Infiniti G20 Project Racecar MotoIQ 

Project Infiniti G20 Racecar: More Power

By Steve Rockwood


Road racing is a thrill that has few equals in the wide world of wheels.  Drag racing, unless you're talking nitro cars, is a thrill that quickly loses its lustre.  Losing a drag race while road racing, however, is an exercise in abject frustration.  Nothing will make you hate your car more than nailing that apex and throttle point perfectly to extract every ounce of momentum coming out of the corner, only to watch your opponent sail right past you on a long straightaway and park it in front of you in the next corner.  Project G20 Racecar's tired engine, with over 130,000 miles on it, was destined to only let us down.  We needed to fix it.

Check out the rest of our Project Infiniti G20 Racecar build here!

MPTCC Infiniti G20 Acura RSX Nissan Sentra
Project G20 about to lose a drag race.

Before we dig in to what is really a Part 1 of our quest for more power, we need to caveat this article with the fact that this car was originally set up for the now defunct NASA SE-R Cup.  The SE-R Cup had open engine modifications, with the only real rules being that you had to retain the stock engine in its normally aspirated form, and could not have less than 16 lbs per horsepower measured at the wheels.  The rules were written in this manner to allow anyone with a junkyard engine, and a few breathing mods, to compete with the guys who treat racing like Gran Turismo and rebuild their motors twice a season.  It worked.  Quite well, in fact, as perennial winner Tom Paule hammered on his junkyard engine with absolute impunity for many seasons before defecting to the Honda Challenge once SE-R Cup went kaput.  That car would likely still turn a competitive lap time for that series.  Our car then transferred into NASA's Performance Touring (PT) series, which assigned a points value to every modification, and then classed your car based on the original car, and how recognizable it is from its original form (your total modification points).  Needless to say, the rules kept us in a stock engine, with a stock head, and breathing on its own.  With our state of mods, our car slotted in as a fully optioned PTE car, or a PTD car with room for improvement.

MotoIQ Infiniti G20 Project NASA SE-R Cup Performance Touring
Project G20 in full SE-R Cup livery.

The first, and most obvious, modification under the hood of Project G20 was a beautiful all-stainless header from now-defunct Hotshot Performance.  With stepped primaries whose length was optimized for the more aggressive cams available for the SR20, short secondaries, and a 3" collector, this header was as close as you could get in power production to a custom-fabbed full race header.  Hotshot built this header as an answer to cheap knockoff companies copying their original design – these unscrupulous companies' headers fit on Hotshot's jig to perfection.  Unfortunately, the SR20 performance aftermarket's ship had sailed by this point, and Hotshot only made a few for some very lucky customers. This header has served us quite well over the years, and has even survived a direct hit (well, after some minor repairs) from a freshly liberated connecting rod and subsequent engine fire.  Not a single crack has developed, despite the severe heat cycling found in racing, and we sorely miss the days when you could get a mass-produced (well, relatively) all stainless header with stepped primaries for under $600.  RIP, Hotshot.

MotoIQ Project G20 Hotshot Gen VI stainless header
The Hotshot Gen VI header was truly a work of art.  If it were still a product you could buy from a vendor, rest-assured it would be MotoIQ Certified Legit.

Our Hotshot header dumps into a custom 3" race exhaust built from a 3" aluminized Walker resonator and a mild steel U-bend fabricated by your humble author.  Building a racecar exhaust is generally a simple affair: make it exit somewhere behind the driver, point it away from the car, and if you've got the room/weight to spare, try to shut it up some.  While our setup was by no means quiet, it did succeed in keeping our ears from bleeding with earplugs on.  One thing to consider when building an exhaust for your racecar: don't make your exhaust too quiet.  Keep in mind that you're probably sharing the track with a number of other cars in different classes, driven by drivers who may or may not notice you next to them.  Having a loud exhaust will almost always notify your fellow racers that you're next to them.  Just keep in mind that, like the turn signal, you can inform others of your presence, but it's still up to them to do something with this information.

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Monday, November 28, 2011 5:17 AM
great read guys. big things for next season im guessing.
Monday, November 28, 2011 6:47 AM
Cmon, don't be shy and show us a dyno chart! :P
Wes Dumalski
Wes Dumalskilink
Monday, November 28, 2011 6:56 AM
Nice article Rockweed.... Like the valvetrain tech! Also what did the car dyno. at with these mods?

Lastly... What ARE those moron's doing in the last picture... Getting ready to throw out candy on the parade lap?
Monday, November 28, 2011 7:01 AM
What?! No clip of the new awesome sound?
Monday, November 28, 2011 7:23 AM
I must say, that is the greatest sound ever! Especially when those BWW, Corvette driver's are seeing your Sentra tail lights fade into the distant turns. mmmmm...... Better yet, how about that time when Rockwood, me, and Pang and other various FF guys were pissing off the (I'm driving my Maserttai! ) guy. I love it. The Classic DB track day guy. Trailer's his Maseratti with a Porsche Cayenne. Then gets his ass handed to him by a bunch FF guys. Such sweet track day justice. :)
Monday, November 28, 2011 7:26 AM
Next time someone goes to eBay looking for a deal on a new header, intake and such .. remember Hotshot and think twice about it. Every time you buy a knockoff on the cheep you help destroy another tuning company that actually put blood, sweat and profanity (Cuz Hotshot never cried) into the products we all enjoy.
Dusty Duster
Dusty Dusterlink
Monday, November 28, 2011 8:18 AM
"Loud pipes save lives"?
Mike Kojima
Mike Kojimalink
Monday, November 28, 2011 9:28 AM
The SE-R market is a prime example of how cheap people not supporting the industry ruined it. Their is no SE-R development anymore and the segment is dead, dead dead. The only development is for race cars and we don't make it available for the community like the old days.

If a company asks me about making Sentra parts, I tell them don't bother. No one will buy them and if they do, they will get knocked off and the SE-R owners will promptly buy those.

Hence one off KW Motorsports suspension, trick suspension parts and etc are just for me. One guy in Arizona knocks off my parts and its sorta annoying, but I guess since i won't make them for the public it's not that bad.
Monday, November 28, 2011 10:17 AM
@ Wes/Adrian: Sorry, no dyno chart. We dyno'd the car once at CA Speedway for tech, and found it the plugs were shot afterwards. The car made 151whp then, and picked up 5mph on the oval the next day with new plugs, so much ASSumption is 160-165-ish WHP. We've been too busy racing it to dyno the poor old girl. :)

@ SR20FREAK: Yep, though I blew my motor up that day, which pissed them off more since I got cheap car oil all over their track.

I think this about sums it up:


@ Dusty: Pretty much. Loud pipes also get the guy you're hounding to constantly know you're there. On the opposite side of the spectrum, the HPD/APD Acura TSX is too quiet with a full exhaust.

@ Mike: That about sums it up. That header and JWT's C6M camshafts were the last hurrah at some really trick SR20 parts. After that, you're either looking at racecars, high power turbo cars, well-built street cars and then...

The "99 percenters" (lol) out there that rock the eBay "I/H/E" and cut springs, y0!

Monday, November 28, 2011 11:43 AM
Whatever happened to the SR20VE motor I gave you?
Monday, November 28, 2011 12:01 PM
@ turbosneeze: Wait, huh? I've only received one SR20VE in my lifetime, and a certain large feller whose initials were TO built it. That you big feller? ;-p

If so, that motor is in Martin's hands now. Well, sort of. The bottom end let go, so he rebuilt it to crazy levels. I think there will be a series of articles on it in the future...
Der Bruce
Der Brucelink
Monday, November 28, 2011 1:41 PM
Wow, great stuff Steve! That 1st engine shot shows one CLEAN engine!

I hadn't realized the SE-R community has taken such a hit. It seems, to me anyway, that a lot of the smaller or B-spec type cars don't get a whole lot of support anymore from the industry or even "cheap people". Especially in these economic times, you'd think we'd be seeing more and more of the affordable pocket rockets popping up.
Monday, November 28, 2011 3:50 PM
I was wondering what you did on the rack side of the power steering. I have a p10 that I removed the power steering on about 4 years ago. I just kept the fluid in the rack and looped the lines. 68K miles later still works fine but I've always wondered if I should have done something more.
Monday, November 28, 2011 4:27 PM
Sorry @Rockwood... my question was for Mike Kojima. I thought he had put the SR20VE I gave him in the G20... (this is Yuji btw Mike).
Martin Gonzales
Martin Gonzaleslink
Monday, November 28, 2011 4:29 PM
@trbobrk = That's exactly what we did on the rack side of our PS system. Been holding strong for a few years of racing so far with no issues whatsoever.
Monday, November 28, 2011 10:10 PM
Woot, that pic of the Sentra shows the rear tyre off, and the inner front tyre unloaded..

For situations like these will you correct the suspension / geometry? Or is it just because that corner really is tight?

Balls-out driving *thumbs-up*
OMG Its Weasel
OMG Its Weasellink
Tuesday, November 29, 2011 7:31 AM
I've always been under the thought that tight corners in lightweight FWD cars will raise the inside back wheel when not accelerating, especially right handers in LHD cars and vice-versa.
I don't know how this specific car is setup, but most fast FWD cars I've driven have super stiff rear suspension to keep weight over the fronts as often as possible. The side effect of the stiff setup and minimized weight transfer over to the back two wheels is three-wheelin'. It's really bad in rear-trailing-arm Hondas of the 90s. At one point I swore my rear wheels were simply acting as a weather vane for the fronts.
Rear-trailing Hondas hardly have the travel in the rear that this G20 has, so I can only assume this theory is why.
Tuesday, November 29, 2011 9:17 AM
@ Adrian: It's a G20! That's the same car this article's about.

And what OMG Its Weasel says is mostly correct. The rear will always be in the air when not on the throttle. That picture was probably taken exactly when I lift for a split second at the top of that corner.

As for the front tire in the air, that was because we had WAY too much rebound dampening dialed into the car. What you see there is probably that wheel in the air because we hit a bump, and the rebound dampening didn't allow the wheel to travel back to the ground, which is a bad thing.
Mike Kojima
Mike Kojimalink
Tuesday, November 29, 2011 3:28 PM
Our cars hardly lift the inside rear wheel if at all. Lifted tires are not providing any grip. If you set up an FF car correctly it won't lift the rear.
Thursday, December 01, 2011 8:07 AM
Good read and progress throughout.

Sorry for this OT bit;
Rockwood, I've been trying to PM you for sometime. I keep getting an error saying unauthorized to do so. Could you please contact me.

Thursday, December 01, 2011 11:43 AM
Just shoot me an email:

(my first name) at motoiq.com
Monday, December 05, 2011 3:59 PM
This will always be my favorite project car here!!! Keep up the great work...
Sunday, January 01, 2012 7:07 PM
Well if people in the industry block further developement of parts becuase of idiots in the past that kind of ruins it for the rest of us doesn't it. It is much less satisfying following builds with one off parts us mortals 'dont deserve' and cannot get. Hotshot and such all happened before I owned my nx but now I'm stuck with the fall out from a few idiots! Great.
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