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Rod Penrose's New car project

46350 Views 291 Replies 69 Participants Last post by  twaluminum
Australian drag racer Rod Penrose is building a new bug body style race car!

To be on the track in 2009!

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Well , after a few rain outs over here I finally ran the car last weekend . This was a test day with 200 other cars so only 3 runs on the day .
The 1st run was not good after hitting the shift button into 2nd gear 3/10th's of a second after the car left the line , the car filled with black smoke ( clutch dust ) I left with a .070 light , a 1.51 in the 60 ft , 6.03 @ 122 1/2 track and 9.37 @ 139 at the end . All data was normal so refueled for another pass .
The 2nd run I left the line with 2 hands on the wheel so I could not accidentally hit the shift buttons , reaction was a -.022 red light , 1.36 in the 60 ft , 5.55 @ 127 1/2 track and an 8.74 @ 149 at the end . I felt the car nose over at the 1000 ft mark and after checking all of the data I could not see a problem .
The 3rd run the reaction time was a .063 , 1.37 in the 60 ft , 5.9 @ 115 1/2 track and 9.42 @ 141 full track . I felt the car starting to misfire and got off the throttle and coasted with the early shut off .
I have pulled the plugs and found 3 out of 4 plugs melted . I suspected that this may have started during the 2nd run and went totally off during the 3rd run . According to the data I am all good on the EGT's , all good on the A/F ratio and suspect that maybe the timing map may need some attention . I am back in the US in 4 weeks time and will bring some data with me to try to find some answers . I need to know how much timing I need to have as I am at almost 32 lb's of boost and have 22 deg. advance . The intake temps are around 45-48 deg. and I still have more boost pressure that exhaust pressure , ROD.
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wow..8.74...that's a world record for a non turbo VW...awesome
He's turboed big guy!
Nice run Rod. 32# and still - on the exhaust? What turbine are you using?
RodPenrose said:
I felt the car nose over at the 1000 ft mark and after checking all of the data I could not see a problem
Been there, done that and hurt parts too.

When it does that, if you stay in it, it's gonna hurt stuff. Guaranteed. That's the way methanol is. It's likely it needs more fuel, regardless of what the data shows.

Out of curiosity, what AFR was it showing at that point?
If your way over center on the fueling, the EGT's can cool down on a methanol ca r- extremely lean.
gramazone said:
wow..8.74...that's a world record for a non turbo VW...awesome
Lol been jumping camps so much u losin ur head boy
A few plane tickets & 3 passes 7s easy Thumbs Up

A few plane tickets & 3 passes 7s easy


You better jump all over that offer!!!
Austin Larsen said:
Lol been jumping camps so much u losin ur head boy
dang..i swore that car was super bad
Hi guy's , here is a quick up-date of where I am up to . Before I left for my recent visit to the US , I stripped the engine to find some damaged valves and heads , due to the excessive heat . This was a surprise to me so I was on the ph to Pauter and Mario had cleared his schedule for me to fly in , drop the heads off and have them repaired , rebuilt and finished for me to bring back to Australia with 10 days . Mario had completed the task within the time frame and thanks to Him and Don , Kris and Dave/Daniel Folts , I have been trying to get way too much fuel economy out of this thing . I also sat down with Doug Harvey @ the VW classic to share our data and I now know where I am going wrong . With the info I received from these guy's I am now where I need to be . I have removed around 8-9 degrees of timing and added about 35% more fuel from the original tune maps and now am starting to see some impressive results . This has resulted in the EGT's to drop over 400 degrees and added an extra 52 HP at the wheels with the same boost . The A/F ratio is almost dead flat and now with the individual cylinder trims all of my EGT's are very close to each other . A big thanks to all of the above mentioned guys that took their time to help me out 2 weeks ago when I was there , and I will have my first all VW race day this Saturday on the 1/4 mile in Sydney . ROD .

Shag , to answer your question I will have to get some technical info off Garrett here as it is one of their special GT51R units .

Mike , I have been aiming for an A/F ratio of 5.2-5.4 as I have been using this mark for the past 15 years with the mechanical injection . I now know that this is not possible with the electronic . I now am in the 4.4-4.5 region .
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Great to see things going so well, the new tuneup looks like it's really working Thumbs Up
Was really looking forward to seeing rods car run some good numbers in Sydney after the 11hour drive there only to be rained out, have to wait till October now in Warwick.
Hi Rod,

It was nice to see you during your trip to the States. Looks like you are going to be waaaaaayyyyy closer on your tune. Sorry you got rained out. Keep us apprised of your progress.

RodPenrose said:
I have been trying to get way too much fuel economy out of this thing .
Hi guy's , the car is still in the trailer ready to go , so I have entered a race meeting this Saturday to do some more testing . With a little over 600 HP at the wheels I am confident that I can go a little faster than the 8.74 last time out . I have replaced the clutch plates and floaters so I am a bit nervous on how this will work on the track compared to the seasoned disc's I have been using up until now , I will keep in touch soon . I have also been looking @ some data and I now go from 0-60 in 1.78 seconds , ROD.
Brian , thanks for the link . I presume this is a US magazine , ROD.
RodPenrose said:
Brian , thanks for the link . I presume this is a US magazine , ROD.
Yes it is a US website magazine,not sure if it is in print also

You weren't contacted for the article?
Brian , no , I this I think was picked up from the Turbosmart article they done a few months back .
I am in the process of prepping the car for my first race day in 4 weeks time . I have had some real small problems that have hampered me on the last 2 test days and I think I am ready to now hit it hard . I am starting to use the launch control with the 2 step and I am happy with the tune now . I am starting to compensate each individual cylinder with extra fuel to bring all of the EGT's together and I think that the inlet manifold design is a bit ****** . I will now modify this one into a plenum type to see what difference it will make to the tune . I have 2 lean cylinders ( 1 & 3 ) and 2 rich cylinders ( 2 & 4 ) and can't comprehend why if it is all under pressure . I will now make more air volume in the centre of the manifold near the throttle body , ROD.
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