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The dark shall be with us
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Discussion Starter #1
I always thought these cars need more power to beat other cars because the negatives get to your head too when you hear it over and over but lately I have noticed these cars are actually quicker than I thought. I have been roll racing my car often and it's surprisingly the hell out of me. One night I raced a 650whp charger with a pro charger and I slowly walked on him by a fender. Other night I raced a 2018 mustang gt 10 speed with some mode and I pulled on him a little. Those cars make 423 whp stock. Last night I raced another one making 495whp with skinnies and it beat me by about a fender. I don't know how much I'm making but I looked up Ray's dyno and max I could ve making would be ~450whp at 24psi with my cast wheel ported dr650. Mine doesn't hold 24 psi. More like 22 psi. I got a 5 speed on so that helps a bit since I don't have to shift. The mustangs shifter 2 times when I was in 3rd gear. Lol these 10 speeds shift so fast. If it was a 6 speed, I probably would have beat him since he said he beat 6 speed like it's no tomorrow.

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Yes they are a lot faster and far more capable than most give them credit for.

I just took a good buddy for a short blast through a local canyon in mine. He has a built 500WHP EVO VIII with Ohlins and super sticky tires.

He expected mine to be faster than his EVO (and it is) but what really surprised him was the lateral grip and control I get through the twisties. He wanted to know what special tires I had on - my answer "9 year old Michelin Pilots lol".

Its hard to beat our footprint, low C of G, AWD and AWS, keeping it all planted and controllable WOT mid-corner.
 

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Correct but I think the AWS we have actually hurts cornering.

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We'll have to agree to disagree on this one.
 

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One fix at a time
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Surprisingly, I usually get a decent amount of respect from actual car people not the ones that only like one platform but will appreciate anything well built. I have my car turned down due to lifting the heads but at around 500whp it still surprises quite a few how hard such small turbos pull.

They also can’t believe how planted the car is in the corners. Even after coil overs and upgraded center diff surprisingly wider rear tires made almost as much of a difference in grip as doing the center diff upgrade. I’d like to do 275 fronts and 300+ rears vs the 255/285 combo I have now.
 

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Turbo cars are faster at similar power to weight ratio because of the nature of turbo power. Na cars may make 600whp for 500 rpms while the turbo car making 500 makes within 10% of that 500hp for 3,000 rpms.
 

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Surprisingly, I usually get a decent amount of respect from actual car people not the ones that only like one platform but will appreciate anything well built. I have my car turned down due to lifting the heads but at around 500whp it still surprises quite a few how hard such small turbos pull.

They also can’t believe how planted the car is in the corners. Even after coil overs and upgraded center diff surprisingly wider rear tires made almost as much of a difference in grip as doing the center diff upgrade. I’d like to do 275 fronts and 300+ rears vs the 255/285 combo I have now.
Same experience here. Real racers and car people do "get it" and show respect - mostly because the BS stops when the lap timer starts.

You are dead on regarding lateral grip. A modestly lowered VR4 provides almost shocking levels of steady-state lateral g even on stock 245 x 18s. Adding upgraded differentials (Quaife, Torsen & KAAZ) extends this to transient-state lateral g all but eliminating front push, without resorting to massive camber and grip-limiting sway bars.

I have my motor built for 700WHP but have it turned down to 515WHP - because that's really all you can use effectively on a racetrack without needing ceramic rotors and major aero upgrades.
 

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One fix at a time
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Same experience here. Real racers and car people do "get it" and show respect - mostly because the BS stops when the lap timer starts.

You are dead on regarding lateral grip. A modestly lowered VR4 provides almost shocking levels of steady-state lateral g even on stock 245 x 18s. Adding upgraded differentials (Quaife, Torsen & KAAZ) extends this to transient-state lateral g all but eliminating front push, without resorting to massive camber and grip-limiting sway bars.

I have my motor built for 700WHP but have it turned down to 515WHP - because that's really all you can use effectively on a racetrack without needing ceramic rotors and major aero upgrades.
Definitely. About 500whp I can give it full throttle coming out of the corners but with the boost turned up to 25 psi I was getting too much back end happy wheel spin. I could get some R compound tires but I don't think those are legal on the street let alone it would kill some street characteristics.

You don't happen to have the Kaaz do you? I've got the Quaife and Torsen but probably wouldn't get the Kaaz unless I was road racing. I'm already grip limited as it is.
 

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The dark shall be with us
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Discussion Starter #12
Definitely. About 500whp I can give it full throttle coming out of the corners but with the boost turned up to 25 psi I was getting too much back end happy wheel spin. I could get some R compound tires but I don't think those are legal on the street let alone it would kill some street characteristics.



You don't happen to have the Kaaz do you? I've got the Quaife and Torsen but probably wouldn't get the Kaaz unless I was road racing. I'm already grip limited as it is.
True. I have yet to discover the limit of my car around the corner and I have pushed my car as far as my balls allowance I have pretty big balls. Lol. The car roles a lot but it doesn't lose traction even when I bunch it while coming out of corner before turn the wheel straight. But of course this is at the exit and entrance ramps and not the track. The only time I got understeer was when I was auto crossing at a corner that changed direction and going down hill while turning and that was just a power understeer.
I really want to try to race around a track but I don't think my car can do laps after laps without heat issues.
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Definitely. About 500whp I can give it full throttle coming out of the corners but with the boost turned up to 25 psi I was getting too much back end happy wheel spin. I could get some R compound tires but I don't think those are legal on the street let alone it would kill some street characteristics.

You don't happen to have the Kaaz do you? I've got the Quaife and Torsen but probably wouldn't get the Kaaz unless I was road racing. I'm already grip limited as it is.
The OEM LSD was shot so it would spin the inside rear in corners. So I installed the KAAZ as well - I have set the car up for canyons, track days and possibly a couple of road racing events like the Virginia City Hill Climb.

You definitely know the KAAZ is there at low speeds and low power cruising but is a lot better after I did the full break-in procedure.
 

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True. I have yet to discover the limit of my car around the corner and I have pushed my car as far as my balls allowance I have pretty big balls. Lol. The car roles a lot but it doesn't lose traction even when I bunch it while coming out of corner before turn the wheel straight. But of course this is at the exit and entrance ramps and not the track. The only time I got understeer was when I was auto crossing at a corner that changed direction and going down hill while turning and that was just a power understeer.
I really want to try to race around a track but I don't think my car can do laps after laps without heat issues.
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You might be surprised. I ran mine regularly at track days here in Nor Cal for a couple of years in 90-100F heat with not much more than Porterfield racing pads. The OEM brakes are the biggest weakness, so it was two sets of pads and a pair of rotors per track day - which got old and expensive fast.

On a race track, heat only becomes a serious issue with our cars when you push the power past 350 WHP (>450 crank HP) - after which brakes, splitters and larger radiators are pretty much mandatory.
 

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The dark shall be with us
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Discussion Starter #15
Yeah I make more like 450whp now. I wonder why these cars dont do well with heat when racing. I wonder if it's the thermostat housing or the pump or even the radiator.

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Yeah I make more like 450whp now. I wonder why these cars dont do well with heat when racing. I wonder if it's the thermostat housing or the pump or even the radiator.

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Its because of several factors:

1) 450WHP is almost double the OEM (250WHP) heat load. So we need to expell twice the heat or suffer overheating.

2) we have a transverse V6, around which it is notoriously difficult to manage cooling airflow for headers and turbos - and that adds to the heat load.

3) Our cars were designed before hood vents were a thing - many (probably most) high output motors now come with hood vents and lots of under-hood air management devices.

4) the latest generations of high boost motors (e.g. AMG, Audi, Toyota/BMW) have headers integrated into the heads, ultra short turbo piping and integrated air/water IC's and massive radiators all of which help with heat management and reduce lag.
 

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The dark shall be with us
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Discussion Starter #17
I was Talking about the cars during the same time too. Gtr Supra and such can do long laps without overheating unless making 800-900 hp. I think it's the flow in the thermostat housing and the water pump. Each coolant port on the head is same size as the single radiator hose that is supposed to supply it with coolant and the water pump housing can barely flow enough coolant.

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Same experience here. Real racers and car people do "get it" and show respect - mostly because the BS stops when the lap timer starts.

You are dead on regarding lateral grip. A modestly lowered VR4 provides almost shocking levels of steady-state lateral g even on stock 245 x 18s. Adding upgraded differentials (Quaife, Torsen & KAAZ) extends this to transient-state lateral g all but eliminating front push, without resorting to massive camber and grip-limiting sway bars.

I have my motor built for 700WHP but have it turned down to 515WHP - because that's really all you can use effectively on a racetrack without needing ceramic rotors and major aero upgrades.
Thank you for this info and I'm sure in the next few years my son and I may pick your brain on this stuff. :D First step is to get the car properly sorted stock for now. :D
 

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I was Talking about the cars during the same time too. Gtr Supra and such can do long laps without overheating unless making 800-900 hp. I think it's the flow in the thermostat housing and the water pump. Each coolant port on the head is same size as the single radiator hose that is supposed to supply it with coolant and the water pump housing can barely flow enough coolant.

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I was puzzled by that as well but i believe the 800-900 are the "hero numbers" i have yet to find a racetrack where you can actually use 800-900 WHP in a production based platform. I'm excluding drifting from this comment.

I have the same thing with my track bike - its a 2017 R1M tuned to deliver 205HP. When I download the telemetry after a track day or a (very occasional) race, it shows that I maybe used all 205 HP for 10-15 seconds per lap - and I'm up there with the fast guys.

Getting back to heat management. For our platform, there are two separate sets of heat to manage:

1) Cooling the water from the motor and the turbo housings. from my experience - the key here is a larger radiator and adequate control of cooling air through it. I can run at >500WHP all day long at a constant 184F with just a Mishimoto radiator and either the stock under-tray or a splitter.

2) Cooling the charge air. This is by far the biggest challenge on our platform. It involves managing multiple heat sources, providing the coolest air possible to the filters and extracting levels of heat energy that the platform wasn't designed for.

In my case on 91 pump gas in 90F CA track temps, at 515 WHP my AIT is 170F and constant - pre-methanol injection. At 550 WHP my AIT gets beyond 180 and keeps on rising. I can crank the boost up to get a one off hero AWHP number - but you can't use this on a road course and the heat puts you into a state of diminishing returns. You have to pull more and more timing and add more and more fuel to cope with ever increasing IAT.

This is what I'm working on now :)
 
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