{"id":699,"date":"1996-05-28T10:57:54","date_gmt":"1996-05-28T10:57:54","guid":{"rendered":"http:\/\/roadraceengineering.com\/blog\/?p=699"},"modified":"2011-08-28T11:02:42","modified_gmt":"2011-08-28T11:02:42","slug":"marc-s-racing-comparison-with-eric-lus-95-gsx-second-race","status":"publish","type":"post","link":"https:\/\/roadraceengineering.com\/blog\/1996\/05\/28\/marc-s-racing-comparison-with-eric-lus-95-gsx-second-race\/","title":{"rendered":"Marc S – Racing \/ Comparison with Eric Lu’s 95 GSX – Second Race"},"content":{"rendered":"
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As a refresher, Eric (EricATCA) and I got together a few weeks ago
\nto see how our cars would fare against each other. We both have 95
\nEclipse GSX’s. Eric’s GSX had several more mods (including a downpipe,
\ncat bypass, and much bigger compressor wheel in his turbo) yet the cars
\nwere at best dead equal; usually I pulled a car length or two on him.
\nThere were no definite answers to the “why”, but one thing that was highly
\nsuspect was Eric’s turbo- it had no modifications to the exhaust side
\nyet had as big a compressor wheel as could fit in the stock compressor
\nhousing. It definitely had heavy lag.<\/p>\n

Since then, Eric has upgraded the turbine wheel plus give it a 10 degree
\nclip, ported the turbo housings, and had the exhaust manifold\/wastegate\/O2
\nsensor housings ported. We hoped the work on the exhaust side of the
\nturbo would make the difference, and that his car would pick up some
\nserious power.<\/p>\n

We got together again this weekend, on a street outside of town where
\npeople have been meeting for street races for at least a decade
\n(probably a lot longer). It’s a nice long (well over a 1\/4 mile)
\ndeserted street, and I felt comfortable racing out there in the daytime
\nwhen there wouldn’t be any other street racers around. Temperatures were
\nhigh, between 90-95 degrees. (Definitely no fun racing with windows
\nclosed & A\/C off!)<\/p>\n

We got in around 12 runs for the day. We paid particular attention to
\ntrying to eliminate as many variables as possible. We both filled up
\nat the same gas station (Chevron 92). Eric had a full tank, mine was
\naround 2.5 gallons shy of full to try and make up for driver weight
\ndifference. In addition to runs off the line and rolling runs where
\nclutch work was involved, we also did several runs from both second
\nand third gear where the clutch was already fully engaged, to try and
\neliminate variance in driving style. For the 2nd gear runs, we both
\nhad the clutch fully engaged and the engines at 3500rpm when we stepped
\non it. Same thing for third gear, except we did it from 3800 rpm.
\nRegarding boost levels, I think the runs were split around 50\/50 between
\nEric running at 18.5 psi & 15 psi. I have no boost control, but I have
\nhollowed out the nipple on the wastegate solenoid on the air box, which
\nallows me to spike up to 15ish psi (after which boost falls down as revs
\nincrease).<\/p>\n

Here’s the list of mods on the two cars. (An asterisk * denotes
\nchanges since last time).<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Eric’s 95 GSX<\/td>\nMy 95 GSX<\/td>\n<\/tr>\n
K&N FIPK<\/td>\nK&N FIPK<\/td>\n<\/tr>\n
Nology Hotwires<\/td>\nMagnecor 8.5mm wires<\/td>\n<\/tr>\n
Trust 2.5″ Exhaust<\/span><\/td>\nRSR 3″ Exhaust<\/span><\/td>\n<\/tr>\n
*Imagine Motors Int pipe upgrade<\/td>\nImagine Motors Intercooler pipe upgrade
\n(Was an HRC unit last time)<\/td>\n<\/tr>\n
Test pipe<\/span><\/td>\nStock catalytic converter<\/span><\/td>\n<\/tr>\n
Buschur 2.5″ downpipe<\/td>\nStock downpipe<\/td>\n<\/tr>\n
EVC (15, 18.5psi)<\/span><\/td>\nMod’d wastegate solenoid, +2psi over stk<\/span><\/td>\n<\/tr>\n
Secondary (inline) fuel pump<\/td>\nStock fuel pump only<\/td>\n<\/tr>\n
T25 w\/ Super60 compressor<\/span><\/td>\nStock T25<\/span><\/td>\n<\/tr>\n
*”T28″ exhaust wheel w\/ 10deg
\nclip, ported housings<\/td>\n		<\/td>\n<\/tr>\n
*Ported exhaust manifold, O2 & Stock manifold\/housings<\/span>
\n wastegate housings<\/span><\/td>\n		<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

As for the results… Unfortunately they are disappointing and create
\nmore questions than they answer. The cars were very equally matched.
\nA couple times Eric pulled ahead of me by 0 to 1.5 car lengths, a couple
\ntimes I pulled perhaps a car length on him. Most of the time we were very
\nequal, with the person who happened to get their foot on the gas a
\nmillisecond before the other person getting a nose up. I think the times
\nI got a little ahead were usually due to my turbo spooling up just a hair
\nfaster (not including the other factors I’m about to mention), but
\nsurprisingly there isn’t much more lag on Eric’s turbo than on mine. I’m
\nsure all else equal there is more lag there, but the downpipe, test pipe,
\nand ported exhaust manifold seem to offset the additional lag created by
\nthe bigger wheels.<\/p>\n

This time around I took Eric’s car for a drive to compare how it felt to
\nmine, so my comments re: lag are based on driving his car and then driving
\nmy car.<\/p>\n

Ok, now to the “other factors”.. We have some unknown variables here that
\npretty much make this weekend’s testing moot, other than to say that
\ncurrently our cars are still pretty equal, whatever the reasons. The
\nfirst variable is a slipping clutch. Eric’s clutch does have a bit of
\nslip (When I did some harder shifts in his car, it was not as crisp as in
\nmine.) I never saw any major slippage, but minor slippage may be occurring.
\nEric will be putting a Centerforce D\/F in soon, so that should eliminate
\nthe clutch variable. Ok, everything that follows is pure (educated?)
\nguesswork.<\/p>\n

“Variable #2” is a complex one. It’s ECU related. It seems like
\nEric’s ECU is retarding his timing, big time. In the races that started
\nin lower gears (1st, 2nd) where he pulled a little on me or kept up with
\nme, he was set at 15psi. When he was set at 18.5psi, I usually pulled
\na car length on him. In the higher gear races (starting in 3rd gear),
\nusing 18.5psi didn’t seem to hurt as much but it certainly didn’t help
\nmuch either. This is a definite sign of a problem, 18.5psi should have
\ngiven him a lot more power, not hurt him. He has a big compressor
\nwheel, going to 18.5 psi should show good gains. He hasn’t played with
\nthe timing on the car yet, but is going to try retarding it a little
\nto see if that makes a difference.<\/p>\n

I’m curious, by the way, if anyone knows the effects that the 2nd
\nO2 sensor behind the cat (in this case, test pipe) might have on the
\nECU?.. Could running a test pipe from an ECU point-of-view be hurting
\nEric? (I’m unsure if he even has his 2nd O2 sensor installed?…)<\/p>\n

Anyways, to me, I don’t think it’s a matter of the performance parts
\non Eric’s car slowing him down or not providing good performance. Take
\na look down the list of mods on his car & you’ll note that every
\npart on there has been proven by many DSM’ers to increase performance.
\nAnd I have seen a 95 with a turbo nearly identical to Eric’s run some
\nimpressive 1\/4 mile times. A better clutch might help things a hair,
\nbut there is something significantly wrong with how things are running.
\nWhat worries me is that there aren’t a whole lot of things to play with
\nto try and correct the problem. Any thoughts on the matter are
\nappreciated!<\/p>\n

That about wraps it up. We plan to get together again in a few weeks
\nwhen the CF DF has been broken in, and after making some sort of change
\n(ignition retard?) that seems to make a power difference.<\/p>\n

Thanks again Eric!<\/p>\n

-Marc<\/p>\n

\n\t\t\t\t\tTweet<\/a>\n\t\t\t\t<\/div><\/div>
\r\n\t\t\t\t\t\t\t<\/a>\r\n\t\t\t\t\t\t<\/div><\/div>
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<\/div><\/div>","protected":false},"excerpt":{"rendered":"

As a refresher, Eric (EricATCA) and I got together a few weeks ago to see how our cars would fare against each other. We both have 95 Eclipse GSX’s. Eric’s GSX had several more mods (including a downpipe, cat bypass, and much bigger compressor wheel in his turbo) yet the cars were at best dead […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[16,33,15],"_links":{"self":[{"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/posts\/699"}],"collection":[{"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/comments?post=699"}],"version-history":[{"count":5,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/posts\/699\/revisions"}],"predecessor-version":[{"id":702,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/posts\/699\/revisions\/702"}],"wp:attachment":[{"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/media?parent=699"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/categories?post=699"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/roadraceengineering.com\/blog\/wp-json\/wp\/v2\/tags?post=699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}