhp with my 89 gt with an otto x pipe 2.5 duel exhaust with borlas, a modified airbox ( another otto mod) mass air screens removed, larger air intake tubes,and msds long tube headers. I dont know what else I left on the table.I think that 350 rwhp would be hard to achive with just bolt ons except one SUPERCHARGING ! Then 500 is no problem.
10-11-2005, 10:44 PM
#28
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tomboyea123, can you post your 333 rwhp dyno again without SAE compensation ... just the uncorrected data. If you have it.
Thanks.
BTW, I think we cang et to 350-360 rwhp with a Level II headers and our 3.5" exhaust, RRR, B1 cams and springs, piggyback tuning and a few other details.
Gotta find some of the old B1 testing dyno runs on a stock S4 ...
Marc
Thanks.
BTW, I think we cang et to 350-360 rwhp with a Level II headers and our 3.5" exhaust, RRR, B1 cams and springs, piggyback tuning and a few other details.
Gotta find some of the old B1 testing dyno runs on a stock S4 ...
Marc
10-12-2005, 11:58 AM
#30
Race Director
Marc
That sticky flappy sure makes a spike! Its also interesting that the car made more power WITH cats that without it! Thats backwards to how it should be right? 298rwhp/326 tor is very good for just an auto S4 with Xpipe!
That sticky flappy sure makes a spike! Its also interesting that the car made more power WITH cats that without it! Thats backwards to how it should be right? 298rwhp/326 tor is very good for just an auto S4 with Xpipe!