As the summer rush has slowly started to taper off, we have had some time to put into Kels, the Speedstar sponsored 350z. As you have read, all season long I have been developing and building the new HR block, as the platform to move forward from. The reason to move to the HR was simply for a block that could sustain higher RPM without the risk of crank failure.
Well, upon assembling the engine we realized that somehow the boxes for the pistons were mixed up, and we received pistons with a shorter pin height, designed for a longer stroke crank (the 3.7L VQ37 crank). The options at that point were to either send back the pistons, which would involve removing the heads (which were already almost fully assembled), or buy a 3.7L crank and give Kels a little bit more displacement. This was actually a lot less work, as we would be able to leave the pistons and the rods in the engine, and not need to remove the heads. It also meant we would most likely see a nice power gain.
I’m happy to report that all went well with the engine assembly, start-up and dyno tuning. Previous worries about trigger issues proved to be unfounded – the MoTeC controlled the ECU perfectly up to 9000rpm. Cam control and all other functions, including spark with the HR coils also proved to be non-issues. It’s so nice when things run smoothly! Our belt routing layout without the A/C in place proved to work without a hitch, and the cooling system modifications also had no problems.
On to the dyno for break-in and tuning – the first thing I noticed was the incredible torque. The engine used to have peak torque values of 285-290lb-ft with the Jenvey ITBs and large cams. With even larger cams and the exact same intake and exhaust system, the engine is now making over 320lb-ft of torque. That’s huge! It’s also likely too much – we need to shift that torque higher in the RPM to keep the power from falling off up top. Either way, I was only doing the partial throttle tuning at that point and was very excited to see the engine producing that much torque. I had high hopes. A few more hours of late night tuning and the final number was 400whp on the dot. We tried the shorter trumpets, but found that all they did was shift the power over, not make any more of it.
Happy with the results, we rushed to make a Cayuga test day prior to CSCS. At the test day, the car ran really well, but the gearbox was not shifting as it should have been and I had to really slow-shift the box. It ended up costing 1-2 tenths per lap. We threw the softer S8 Michelin’s on the car and put down a 1:12.7 – 8 tenths faster than my previous best time. Check out the video:
The test went great, and the weather could not have been better. We prepped the car for CSCS and ran it there – but that race report is for another time, and I’ll cover how the rest of the OnPoint tuned guys did at that time. Only a week after CSCS, we got the car prepped and ready to race at Mosport in the GT Sprints. The was the first time the car would run in the fastest category for closed wheel cars in Ontario – GT1. Trans-Am cars, tube frame cars and the fastest race machinery around all gets lumped into this unlimited class. Last year the Z ran a 1:24.8, and depending on who would come out to race, that could be enough to run on the podium.
Part of the pre-race prep was on some more dyno time, to sort out why the Z didn’t seem any faster in a straight line at CSCS. As it turns out, with the taller HR block the hood was very much interfering with the ITBs and we were losing over 20whp when closing the hood. We were left with no time so the hood hack had to be done at Mosport – in a desperate attempt to make more power!
Practice went well, there was so much traffic out there that I don’t think anyone put in a clean lap, but the Z was running strong and felt good with the new rear wing and splitter extension. In fact – the car had too much under-steer even with the wing fully trimmed out! Qualifying is where we would really see what the Z had. The temperature was getting warm and the sun was out, and the track was fairly slick, but I felt the car should have been substantially faster than it was last year, so I figured a 23 might still be possible despite the warm and humid weather.
As it turns out, a 24.5 is the best the car would do, and the fastest she would go all weekend. That’s not bad, considering that the car had the exact same straight-line speed as last year. The car picked up a fair bit of high speed push, it simply doesn’t have enough front downforce – there was no way I would be able to go through 4 almost flat, as I was able to last year. Some more front aero will be in order for next year.
A 24.5 was enough to put us on the outside pole – ahead of some very impressive American V8 machinery, including ex Trans-Am and tube frame machines. The one car that beat Kels, was a tube frame Mercury Merkur – not sure if it was any relation to the XR4ti that ran in IMSA in the late 80’s, but it sure looked the same. This Merkur had a V8 with a wild amount of power, the thing must do 270+ up the back straight at Mosport. A very cool car, indeed.
So as we got Kels ready for her first race of the year, we attempted to open up the hood some more and install some mesh to prevent the trumpets from sucking in any sort of race debris – as I would like this engine to last some time! The rest of the car looked good. A little VP MS 109 in the cell and we were ready to rock. It was time for Kels to show those V8’s what she could do. The car was also very loose on the new pavement that the track put down in corner 3 and 10, so we made some adjustments to hopefully help that out, including softening the rear bar and adjusting the corner balance of the car and a small damper adjustment. Race time.
Green flag – I take the Merkur around the outside of 1, knowing that my only hope to get a lead on this car is to build a gap through the corners so that when the straights come I have some hope of staying ahead. On that opening lap, the Merkur gets by me on the back straight, but I was able to keep him behind me at least half way up into the corner on the back straight. I was all over him through 9/10 and 2/3, and managed to make a pass on the outside of 4. Kels has lots of grip and told me we could do it. The Merkur didn’t pass me that time on the straight, as I drove down the middle of the track and I suppose I made it slightly confusing to determine what side to pass on. As far as I know, there are no rules specifying you can’t drive down the middle of the straight. Oil went down in 4 and 5 that lap, so I was fairly cautious through there. A lap later the Merkur would fly by at full speed – without any delays from yours truly. The speed he went by Kels, a fairly fast car, was incredible! However, he got caught up by some traffic in 9, and I went around the outside of both of them. But, he passed by on the front straight and got ahead into corner 1. I then closed the gap through 2 and passed him on the inside of 3. This was starting to be pretty awesome racing! The Merkur would go by again on the straight, but again I would pass him on the outside of 9 – the Z had so much grip there it was ridiculous. And that was it, the Merkur would never pass Kels again, and we won overall against some very heavy machinery (there were 2 other 600+whp cars behind us while all of this battling was going on). Don’t take my word for it, watch the video:
It was a great race weekend, and I have to thank all of my great friends for helping get Kels ready over the last year. Andrew Stittle, Liam Kirby, Fizzer, Trevor Nevils, Jesse Tong, Speedstar and all of their employees, Rene and the guys from Centerline – I don’t think Kels would have been ready to go without these guys. It was an awesome, low-stress race weekend to wrap a very busy season of professional racing. It was also super nice having my Fiancée Nicole and Apex at the track with me! I also must thank Charles Spivak who came out on short notice and took the best pictures of my Z I’ve ever seen at Mosport. Thanks Charles!
Kels. The little Z that could.
Category: Racing Stories