XKR Super G... Going for Mach 1
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Chebesto......Great info...But here is my problem....the last time I did this event I did it in a car that was about to become a fulltime race car. It still had the seats ... But had a massive GT1 wing. They stuck me in a class with cars that cruise at speeds over 200 mph.
I have driven this car at very high speeds and have had others with as much or more racing experience as I do... And alll feel that the rear is lacking a diffuser and a wing. Terry and I are working on a diffuser... But if I want to stay in a certain class... I need to look as close to stock with the body as possible....
remember.... I don't need to stay over 190 for long...just enough to scrub off some time off the clock...
I will test the diffuser that Terry comes up with and see what we come up with....I have a car that has Massive downforce and it all comes from the bottom. I am just hoping to get the same from this setup.
We will let you know what the results are when we test... Good or bad
Edit*** As far as the wheels....they are designed for high speeds...you will see the same rims "SV10" on Labo's, Ferrari's, Porsche....thats why I use 20's to get that extra step. I will look up those books you listed.
I have driven this car at very high speeds and have had others with as much or more racing experience as I do... And alll feel that the rear is lacking a diffuser and a wing. Terry and I are working on a diffuser... But if I want to stay in a certain class... I need to look as close to stock with the body as possible....

remember.... I don't need to stay over 190 for long...just enough to scrub off some time off the clock...
I will test the diffuser that Terry comes up with and see what we come up with....I have a car that has Massive downforce and it all comes from the bottom. I am just hoping to get the same from this setup.
We will let you know what the results are when we test... Good or bad

Edit*** As far as the wheels....they are designed for high speeds...you will see the same rims "SV10" on Labo's, Ferrari's, Porsche....thats why I use 20's to get that extra step. I will look up those books you listed.
Last edited by XKR; Aug 25, 2009 at 09:45 AM.
Hmmm... not sure my W/M injection is going to be enough for next ZdayZ airstrip event. 
I'm sure I can get someone to unhook a coupler, again.
Looking good Mike, Sharif, and crew.
I'm sure I can get someone to unhook a coupler, again.

Looking good Mike, Sharif, and crew.
Last edited by rcdash; Aug 25, 2009 at 06:24 AM.
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Just playing a little catch up on this thread. 
Looking good XKR.
Aero at 200 is important but his cooling will be paramount imo. I was running 155+ for extended periods in my ST Z heading through the desert in Utah (literally 115 F) and was watching guages like a hawk and had to back off a few times to let it cool off a bit. Your EGT's will be crazy but the inlet air and coolant temps will be a good guages for you see. Will you be running any type of "virtual Dash" where you'll be able to see things like this?
Also, I run the SV-10's and they are EXTREMELY well made. Had them for years now and even doing long trips, high speed runs, and through cities (NYC for example) I haven't bent one or damaged one (knocks on wood)...and I should have running a 30 series tire on the rear. They are sturdy.

Looking good XKR.
Aero at 200 is important but his cooling will be paramount imo. I was running 155+ for extended periods in my ST Z heading through the desert in Utah (literally 115 F) and was watching guages like a hawk and had to back off a few times to let it cool off a bit. Your EGT's will be crazy but the inlet air and coolant temps will be a good guages for you see. Will you be running any type of "virtual Dash" where you'll be able to see things like this?
Also, I run the SV-10's and they are EXTREMELY well made. Had them for years now and even doing long trips, high speed runs, and through cities (NYC for example) I haven't bent one or damaged one (knocks on wood)...and I should have running a 30 series tire on the rear. They are sturdy.
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Just playing a little catch up on this thread. 
Looking good XKR.
Aero at 200 is important but his cooling will be paramount imo. I was running 155+ for extended periods in my ST Z heading through the desert in Utah (literally 115 F) and was watching guages like a hawk and had to back off a few times to let it cool off a bit. Your EGT's will be crazy but the inlet air and coolant temps will be a good guages for you see. Will you be running any type of "virtual Dash" where you'll be able to see things like this?
Also, I run the SV-10's and they are EXTREMELY well made. Had them for years now and even doing long trips, high speed runs, and through cities (NYC for example) I haven't bent one or damaged one (knocks on wood)...and I should have running a 30 series tire on the rear. They are sturdy.

Looking good XKR.
Aero at 200 is important but his cooling will be paramount imo. I was running 155+ for extended periods in my ST Z heading through the desert in Utah (literally 115 F) and was watching guages like a hawk and had to back off a few times to let it cool off a bit. Your EGT's will be crazy but the inlet air and coolant temps will be a good guages for you see. Will you be running any type of "virtual Dash" where you'll be able to see things like this?
Also, I run the SV-10's and they are EXTREMELY well made. Had them for years now and even doing long trips, high speed runs, and through cities (NYC for example) I haven't bent one or damaged one (knocks on wood)...and I should have running a 30 series tire on the rear. They are sturdy.
You know it.....temps in Navada is brutal....Thats why I am happy Sharif did that oil cooler setup...plus the Koyo and the other cooling mod. I did not want the Oil cooler and Rad to share the same air flow.
I have the Camp2 and the Defi setup with the alarm so the co-pilot can keep his eyes on the road map warning me of upcoming bends

I agree...the SV10's is top notch....very well made. I am running the 25 profile tires in the rear....so I am sure if I hit any kind of pot hole....the rim is finished.


I am going to start calling Sharif everyday and ask him that. I did it on the other build
...
Last edited by XKR; Aug 25, 2009 at 01:56 PM.
Last edited by ttg35fort; Aug 25, 2009 at 03:55 PM.
Chebesto......Great info...But here is my problem....the last time I did this event I did it in a car that was about to become a fulltime race car. It still had the seats ... But had a massive GT1 wing. They stuck me in a class with cars that cruise at speeds over 200 mph.
I have driven this car at very high speeds and have had others with as much or more racing experience as I do... And alll feel that the rear is lacking a diffuser and a wing. Terry and I are working on a diffuser... But if I want to stay in a certain class... I need to look as close to stock with the body as possible....
remember.... I don't need to stay over 190 for long...just enough to scrub off some time off the clock...
I will test the diffuser that Terry comes up with and see what we come up with....I have a car that has Massive downforce and it all comes from the bottom. I am just hoping to get the same from this setup.
We will let you know what the results are when we test... Good or bad
Edit*** As far as the wheels....they are designed for high speeds...you will see the same rims "SV10" on Labo's, Ferrari's, Porsche....thats why I use 20's to get that extra step. I will look up those books you listed.
I have driven this car at very high speeds and have had others with as much or more racing experience as I do... And alll feel that the rear is lacking a diffuser and a wing. Terry and I are working on a diffuser... But if I want to stay in a certain class... I need to look as close to stock with the body as possible....

remember.... I don't need to stay over 190 for long...just enough to scrub off some time off the clock...
I will test the diffuser that Terry comes up with and see what we come up with....I have a car that has Massive downforce and it all comes from the bottom. I am just hoping to get the same from this setup.
We will let you know what the results are when we test... Good or bad

Edit*** As far as the wheels....they are designed for high speeds...you will see the same rims "SV10" on Labo's, Ferrari's, Porsche....thats why I use 20's to get that extra step. I will look up those books you listed.
So, the results will be good.

Chebesto, did you look at the information that I sent you???
yea i got the pdfs. thanks.
i was going to comment on it when i had time later this evening.
if you are going out of your way to re-do the exhaust piping, you can actually have the exhaust gas exiting your car help you create a lower pressure zone in the rear of the car so that the airflowing through your diffuser is being sucked out faster, but you'll have to encorporate the mufflers into your diffuser and be slightly above the venturi channels.
as far as the wheels go. i think you misunderstood me.
with the offset and width, your wheels peek out when viewed dead on from the front, you'll need to get a fairing to cover up the front of the wheels, such that the air can flow around the front of the tire/wheel.
Green arrow show the direction of the air flow from the wheel/tire.
blue is natural air flow from the front of the car,
Red is the areas in which you need to add to reduce the amount of air flowing forward that might screw with the natural airflow you're trying to use for your diffuser...
and no offense to the KurumaZ G bumper, but that will buckle under high frontal stress, you'll need to get an FRP, or CF bumper with reinforcements underneath so it doesn't bow in.. also make sure your front diffuser is bolted in to add more support for your front bumper to maintain its shape..
i was going to comment on it when i had time later this evening.
if you are going out of your way to re-do the exhaust piping, you can actually have the exhaust gas exiting your car help you create a lower pressure zone in the rear of the car so that the airflowing through your diffuser is being sucked out faster, but you'll have to encorporate the mufflers into your diffuser and be slightly above the venturi channels.
as far as the wheels go. i think you misunderstood me.
with the offset and width, your wheels peek out when viewed dead on from the front, you'll need to get a fairing to cover up the front of the wheels, such that the air can flow around the front of the tire/wheel.
Green arrow show the direction of the air flow from the wheel/tire.
blue is natural air flow from the front of the car,
Red is the areas in which you need to add to reduce the amount of air flowing forward that might screw with the natural airflow you're trying to use for your diffuser...
and no offense to the KurumaZ G bumper, but that will buckle under high frontal stress, you'll need to get an FRP, or CF bumper with reinforcements underneath so it doesn't bow in.. also make sure your front diffuser is bolted in to add more support for your front bumper to maintain its shape..
Last edited by Chebosto; Aug 25, 2009 at 04:23 PM.
Chebosto, is the 1/2 inch lateral aspect of each wheel really going to amount to a significant increase in drag given that the incremental cross-sectional area would be miniscule compared to the entire front of the car? I think attacking the low hanging fruit (i.e. where 20% effort affords 80% gain) seems practical. Going beyond that seems onerous but perhaps that's required for 200 mph?
Last edited by rcdash; Aug 25, 2009 at 05:00 PM.
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yea i got the pdfs. thanks.
i was going to comment on it when i had time later this evening.
if you are going out of your way to re-do the exhaust piping, you can actually have the exhaust gas exiting your car help you create a lower pressure zone in the rear of the car so that the airflowing through your diffuser is being sucked out faster, but you'll have to encorporate the mufflers into your diffuser and be slightly above the venturi channels.
as far as the wheels go. i think you misunderstood me.
with the offset and width, your wheels peek out when viewed dead on from the front, you'll need to get a fairing to cover up the front of the wheels, such that the air can flow around the front of the tire/wheel.
Green arrow show the direction of the air flow from the wheel/tire.
blue is natural air flow from the front of the car,
Red is the areas in which you need to add to reduce the amount of air flowing forward that might screw with the natural airflow you're trying to use for your diffuser...
and no offense to the KurumaZ G bumper, but that will buckle under high frontal stress, you'll need to get an FRP, or CF bumper with reinforcements underneath so it doesn't bow in.. also make sure your front diffuser is bolted in to add more support for your front bumper to maintain its shape..
i was going to comment on it when i had time later this evening.
if you are going out of your way to re-do the exhaust piping, you can actually have the exhaust gas exiting your car help you create a lower pressure zone in the rear of the car so that the airflowing through your diffuser is being sucked out faster, but you'll have to encorporate the mufflers into your diffuser and be slightly above the venturi channels.
as far as the wheels go. i think you misunderstood me.
with the offset and width, your wheels peek out when viewed dead on from the front, you'll need to get a fairing to cover up the front of the wheels, such that the air can flow around the front of the tire/wheel.
Green arrow show the direction of the air flow from the wheel/tire.
blue is natural air flow from the front of the car,
Red is the areas in which you need to add to reduce the amount of air flowing forward that might screw with the natural airflow you're trying to use for your diffuser...
and no offense to the KurumaZ G bumper, but that will buckle under high frontal stress, you'll need to get an FRP, or CF bumper with reinforcements underneath so it doesn't bow in.. also make sure your front diffuser is bolted in to add more support for your front bumper to maintain its shape..
The car will spend more time in the 120 to 150 mph area and then up the speed on the straights.The car has had the once over by a race shop here in houston where the cage and some weight losing work will be done after it leaves Forged Performance.
There will be custom work done to clamp the front bumper into the area of the OC and IC. The bottom of the bumper will have a piece that will be welded to the bottom of the IC and then screwed to the bumper.
The reason I picked this shop is because they do alot of the Texas Mile cars and also Salt Flats monster cars....He agrees with what we found....the rear has to have a difuser. From there we take it to a wind tunnel and see what else we can find.
Like I said...no offence taken....input is always accepted in this thread
Last edited by XKR; Aug 25, 2009 at 05:44 PM.
if you are going out of your way to re-do the exhaust piping, you can actually have the exhaust gas exiting your car help you create a lower pressure zone in the rear of the car so that the airflowing through your diffuser is being sucked out faster, but you'll have to encorporate the mufflers into your diffuser and be slightly above the venturi channels.

I'll take a look at this to see if this will work for us.
Thank you Cheston!!!
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lol