nize

i like to live life on the edge.

nize

A.Wayne; would bad/worn piston rings cause those fluctuations? i did notice the motor's burning oil and leaking some most likely from the oilpan gasket. it's got over 220k miles anyway.

Geneqco; i am running the stock fuel pump with the stock 2.5 fpr and using 55lb siemens injectors. i'm considering going to a 3bar to get better spray.

anyone know where to get this for cheaper?
http://www.jegs.com/webapp/wcs/store...1_752319_11903

A.Wayne

yes, if you had a bad cylinder , but you would have known if so, it would be smoking and mis firing on the dyno . compression/leak down test would confirm this. A bad head gasket will cause this also ... I would first look for a boost leak

nize

i've already tested all the vacuum lines for a boost leak and did not find any.

oh wait, i haven't tested the exhaust plumbing for leaks yet. hmm... what's the best way to test this?

porschefig

I was just mentioning it b/c it sounded like I was reading your graphs wrong..

Geneqco

Yes, i though you were running stock pump... so, once you go to 3.0 fpr your injectors will probably outflow your pump by around 50%... ie the limitation of the pump would be like running injectors that are around 37lb and may be a limiting factor for your HP. Talk to Vic about the WALBRO, they don't cost much and have plenty of flow.

nize

i thought the stock pump was more than adequate for up to 400whp. is this not true? i really need to get that digital fuel pressure gauge to figure this part out.

Geneqco

Based on the flow test in the worshop manual, i would not have thought that. You have to remember that as you run more boost the fuel pressure must also increase and as this happens, the pump's capacity to flow is reduced. The test for 850 cc in 30 seconds works out at 102 litres per hour @ 2.5 Bar. If using a 3.0 Bar fpr and running close to 1.5 bar of boost, total pump pressure becomes 4.5 Bar. Looking at flow curves for the 044 and Walbro pumps, I'd expect the stock pump to only flow around 80 l/h at this pressure. It is true that that test is for minimum flow... so, if you have a very good pump that has not had too much use, it may support more than that - I have heard of 400 hp being made with a stock pump, but that doesn't mean every stock pump would do that. With 220k miles, and 20 years, I wouldn't expect your pump to be pristine.

For the money (Vic has them for $140... maybe he'll do you a deal since you have his turbo) I wouldn't waste my time with the stock pump.

Here's a thread:

https://rennlist.com/forums/showthre...ghlight=walbro

nize

mad tyte JDM upgrade for the new year;