MSD BTM Install Problem

[JRSCGSR]

Hi guys, I just got my MSD BTM installed by Dynamic Autosports and for the vacuum line that runs to the BTM so that it can sense the boost, the mechanic plugged it into some nipple on the throttle body. This doesn't seem to be the correct location to me because the sc is mounted after the throttle body and to me this doesn't seem like it would measure the boost correctly. When I expressed my concern to the mechanic, he told me that everything after the throttle body is one plenum, and that it should be fine.

How can I test to make sure that this vacuum line is connected correctly? I tried to listen for detonation, but I couldn't hear anything while driving. I remember somebody saying that you should be able to feel the BTM retarding the timing while I'm driving by turning the knob back, but I didn't really notice anything. My timing is set to 16 BTDC at the moment and I'm afraid that it's a time bomb just waiting to explode. I bought some octane booster and threw it in to make me feel a little better.

The mechanic told me to run my boost guage connection to the spot on the throttle body that the BTM is connected to at the moment to see if it would register on the guage, but I couldn't find any 1/8" vacuum lines at Kragen or Autozone. The salesperson told me to buy some 5/32, which is slightly bigger, and when I connected it to the guage, it didn't want to read past 0 vacuum/boost. I believe this was because the vacuum line was too big and air was escaping during the boost, but I'm not sure. Can anyone verify whether or not this connection is fine?

Anybody have Jim's number, I figure if anybody can help me, it's him. Thanks. Sorry for the long post.

Jon

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97 GSR, JRSC...of course, RSR Header, Tanabe G power Medallion, AEM Intake, 17" Advan RG's, CRV Crank Pulley(Soon), BTM(soon), J&S(soon)

[This message has been edited by JRSCGSR (edited March 31, 2000).]

[Holden]

That doesn't sound right to me. I know the bypass valve connects there, but it just uses vacuum to hold the valve open. Vacuum probably goes to zero at that spot, but I don't think it sees boost.

Think about this: On 94-95 GSR's, the vacuum fitting your BTM is connected to goes to the PCS. Do you think the PCS sees boost too?

I would tee off the OEM FPR vacuum line.

And back your timing off to 8-10 degrees until you fix it.

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Greg Holden
96 GSR, JSRC, Walbro regular pressure pump, AEM cai,
RSR headers, Greddy PE, Brembo Cross-Drill rotors,
DC Sports Rear Strut Tower Brace (junk!), Yoko AVSi

Greg Holden's JRSC Install Site

[Heretic]

Have a digital camera? Take a picture and post it.

Easy way to check. Get a friend and put the car in neutral, unplug that vacuum line and put your finger over it while your friend opens the throttle. You should build boost free revving quickly with WOT throttle. Feel boost?

Hooking up the boost meter would be best though.

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Ryan Earl
'99 Turbo SH
NTPOG - North Texas Prelude Owners Group
My Page

[zip]

If the nipple from the TB was where the conection was made to the BTM, then the unit will never sense boost! The SC is placed after the TB hence no boost sensed by the MSD. You should tap from the pressure switch w/ a 1/8 tee.

On a sidenote, John how much and where did you buy your MSD6 BTM? Thanks.

[lundgren]

There is no boost at the TB, it must be at the intake manifold.

[SC SiR]

If there was boost at the throttle body, our check engine light would go on. That's why the turbo guys have check valves.

I have an MSD 6BTM on my car and connected it to the OEM FPR vacuum hose via 5/32 tee.

I know it works coz I have boost gauge. Also at WOT at full boost, I turn down the retard and I gain power.

However, I'm still running 8BTDC. The moment I go 14BTDC, the engine starts to knock even with 6BTM of max retard. It knocks on tip in, but my A/F meter is reading rich. Anyone got a comment on this?

[Civic TSI]

To SC SiR:

Are you sure your BTM read all the boost ? Or maybe it's hookup improperly. If you're running 14BTDC, at 6psi the BTM should retard 15 degrees. If I set mine to max, when I start boosting, it's like I'm holding the brake at the same time. I never had to go higher than .8 degree per pound of boost, and I'm running 16BTDC.

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To 24 PSI, and beyond !
HS Le Club

[redline]

I have some knock at tip in shown on the J&S but nothing that i can hear. i am running 14BTDC with about 3/4 degree retard per pound on the 6btm. I have my FP set at 66psi which helped a little (up from 62psi) Just easy into the throttle till about 4000rpm and then i do not show any knock.

I will play with the Vtec controller on the way home from work tonite to see if that make a diff.

k

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Project Dark Side is Here!!!

JRSC 8psi, Walbro HP pump, MSD BTM, J&S, STR rail, etc...

[JRCivic]

Correct boys !!! No boost is seen at the throttle body and/or gooseneck... only vaccuum thru zero boost (atmospheric pressure). I hate to hear that a shop as big as Dynamic could make a huge blunder like that. You must get manifold pressure...

Zip - I really like that idea to use the "Tee" at the pressure switch hole... mind if I use it ???

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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph

[JRSCGSR]

Okay, just wanted to thank all you guys for the quick responses. I just got back from Dynamic and they fixed the problem. THey tapped into the OEM FPR line, I believe. There were two vacuum lines leading out of the manifold, one goes to the JR FPR and my boost guage is there, so they tapped into the second vacuum line. Looks like it leads to the original FPR, so everything is all good now. Thanks to everybody for the input. My car now feels so much nicer from the start, no hesitation at all, I like...

Zip - I didn't get the 6BTM, I just got the BTM because I couldn't justify dropping 330 bucks at Summit, so I just got the BTM for like 160 plus handling I think.

Jon

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97 GSR, JRSC...of course, RSR Header, Tanabe G power Medallion, AEM Intake, 17" Advan RG's, CRV Crank Pulley(Soon), BTM(soon), J&S(soon)