125 replies to this topic

[ArticMonkey]

Sounds expensive. What did near 400bhp feel on track?

[haggi961]

I didn't use all 400 as I set my rev limit to 6k to protect my engine. So it wasn't a fun day for me as the 4.17 gear box and 6k rev limit made for a slow day.

[ArticMonkey]

You're not the first sc owner to not get on with the 4.17 gear ratio.

[chris_uk]

I recon luke was only pushing 280ish. When we dragged down the straight i was changing at 6k also and i drove past him. Might of been less power than that.

[haggi961]

I think the reason I was slower due to my injector leaking as it did feel slow compered to power runs I was doing.

[slindborg]

You're not the first sc owner to not get on with the 4.17 gear ratio.

 

 

thats no surprise.

 

Really Rough rule of thumb:

Revvy (usually N/A engine) = 4+ FD

Less revvy (Usuaully forced induction) = <4 FD

 

With forced induction you simply do not need the extra leverage the higher FD offers, especially when you are then made to shift regularly.

[Exmantaa]

That is a lot of power for your engine specs.   

I only know of 1 other Z22SE build that got 400BHP (399.8...) and that was a full blown turbo conversion running 1.63bar boost.

 

Did you change the 4.17 gearbox ratio's in the OBD power measurement??

 

[haggi961]

I've still got more power if I do the ignition setup as well. How do you mean change the ratio, I'm sure there wasn't a option on the power measurements tab. I told Peter at that start i have a 4.17 gearbox fitted so hopefully he changed it there with my base map.

Edited by haggi961, 10 April 2014 - 09:27 AM.

[techieboy]

Good point, the 4.17 FD box will definitely skew the numbers. Won't affect the map in any way but will make the power calculation think you've got more power as the car is accelerating quicker than with the standard FD box.

[haggi961]

Do you think it can affect it that much? I'm still not 100% that it would change it much.

[Exmantaa]

The OBD power measurement is a measurement of acceleration vs. time, so it will very much skew your numbers if your gearbox ratio is not correct.

It already gives wrong numbers if your tire circumference is deviating...

 

 

Edited by Exmantaa, 10 April 2014 - 09:45 AM.

[ArticMonkey]

Yep, sounds like the 4.17 box is giving you them extra pub ammo. I'd still like to see some figures on a RR from a Dutch ECU car.

[haggi961]

Has anyone got anyway to find or test out for sure that I have a 4.17 gear box fitted as I bought it from atom x so still not 100% that it is. With changing the gear box adjustments on the power measurements where is this option?

[techieboy]

Face it, you haven't got 400bhp.

 

You could probably get a rough idea if you get a couple of good road speed readings at say 3,000rpm and maybe 4,000rpm in 3rd or 4th gear and calculate back (or compare it to a gear ratio calculator chart).

 

Still open to some skew depending on exact tyre sizes though.

[Exmantaa]

I think the reason I was slower due to my injector leaking as it did feel slow compered to power runs I was doing.

 

You have a boost leak passed the lower o-ring seal of the 60lb's? Do you have the grey inserts/adapters fitted with the rail raiser blocks? That should cure this definately.

I think the 60's are a tiny bit taller than the original injectors and therefore may stick too far into the head with possible leakage. Might help to simply raise them a bit  by fitting some washers under the rail mountiings. (Maybe elongate the mounting holes for better fitment as the injectors are under an angle.)

Edited by Exmantaa, 10 April 2014 - 09:59 AM.

[haggi961]

I will be happy if I havnt got 400bhp lol. Just want to know what my engine running so I can figure if I need a bigger pulley or not. I remember reading somewhere that at a certain mph that it revs slightly higher with the 4.17 gear box but can't find the information.

[techieboy]

At any given speed, your engine will be doing more rpm's with the 4.17FD.

[haggi961]

I think the reason I was slower due to my injector leaking as it did feel slow compered to power runs I was doing.

  You have a boost leak passed the lower o-ring seal of the 60lb's? Do you have the grey inserts/adapters fitted with the rail raiser blocks? That should cure this definately. I think the 60's are a tiny bit taller than the original injectors and therefore may stick too far into the head with possible leakage. Might help to simply raise them a bit  by fitting some washers under the rail mountiings. (Maybe elongate the mounting holes for better fitment as the injectors are under an angle.)

My injector leaking is because of this so I've spoke to Peter and he says use a couple of washers and raise it buy 2mm, I take its the same thing as the raiser blocks? Do you know where the raiser blocks are for sale so I can buy a set?

[techieboy]

These are the theoritical speeds vs rpm's for the 4.17 gearbox, with 225/45 17 tyres.
 

[haggi961]

At any given speed, your engine will be doing more rpm's with the 4.17FD.

If anyone is using there vx today could they please tell me what there revs are at say 30mph.