Tabushi

iTrader: (1)

Hi HPI R40 Guys ! :


I run a Yokomo GT4 for about 3 years now ... it has all the hop ups so you can call it a GT4-S ...

Now, even with an old design, the GT4-S its a very competitive car and until now im preparing myself and put all my illusions into participate on the next Pre-World in Brazil on February 2004 with my Yokomo. On the other hand, im getting a lot of positive feedback about the HPI Car ... and im thinking seriously on getting one ... specially cause down here in southamerica we have problems with parts and kits, but with HPI its not a problem here ...

So ... can you talk me a little about the performance of the car on the STOCK form ?, i mean, can i buy one, practice a couple of weeks and participate on a local race and the car will hold up during the practice and racing (obviously starting from the idea that im will not crash the car) ... OR it need the hop ups to be competitive in front of Yokomo's, Mugens, Serpents and other ? ...

Thanks a lot in advance for your help guys ...

PAT

fastharry™

iTrader: (4)

the car runs real good in stock form....it is a little heavy,but drives like it's a lighter car........very nimble on low speed S's..

its held up for me,and I have a hard gallon through it......I broke one axle..and I got t boned with my power on..that was on teh first tank..since then,no problem...

I also bent a rear hinge pin..how I don't know....but the good news is,the arm didn't break...

other then that....no problems.....

its real responsive to tuning changes...and never gets out of control....its as stable as my tc3's..and has more traction in a low traction situation....

there will be hop ups..but the car runs great out of the box..

regg151

out of the box this car out performs most of what is out there today. not to put down the mugen's or associated cars but IMO the out the box feel is very responsive, stable compared to the yok's and mtx's and tc3's I've drivin straight outta the box.

My driving style is very aggressive better suited to large open tracks rather then tight technical tracks probably since I spent so much time drivin in the dirt, but since i've gotten this car i've noticed that it can tollerate my aggressive driving style and stay very controlable in the turns compared to some of the other cars i've driven. now granted I didn't build or setup the other guys cars but I was told they were box stock and set to the specs in the instructions

one thing to take note though I'm running on rubber tires (off my 6 year old NRS4 racer) and this car is amazing me since it barly breaks loose in the rear, can't wait to try it with the kit foams the traction increase will be a real bonus as it should really lower my lap times and let me carve a tighter line around the track

overall I give this kit the you won't be after driving it.

B

iTrader: (13)

Wow, and after all that time the tires dont get hard?

hardcore

regg151

armorall does work wonders, besides they are well worn but still have lot's of tread left.


the old hpi tires were made from some really long wearing rubber (probably why they changed em)

Omar

iTrader: (15)

i like the hpi foams so much that i order 6 more pairs of tires

BossPlaya

The R40 sounds like a real nice car. I went to my local LHS to check it out, but they didnt have one built.

Anyhow, I'm real interested in knowing more about how you can adjust the setup without a setup system. That sounds great to me. How does it exactly work and how many different types of adjustments can you make without any tools?

InitialD

Well, technically this is possible but in practical, more than 5 tooth split will cause the engine to bog when the 2nd gear engages. When using a large split, you need to tighten the 2 speed gearbox for the 2nd gear to engage later in order to get sufficient torque and engine RPM to move the car in 2nd gear.

If the spurs and pinions are based on 0.8 pitch modules like the ones found on NTC3 and the new MTX-3 or the V1RR EVO, then it is possible to use 6 tooth split gearing. This is because the finer pitch in the pinions and spurs give better efficiency in power transfer.

fastharry™

iTrader: (4)

Explain to me how pitch,and not to big of a gear ratio jump will cause the engine to bog....

BossPlaya

nobody gonna answer my question?? wtf??? i've looked all over the web to find a decent explanation of this but couldnt. wow, i thought the guys on the Mugen thread were generally unhelpful...more interested in making inside jokes and talking about KY jelly.

I thoght Fast Harry would at least answer me, considering he's ussually pretty helpful from waht i can tell concering HPI cars.

KMac

He explained it in his last paragraph. The finer pitch gears transfer power more efficiently, therefor you can approximate that a 6 tooth split with fine pitch gears could function as well as a 5 tooth split with coarse pitch gears.

-or another way-

Everything else being equal, a 5 tooth split with fine pitch gears will outperform a 5 tooth split with coarse pitch gears. Whether anyone could realistically notice it, though, is questionable, but the theory is rock solid.

InitialD

Have you run electrics before? I have not. Which is more efficient? 64 pitch gears 48 pitched ones?

A big jump in gear ratio will be hard on the engine. The finer pitch on the 0.8 modules makes the large gear jump possible as not much energy is lost. You have ran the NTC3 before and I would think you should already know that when it came out, the NTC3 was the only car around at that time that was able to run a 6 tooth gear split.!

InitialD

Thanks KMac... You got there first before me!

InitialD

BossPlaya, your question was only posted about an hour back before your reply above. As the car is pretty new in the market, not many people would have the indepth knowledge to answer your question. It is a valid good question no doubt. Just that only a person who has run or built the R40 before would be able to answer you. Patience !

I would think that some of the settings on the R40 can be set without the help of a proper setup tool. I think you can do that with the toe in / out as I believe they have predefined spacers for that but not with the cambers. Don't shoot me if I'm wrong.

AMGRacer

So you dont get an answer in 1 hour so you crack it? Man you have to have some patience.

Anyway like Professor D said the HPI uses spacers so that newbies (like you!) don't have to use calipers to get their suspension symmetrical. Wonder what happens if the spacers have tolerance issues?

Oh yeah you heard the joke about the KY jelly?