PeterPerfect

(Sorry if this has already been covered but the search facility is off-line)

I'm running a Dawes device on my MY99 and am getting very good results.
However there are a lot of posts on Scoobynet raising issues of inlet/outlet temps, AFR, det, maxing the TD04 turbo etc.
I understand that Superchips obtain the performance increase by removing the fuel cut and fitting a bleed valve. I assume they leave the factory solenoid in place.
So, the question is, without monitoring/changing any of the parameters mentioned above, how can Superchips ensure the engine is operating 'safely'....does it have a guarantee ?
I'd expect 'worse' temperatures, AFR, detting and maxing of the TD04 with a Superchip fitted than a Dawes with the fuel cut intact. Do Superchips supply a guarentee with their modification ???

Anyone like to comment ?

john banks

They don't guarantee it. Some seem to think they are OK if you don't yank the boost up over 17PSI. But I would be concerned about no fuel cut if a hose came off.

I would not let one go near my car, a Dawes I am really happy with, as I would be an electronic boost controller.

Perhaps a FCD would be safer with an EBC which has a programmable boost cut of its own.

Given the standard car's limit of about 17PSI it is a problem if you want to run 18 PSI. I wouldn't run over 16 unless I had a completely spike free EBC with the 17PSI fuel cut in place.

With PPP of course, fuel cut is 2PSI higher.

I think the safest power mod of all is a warranted PPP. The midrange is very respectable, and sticking to sensible boost levels is difficult to improve upon. It is also pretty cautious about high revs and the boost - about 2 PSI lower than you can get with a Dawes.

I still think overall the PPP is quite a good bet all things considered.

PeterPerfect

John I note with interest your findings of the PPP psi at high RPM. You say your car is into single figures above 6K....
Prodrive MUST know the deal here....i.e. do they acknowledge a potential problem of stressing the TD04 if running at 13.5psi >6K, or is it as cc pointed out to do with turbo backpressure filling the cylinders with a crappy charge causing det ?
Any thoughts ?


Getting a bit more concerned about my engine now....I guess there is no such thing as a free lunch

john banks

I don't think things are going to go too Pete Tong at only 2 PSI above PPP - thinking about it at 6500 it is about 11 not single - at 7000 it is single figs. I'll get a boost plot on my run @ Star, although apparently they never boost quite so well on the RR.

PeterPerfect

So it just looks like Prodrive are being conservative with the boost to ensure the PPP will not do any 'damage' for at least 3 years.
Are you going to get a boost plot of both the PPP and the PPP+Dawes ?
I agree with your previous post John, about what could have been if Subaru had optimised the duty cycle map for the boost solenoid...perhaps Prodrive asked then not to

john banks

No I will just run with the Dawes for a single run, but I see if I can get a plot of boost and fuelling as well as the usual suspects.

PeterPerfect

It will be interesting to see how the RR fueling compares to your hand crafted AFR gauge readings.