crxgator
Autocross Champion
- Location
- Raleigh, NC
- Car(s)
- All the MQBs
I have no experience apparently.
Sorry. I didn’t mean that.I have no experience apparently.
Thank you for posting that dyno chart.The hpfp is a limiting factor. Here is a dyno of an is12, is20, and is20 with a gti hpfp (nothing else changed between the two is20 files).
It has the same LPFP as the GTi.I guess don't follow the HPFP thing. It's only "squirting" what volume you can get to it from the LPFP in the tank, if the LPFP is already pretty well at it's limit on the 1.8s wiht an IS38, how can the HPFP do much more?
This is the hard-hitting info I come here for! Now it makes sense. I wonder why it seems to be hard to tune for/reliability issues with some of the kits etc. I read so much about? Oh, and 1.8 needs a different vacuum pump as well I believe?It has the same LPFP as the GTi.
Thank you for this. It’s very informative to me.I was sitting maxed out on the 1.8's HPFP for a while, the best I could get out of it was ~320-330 whp on 91, the limiting factor was HPFP in the mid range and injectors in the high range. Here is one of my logs from that time: https://datazap.me/u/meltedsolid/91-4th-gear-pull?log=0&data=2-17-25&solo=8-25-47&zoom=0-471
You can see the high pressure fuel rail pressure drop down to 137 bar, and if I tried to push it any harder it would start cutting out below 120 bar. At 5000rpm+, the injector pulse width is nearly maxed out, much higher and I would start clipping the exhaust stroke (don't really want to go above mid 7's at high rpm).
I've since gone MPI, upgraded the LPFP, and added a flex fuel sensor, and now have plenty of headroom running E85 at high 300's whp.
Also, I have a feeling the increased spool is false, and a trick of the dyno. That would require a change in the airflow, and would have nothing to do with fuel.
Are you being ironic? Sorry, I didn’t mean to offend.This is the hard-hitting info I come here for! Now it makes sense. I wonder why it seems to be hard to tune for/reliability issues with some of the kits etc. I read so much about? Oh, and 1.8 needs a different vacuum pump as well I believe?