Guys,
I am coming back))))
You have lots of questions and guesses at the same time, thus I decided to start not from project history etc., but to indicate any important technical aspect of the car (and trap speed record) and to........ say THANK YOU:bow:
to Robert (aka regular guy) and Drew for their exceptional attitude to me during last 4 years!!!!! This success is in your hands!!! As well as in the hands of Russian workshop
Cartuning, which capabilities allowed to enliven my car and to provide possibility for that record to appear!
Ok, lets start.
1.
Unlim 500+ is
1/2 standing mile competition, where the winner is determined based on Elapsed Time (ET) + Reaction Time (RT) number. Thus, the goal is to pass the distance with the best possible time, not the speed. Easy to understand that those tasks have quite a different launch approach and type of tyres.
Bearing that in mind I would consider my WR for 1/4 mile trap speed as a joke:bellyroll:bellyroll:bellyroll I was not intended in any way to worry about that distance and any associated results..... I made that 1,000 miles roundtrip on my car to win Unlim 500+ in my Supersport rear-wheel drive class, but after several runs understood that the car is 1/4 mile trap speed monster))))))))))
2. You will be surprised but those runs were the first I made after the car was properly tuned. And I did not know wether the engine could go thru all the gears and rpms in that hot conditions (+32C and crazy direct sun).
But I was well prepared to cool down the car in any temps, cause while testing it during the month in my city with +34-40C temps, it suddenly appeared that after 5,000 rpms in any gear the car started jerking due to the excessive fuel in 55-70C intake manifold temps. When the temps went down to 15-20C, all was fine and the monster showed its face....))))
Thus, I took to the competition:
1. 100 kgs of normal ice (for my ice tank).
2. 50 kgs of dry ice (to cool down intake manifold while waiting for the runs).
3. 5 kg ballon with CO2 (DEI Cry O2 system) to cool down the inter-cooler.
And that combination showed the power!!! My intake manifold temps were 13-18C in 32C outside temps... That NUTS!!! At the end of the run maximum temp was 26-28C inside the manifold... So, the power was like in winter and the grip like in hot summer:cool!:
3. Tyres: Hoosier Drag Radials 315/30/18 mounted on Volk TE37 10.5 inch wheels. Pressure was set at 0,87-0,92 bar.
And here I want to come back to the question about low 1/2 mile trap speed in compare to 1/4 trap speed. Yep, there were problems with Unlim speed sensors at 1/2 mile mark and the guys were busy in resolving the problem, but:
- I did have my Racelogic working and it showed 169 mph.
- Other 25 drivers had more or less reliable numbers.
Therefore, I am somewhat sure that so low 1/2 mile trap speed is due to that extremely low pressure in my Hoosiers and their sizing at the same time: after 140 mph speed that pressure did not allow the wheels to "fly" and interfered normal speed acceleration.
However, that "low" trap speed was the 5th at the whole competition and the faster cars were 1,500 whp Lamba, 1,400 whp GTR, 1,200 whp GTR and 1,050 whp Merc E63S 4matic AMG (GAD). And their speeds were also much lower in compare to competition in Moscow... Therefore, +32C made their bad-bad job. So, only guesses....)))))
4. Found the link with recordings of the competition
https://vk.com/videos-69473024?z=video-69473024_456239284%2Fclub69473024%2Fpl_-69473024_-2
By best run is from 7.08.40. Enjoy!
Good run also from 49.50.
5. You could see that the surface is absolutely shitty and the times of PROMOD cars were 10-11s on 1/4 mile instead of 7-8s on any other prepared track... However, my Hoosier hooked up quite well but with less then 1.0 bar pressure only. I tried 1.2 in order to increase trap speed, but there was no start at all and my 1/4 time was 11.4 with 137 mph....
6. As for the car: it is my summer daily driver (not only one, sure) and I passed 98,500 miles already, from which 6,000 miles I already done on that VT4 stroker.
Intrax full coil-over suspension, Dodson SPORTSMAN DCT clutch kit, ARH full exhaust system, upgraded DCT, power-steering and main coolers. Nitto NT01 275/35 front and 315/30/18 rear tyres.
Full weight, full option, BMW Performance seats, full leaver and alcantara interior, 25 litres of water in ice tank, full gas tank, so I consider the competition weight with me (99kgs) was around 1,850 kg....
We could guess only what the car could do with deleting of passenger seat (-27kg), 40 litres of fuel, 10 litres of water and adding Toyo 888 with 2.0 bar pressure, when there would be possibilty to measure 1/2 mile trap speed from 35-40 mph...
As for the possibility to increase 1/4 mile trap speed, that would be no problem up to 145-146 mph at least, I think.... I just need prepared track with glue and 15-20C outside temps.
By the way, what results for 1/4 trap could be nominated for WR? From official competitions only or from Racelogic measurements, provided that the road slope is as required?
7.
Tune: this is the most interesting part. I would be short here: tune was done by Cartuning Russia. During the year after everything was assembled the car was not healthy in terms of tune. Trust me here: proper tune for VT4 stroker project is 70% of success. Respect to my tuner!
8. As for engine itself, I would provide you later with some pics from endoscope which showed that in all cylinders there are some scratches of different types, resulting from unreadiness of either pistons material, walls material or piston clearance to that level of power.... Prior to full load runs the engine was like new born after 5,000 miles passed, but when I started to load the car with 1.07-1.2 boost, some bad things appeared. My guess is that current configuration (sizing, material etc) is not ready to fully overcome heat. Maybe Dinan did not prepare the block as needed while making their Alusil cover... I do not know. Engine saviour is the recommended oil (LAT 20-50): absolutely fantastic!
However, I hope that the discovered scratches is not a big deal from overall perspective and that this engine is able to pass thru dozens of competitions...
PS.
60-130 mph acceleration: I did not measure it, but do have some data from Racelogic, which showed 100-200 kmh from 5.1 to 5.3s. My record on normal road with Toyos 888 was done in that run 0-200 mph and the number was 4,7s from 100 to 200 kmh. Anyway, this car is not the king here, cause I an driving always in MDM-mode only, and the system is working at 2nd-3rd gear shifting (from 97 kmh) thus ruining the real possible result for 100-200 kmh. Where the car is the KING? From 200 to 300 kmh in less than 9sec, whereas VT3 with 700 whp did such job in 13 sec.....
Based on the ET on 1/2 mile I Would say it should be around 188 mph.
