scooby-tc

iTrader: (2)

Ok heres the story i have an MY98 STi Type R which is supposedly 276bhp from factory first thing i did was to fit an Apexi Power FC ecu,Hybrid FMIC and full decat.This when mapped made 309 bhp at Power Engineering which i thought was about right.Since then i have fitted a TD05 20G (mapped at 1.45 bar),550cc injectors,SX FPR (4 bar pressure),Walboro 255 fuel pump,Gruppe S V2 Headers,Helix flexi up-pipe and of course had it remapped.It went back on the rollers last weekend and made 306bhp (on DD rollers)

My question is what sort of figures should i be expecting with these mods? i would have thought nearer 360bhp.The fuelling on the dyno plot looked fine but the boost only made 1.3 tailing off to 1.15ish,is there something wrong with my car? anything i should be looking for? seems like a lot of money spent for not a lot of power increase

cheers

scoobboy

iTrader: (3)

sounds like you have a leak or a dodgy actuator as if mapped for 1.45 should hold boost and maybe tail off to 1.3 bar at high rpm.

Is it misfiring at all?

Would have thought 360bhp for sure

R4LLY

iTrader: (1)

I would have thought you would have made 360 bhp easily..... Graham aka 911 made 380 bhp and 407 bhp on two different dynos with a 20g and supporting mods.
was that definitely 306 at the fly or was it at the wheels?

perhaps if you contact your mapper and advise he could shed some light on the amount of boost and why it would only be 1.3 bar ....

Jolly Green Monster

iTrader: (4)

so the load on the dyno was nothing like the load on the road and so it didn't make the boost is makes on the road so it made unrealistic numbers compared to what it makes on the road.

The dyno needs to be run with more realistic load.. and in 4th (or the boost needs adjusting to match what it makes on the road, but that is a huge difference and sounds like a dyno issue).

Simon

Peanuts

iTrader: (15)

did you up the WG duty at all to try to hit target boost?

Tidgy

couple of questions, who did the second map? which dyno was it run on to get the second figure?

Peanuts

iTrader: (15)

306 @ 1.15 bar seems pretty good to me!

scooby-tc

iTrader: (2)

Hi Andy,no i didnt touch the WG duty.Jolly Green Monster did the second map.The most recent run where the 306bhp was achieved was at Triton Motorsport.I'm going to try a Dawes device to try to hold better boost on the rollers for next weekend when it goes back on the rollers for a shootout day

Peanuts

iTrader: (15)

Daren, the wastegate duty has to be manually upped because the car wont make target boost on the rollers, Im not sure an MBC will hold you in any better stead, unless you can do a sample run to check what boost it makes and then run again after adjusting the MBC.
When we ran at Janspeed, I had to add a full 18% EXTRA duty to get it to hold boost, and even then it tailed off above 6.5k rpm.
I think it was up to about 82% to get anywhere near the full 1.7bar

Unless you can replicate the road on the rollers then you will always struggle.

Of course, dyno mapped cars are on home turf so can make target all day long
what boost were you making at peak power from the graphs? Im guessing it was somewhere near 6700 rpm, maybe nearer 7k and from your original post, that would suggest you are making 300brake at 1.15 bar which is fairly tidy

SteA

Probably the different rolling roads

Dynodynamics rollers read a lot lower than many others, about 40 bhp in my case Over on the sxoc a lot of us tend to use dyno dynamics rollers now, and if you compare the graphs to previous RR's there are massive differences, with DD rollers reading a lot lower